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Engine Starter Stalling

MMiller said:
Tom,

Before changing the relay, you may want to check the wire crimp and spade connector on the coil wire. The coil ground connection is through the mounting plate, make sure the relay is secure, if you have an older kit with the relay transfer adapter plate, make sure that is secure to the firewall too.

Mike
Click to expand...

Thanks Mike. I do have an older kit, and the firewall does have the wrong bolt pattern for the later start relay, but instead of using the provided relay adapter plate, I just opened up the hole pattern slightly on the relay with a rattail file, and it bolted up fine. Building EAB allowed me to do this, and I was able to eliminate a bunch of superfluous hardware. The relay is secure to the firewall, and I will re-verify the spade connector on the coil wire. I really appreciate your help.

As the saga continues..............Tom
 
todehnal said:
Thanks Sink. I am NOT sure that it is the sprag. I even get this same stall condition when cold cranking with the ignitions off. The sound is like a screwdriver being inserted into a light bulb socket; "zzzzzzzzt"
Click to expand...

Tom, I think that is good news. That sound is more of an arcing sound than mechanical, leading one to suspect a weak electrical connection. Solenoid would be the prime suspect.
 
It has been my experience with cars that a chattering start relay is due to either a bad battery or a bad electrical connection. Terminals should not come off from the ends of the heavy cables when the cables are firmly pulled.
What happens is that there is enough voltage to energize the relay. Then after the contacts close and the starter current flows, the voltage drops due to the bad battery or high resistance of a loose or corroded connection. The low voltage causes the relay to de-energize and the contacts open up. The cycle repeats over and over until the start switch is released. It is similar to the electro-mechanical doorbells of yesteryear. The problem could be inside of the start relay but is more likely due to the battery or cables.
 
Wow!!! Have I been chasing my tail!! Additionally, I have been asking for help without giving enough information. So, here are the fact as provided by some logical diagnosis, along with a discovery. This took some time, as the condition is intermittent, and once the engine spins up nicely, I have to wait until several hours later to make additional tests. You guess it, it has been an all-nighter.

I first spun the starter by applying 12 volts directly to the starter positive lug. The results were that it spun up fine; no problem. That eliminated the starter, and the sprag clutch.

Next test; I placed a jumper directly to the starter solenoid coil circuit ( the small push-on post). The solenoid did not buzz. It offered solid clicks each time that I applied 12 to it. Again, no problem. Starter solenoid looks good.

Next, I went back to the key switch, master on, ignitions off, and I got the prop stall, and buzz from the start relay. Only this time, I happened to be looking at the key switch, and noted that the spar pin light was flashing intermittently, and in time with the starter solenoid chatter. After a few seconds the spar pin warning light remained off, and the engine spun up just fine. Bottom line, the problem is in that spar pin circuit somewhere. It isn't on when I turn on the master, nor has it ever come on in my 120 hours of flight. Only during a start attempt, My problem is that from here I am lost. On the schematic, I see a relay, but I have no idea where it is, or what is causing it to chatter during start, but that is the only way that I can see to flash the spar pin warning light, and interrupt the starter solenoid pick circuit.

I am so excited to know that my problem is not sprag clutch oriented. With some help from you guys, I am certain that I will get to the bottom of this.

Thanks, ever so much for your thoughts..............Tom
 
Glad to hear you are zeroing in on something else.

That is one of the dangers of trying to troubleshoot something based on only written description coming from someone that has been unable to identify a cause.

It sounds like you may have a spar pin switch or other part of the system that is being influenced by vibration.
 
To continue; I just finished going through the spar pin reed switch circuitry, and it is rock solid. Tapping on the pins, rattling the reed switches tugging and jiggling the wiring, and ground raised no issues. I need too move my spar pins well out of their seated position to get a light. That leads me to the switch module, which is where my guess is that I will find the spar pin relay.

To be continued...............Tom
 
Before I go off on a tangent here, does anyone know if you can remove the master/key switch module through the mounting hole from the front, without removing the Skyview, or the avionic top deck??

Thanks........Tom
 
todehnal said:
Before I go off on a tangent here, does anyone know if you can remove the master/key switch module through the mounting hole from the front, without removing the Skyview, or the avionic top deck??

Thanks........Tom
Click to expand...

Pretty sure you'll have to remove the top deck...
 
I have never tried removing the ign. module through its associated hole in the panel, but I think it would fit.
The problem you will likely have is getting the harness D-sub disconnect from the back... that will fully depend on how much service loop you have unrestrained.
 
