Bad Starter Relay?

Need help troubleshooting...

Went to start up today and, out of the blue, could barely get the prop to move. It would move maybe 20-45 degrees and then seem to get hung up. After a couple seconds with the starter switch engaged I would get a bunch of clicking noises on the firewall and still no more movement on the prop. I tried this 3-4 times all with the same result. Pulling the prop through by hand felt normal... nothing binding up.

I have about 200 hours on everything, have never had cranking issues in the past with my SkyTec. When I pulled the cowl I checked battery voltage and it showed 12.4V, even after having tried to start the plane 3-4 times. So I'm thinking the issue is downstream of the battery. Further, based on an old thread started by Paul Dye, I'm very suspicious of my starter relay. http://www.vansairforce.com/community/showthread.php?t=90977&highlight=relay. Except that this happened with no warning for me, my situation seems similar.

I'm planning to at least try cleaning all the big power wire terminals first, but does the above sound like a starter relay issue to you? It seems like not very many hours for it to fail, but perhaps I wasn't careful enough about not letting the terminals rotate while tightening the cables down when I first installed it.

Regardless, if it is the solenoid, Van's number is 24021 http://www.vansaircraft.com/cgi-bin...90-104-501&browse=electrical&product=start-sw and I think I found the same thing/same number at Napa for $24. http://www.napaonline.com/Catalog/C...oids-SPST-COLE-HERSEE/_/R-TWR24021_0144317761 Just want to be sure they are the same.

Thanks for any help.

The battery is about to die is my guess.

My guess would be the battery as well. With no load, 12.4V doesn't mean it's good. I'd put a charger on it for a while and see how it cranks then.

Vlad said:

The battery is about to die is my guess.

Click to expand...

I agree wit Vlad.

My first flight was 9/2010. In the last couple months I noticed what you described and started to