Tom,
For the spar pin indicator to illuminate the following has to happen;

1) An open at the spar pin input (open mag switch, open wiring in mag switch series circuit, or a bad ground at the right side mag switch ground connection.)
or
2) The relay coil fails (open coil or low voltage)

and there must be power available (Start Fuse)

Relay coils almost never come back once they open, so we can assume the coil didn?t fail. Typical relay holding voltage is 20% of rated voltage, so once picked the relay will hold until the supply voltage drops below 2.4 volts. The Rotax start relay, spar pin relay and spar pin indicator are all on the same circuit, the 2A Start Fuse (or is it 3A now?) So here is an easy test for you, try starting the engine (mags off) while holding the Spar pin button pressed down. A flickering indicator while the engine is cranking normally would likely be caused by a problem in the spar pin wiring. But, if the flickering and buzzing are still present, I would look into the power supply feed (Start Fuse/socket,) it?s unlikely a ground side issue because each of the three components has an independent ground source.

BTW, if the spar pin indicator is flickering, your key switch is not the problem.

Mike
 
Thanks Scott.

Mike, I ran your test as follows:
Master on, Mags off. no spar warning light on. Banged on things thinking vibration, but nothing would cause a flicker.

Pressed spar pin override switch, and activated key switch.
No starter solenoid chatter, and solid engine cranking with no stall, but the warning light does flicker. Released the button and activate the key, and we are back to chattering starter solenoid, and stalled prop.

Can't imagine what could change merely by activating the key switch, unless there is an internal issue with the AV50002 module

Tom
 
This tells us the problem is occurring in the spar pin relay coil circuit. Thanks to Joe, here is a section from his Skyview schematic that shows this circuit.

view
 
Thanks to both of you guys. It sure looks like a very simple circuit, and mine is rock solid until the key is activated. Then all 773H breaks lose. Finding it may prove to be challenging, due to it's intermittence, and the short time that testing can be accomplished, but I'll getter done............Tom
 
Wire F506-22-8 ORN/BLK goes between pin 2 of the AV-50002 and pin 2 of the ignition D-Sub on the AV-50000A. The wire is 22 AWG and is 8 inches long and is colored orange and black. Temporarily short that wire to ground. If the problem goes away, then there is an intermittent loose connection someplace between the point where you grounded the wire and where the spar pin magnetic reed switches are grounded.
An easy way to tap into that wire is to pierce the insulation with an Exacto knife. Then connect a jumper wire from the knife blade to ground.
One of the two D-Sub pins mentioned above might not be seated properly. Or the problem could be pin 5 of the fuselage D-Sub on the AV-50000A. Take the D-Sub connectors apart to see if the pins and/or sockets are seated properly.
The Override switch bypasses the magnetic reed switches and the spar pin relay.
 
Thanks Joe. I printed your test procedure, and plan to follow it in detail. I won't be able to get to it until Friday, but I will post the result. I really appreciate your help. It's been a real tail chasing experience. It's about oil change time anyway, so popping the avionics cover off for your tests will not be a big deal.............Tom
 
Hey Joe!! I was looking at the little schematic of yours of the spar pin circuit, and I came up with a theory. What if the diode that is in parallel with that coil is bad?? Starters are extremely noisy electrically, and wouldn't you think that the induction kick from the starter could cause that relay to chatter with a bad diode?? The wiring in my spar pin circuit seems way too solid to be causing this. Your thoughts??

Any other electronic wizards?? Feel free to chime in. What is the function of that diode? Is it a noise capturing device??
Tom
 
A diode is highly unlikely to fail. Even if it did, it would not cause the relay to chatter. There is no inductive kickback until the the relay is de-energized. And that should not happen unless a spar pin magnetic reed switch opens up.
The most likely cause of the spar pin relay chattering is a bad connection due to improperly seated pins or sockets in a D-Sub connector. Next likely is a bad connection in the magnetic reed switch wires.
 
Focus on the starter issue, get to the exact root cause then see what is left.
Click to expand...
Tom's starter works fine when the Spar-Pin Override button is held in. That points to the spar-pin circuit as the problem. See posts 62 and 63 above.
The majority of electrical problems are due to bad connections, not bad components.
 
Mich48041 said:
Tom's starter works fine when the Spar-Pin Override button is held in. That points to the spar-pin circuit as the problem. See posts 62 and 63 above.
The majority of electrical problems are due to bad connections, not bad components.
Click to expand...

Thanks Joe, I did not understand that this was part of the activation circuit, I thought it was just a warning.
 
The RV-12 has removable wings. If the wings are not securely locked in place, there is an electrical circuit which prevents the engine from starting. An override switch is provided in case the engine needs to be started for maintenance purposes with the wings removed. The override switch could also be used if the spar-pin circuit malfunctions when it is imperative to start the engine.
 
I think I may have it solved. My plans changed, and I was able to get after my buzzing starter solenoid, and flashing spar pin safety light today. Joe, you were right, there was nothing wrong with the diode on the spar pin relay. After removing the avionics cover, and locating the spar pin ground wire in the small ignition harness, I was unable to duplicate the problem. I went ahead and pulled, and reseated both ends of that short cable, as well as the fuselage harness from the AV50000. Also, while I had the short ignition cable out, I removed the end covers, and carefully examined the wires, and pins. All subsequent test showed no failure nor flashing spar pin light. It must have been a dirty D sub pin, or socket. Anyway, everything looks good. This was sure and intermittent, and illusive problem. Hopefully this problem will remain solved, Thanks for all of the help............Tom
 
An interesting thread to follow

Hopefully your troubles are behind you Tom. I expect many of us on here have been following this thread with interest and appreciate all the updates. I for one certainly have a much greater appreciation about the discipline needed to properly trouble shoot an intermittent problem like this. I've had a few minor issues in comparison and have wasted time not being more deliberate in eliminating possible causes. (yes, mostly due to poor electrical connections). Really glad to hear your sprag clutch was not the issue. Felt your pain when that was identified as a possible issue. Last thing in the world I would be looking at to fix would be the spar circuit!
 
Hey Brent, I appreciate your comments. Yeah, I was in a pretty dark place for a few days, but all is well now. I just decided that I was going to get to the bottom of it, one way or another. Fortunately, and with a lot of help from fellow builders, things turned out very positive for us. What appeared like a major issue, turned out to be nothing more than a bad ground connection. These RV-12s are truly fantastic birds, and we have for the asking, an unprecedented support group. How lucky is that!!.....Tom
 
Still No Joy

Mich48041 said:
Let's hope the problem really is fixed and not just intermittently working. Time will tell.
Click to expand...

Joe, I guess your hope wasn't quite strong enough. My starter solenoid chatter came back. So, I took off the avionic deck cover again. This time I added a test ground wire directly to pin 2 of the master switch module, which bypasses the spar pin circuit completely. Of course, being intermittent, I had to put it back together, then wait and see. Well, that starter solenoid is still chattering, but I also noted that with the radio master on, and the auto pilot switch on, both of which have the indicator lights lit, that they also flash when I get this starter solenoid chatter. What is going on?? I must be loosing 12 volts somewhere. Is it possible that activating the starter would cause a week master relay is to falter?? Where to go from here?? My next test will be to wait for a cool morning, and leave the ignitions off. Turn on the master switch, then hook a jumper cable across the master solenoid, and then turn the key to start. If I still get a starter solenoid chatter, then the master solenoid is not the cause. I'll post the results...........Tom
 
A heavy load will cause problems to show up better. That is why I suggested using a LOAD TESTER back in post # 12.
Since pressing the spar-pin override switch caused the problem to go away, I would repeat that test several times to be sure that it consistently allows the engine to start. If so, then the problem is within the AV-50002 Ignition and Start module or its wire harness connectors.
A chattering starter contactor could cause lights to flicker as heavy starter current is rapidly turned on and off.
 
I Know The Cause

Joe, I completed the tests, and I now have a repeatable diagnosis routine that nails the problem to the AV50002, and specifically the contact points on common, and the normally open side of that spar pin relay. Here is how I positively determined that. First, I have a temporary ground wire on pin 2 of the AV50002. That totally takes all of the spar pin wiring out of the picture. Now, if I try to use the key start, I still get start relay chatter, but if I use the spar pin override switch, I get rock solid starting. Take a look at the prints, and you will see that the only item that I am bypassing is the spar pin relay, normally open contacts. This problem has been there since day one. I just kept hoping that it was caused by a very tight engine, and it was a minor inconvenience. Since then, it is steadily getting worse, and I get that chatter on almost every start, unless I use the override switch, even with my ground jumper still in place. Van's needs to fix, or replace this relay.

Looking for comments, and where to go next..................Tom
 
Tom,
Good going narrowing down the electrical problem. Since the AV-50002 has an internal problem, it needs to be repaired or replaced, your choice. There could be a cold solder joint that opens up with cold temperatures, who knows?
 
You're right Joe, repair, or replace. I'm thinking that it just may be a bad relay contact. That use to happen often in the back office equipment that I serviced for NCR a bunch of years ago. I serviced a lot of relay tree sequencers, and such. Swapping out a bad relay was common, and no big deal. From my view down from the top of the AV50002, it looks buried, and it may not be so easy to get to, Anyone been into one?? Besides, I hesitate going into it any deeper, just in case Van's will take care of it for me, but only if I haven't tampered with it. I could certainly understand that. Not sure who to talk to there.

Tom
 
Tom,
It's not contact failure, you are dropping the spar pin relay, we know this because the normally open contact breaks (dropping the starter contactor) and the normally closed contacts makes (illuminating the spar pin lamp.) I agree it sounds like the voltage is dropping under the cranking load.

Can you review some of your Dynon data logs? We want to look at the bus voltage at engine start. These are the entries in the data log field ?VOLTS 1" when the ?RPM? just goes above zero, also of interest may be the data field ?SPAR P CONTACT (V)? at the same point in time. These field names may change based on the software version. This should give us a snapshot of both sides of the spar pin coil.

I have the D180, in the logs I reviewed, my bus voltage at start never went below 10.5 volts. If your bus voltage at start is above 10 volts and spar pin voltage is below .7 volts, and based on the results of the tests you have done so far, I would suggest replacing the module with the spar pin relay.
 
MMiller said:
Tom,
It's not contact failure, you are dropping the spar pin relay, we know this because the normally open contact breaks (dropping the starter contactor) and the normally closed contacts makes (illuminating the spar pin lamp.) I agree it sounds like the voltage is dropping under the cranking load.

Can you review some of your Dynon data logs? We want to look at the bus voltage at engine start. These are the entries in the data log field ?VOLTS 1" when the ?RPM? just goes above zero, also of interest may be the data field ?SPAR P CONTACT (V)? at the same point in time. These field names may change based on the software version. This should give us a snapshot of both sides of the spar pin coil.

I have the D180, in the logs I reviewed, my bus voltage at start never went below 10.5 volts. If your bus voltage at start is above 10 volts and spar pin voltage is below .7 volts, and based on the results of the tests you have done so far, I would suggest replacing the module with the spar pin relay.
Click to expand...

Hey Mike. The AV50002 is the module that houses the spar pin relay. It is also the same module that houses the bypass switch. The bypass switch functions, whereas the spar pin relay does not. I agree with your point that if the contacts were the only issue, the spar pin light would not flash, so the relay must be dropping. The problem is caused by the AV50002. If it was a low voltage problem, the starter solenoid would not pull when I used the override switch. I will investigate, and come up with the procedure for review of the Dynon data logs, and try to post the results. This is a Skyview system, and I have revision 13.0.3 loaded.

Thanks for your help. ...............Tom
 
OKAY!!!! I did the dump. It comes out as a csv file, and I opened it in excel. Wow!! Too much for my pea brain. Here are a couple of facts. The spar pin contacts show values from 0.540 to 0.543. Sounds very solid, as it should be, as I have it directly grounded. But the volts 1 shows a lot of 1,1 volts, 1.2 volts then from 3.6 all over the place up to 12.1. I have no idea what it is telling me. Maybe you could allow me to call you, or you call me, and I can bring this up. I would do my best to give you anything that you need. Not sure, but maybe I could send you one of these files. This is the last one, and there are a total of 8 files.

My cell is 618-541-0775
My email: [email protected]
Anytime is good for me. I'm retired, and thanks for your help............Tom
 
Mike, I'm getting a little better at reading this spread sheet. It looks like my first start voltage in the morning is about 12.1 volts. It drops to about 6 volts as I start, then slowly increases to about 13.8, where it pretty much stay throughout the flight. A warm start also starts at a little over 12 volts, but only drops to about 7 volts, probably due to a quicker start. Does any pf that help?? Tom
 
THIS RELAY is not the one used in the AV-50002, but is probably similar. If you look at the specs, it will pull in with 8 or 9 volts, but will not drop out until the voltage drops to 1 or 2 volts. It is unlikely that aircraft voltage would drop low enough to cause the relay to chatter.
 
Tom,
6 volts is too low. A review of my data logs for my 5-6 year old battery show the bus has never gone below 10.5 volts on start. I would suggest a battery load test before going any deeper into the AV-50002.


Joe,
Yes, I agree with you. A voltage drop to 5.5 volts does not fall below the dropout threshold, its not even close. But the relay appears to be dropping out, but only under starting loads. I don?t know what Van?s is using for a relay in the Skyview. My thought was that they may have changed to a solid state relay, and these have vastly different characteristics.
 
todehnal said:
Mike, I'm getting a little better at reading this spread sheet. It looks like my first start voltage in the morning is about 12.1 volts. It drops to about 6 volts as I start, then slowly increases to about 13.8, where it pretty much stay throughout the flight. A warm start also starts at a little over 12 volts, but only drops to about 7 volts, probably due to a quicker start. Does any pf that help?? Tom
Click to expand...

Tom, regardless of whether this turns out to be the ultimate solution to the chattering problem, voltage dropping to 6 or 7 volts during start sounds abnormal. Probably indicates either a bad battery, or a high resistance connection in one of the connections between the battery and the starter. If it was me, the first thing I would do would be to hook up a known good battery and repeat your tests.

Maybe you already said this in an earlier post, but have you disconnected all the connections on the heavy wires between the battery, solenoids and starter and cleaned and tightened them?
 
All of the connections are good from the battery, through the master, and start solenoids, starter, and back to the battery. I removed every single one, cleaned, and reseated them. I will hook up a different battery, and give it another try. I'm having a hard time believing that a little spar pin relay will drop out, whereas the starter solenoid will remain pulled with this same battery, just by using the spar pin override switch. But, there is a lot that I don't understand. This battery will crank until the cows come home, and keep on trucking. I just changed the oil. Ran that starter several times for a good while, waiting for oil pressure before starting. As long as I used the override switch, it spun like a champ. If that is the case, I would say that it was a poor choice for a staring circuit relay............Tom.
 
I agree with Mike and John that 6 volts is too low. However, can the SkyView data be trusted? I doubt it. My D-180 records data at the rate of once per second. The SkyView would have to record data every few milliseconds to catch the voltage at the low point. During the first second of starter motor operation, the voltage is constantly changing. It takes expensive instruments to capture that data accurately.
I agree with Tom. If there is a problem with the battery or contactors or their cables, then why does the engine ALWAYS start just fine when the spar-pin override switch is held in? My guess is that the AV-50002 Ignition and Start module is defective. But why guess when the starter circuit can be tested for voltage drops? Substitute a heavy load in place of the starter motor, then measure voltage drops along both the positive and negative parts of the circuit. The heavy load should be connected for a short time period to prevent wires from overheating and to prevent the battery from being discharged.
 
Let's see if I can post this picture of my graph. This will be a miracle if it works. After I made the chart the image was very light, so I darkened it with a sharpie, but the graph is accurate. You can see the slow decline in voltage while waiting for the Dynon to come up. The you see the start. Looks like 3 compression strokes, then the start, and the voltage rises.

Tom


img002_zpsggitbrbf.jpg
 
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Thanks Joe! I didn't know about that site. I just looked around it, and found it to be very informative. I will join it and post a query, but I need to join it first. I'll take care of that later this afternoon. Appreciate your thoughtfulness.

Wouldn't it be ironic if all I needed was a new battery?? I plan to take out the battery and run down to Interstate Battery on Tuesday. They're great folks, have load test capabilities, and seem to know a lot about batteries. I would certainly trust his recommendations...........Tom
 
I felt it important to follow up with the latest on my stalling starter. As you know, It was not fixed. Several folks have pointed to the battery, and I guess I was in disbelief. When I used a good jumper battery, the problem seems to disappear. Also, the chart that I It posted didn't tell the whole story, as I thought it would. I did confirm that, without the jumper battery, the Dynon display shows the voltage dropping to 6 volts on start. Obviously my Odyssey PC680 battery sat on the shelf way too long before the first flight. Would you believe 4 years!! It is certainly sulfated. I hesitate to replace it now, as we will be heading South for 3 1/2 months in about 60 days. I do have a de-sulfating charger on it, but I am not expecting miracles. The plan is to start the new flying season with a fresh battery. Thanks for all of the help, and I hope that my experience will help someone else. Bottom line, don't overlook the obvious...........Tom
 
This should be my last post on this subject. My starting was deteriorating even further, even though I kept a maintainer on the battery, so I decided not to wait for Spring, but to bite the bullet, and to order a new one now. The test start after tine installation of the new battery was amazing. Wow!!! Only having Lyc, and Cont. experience, I didn't know that a Rotax was suppose to spin like that!! It sure didn't spin like that before, even from day one. Glad I replaced it, and that this problem is behind me. It was, indeed a lesson learned the hard way. Thanks to everyone for your patience..........Tom
 
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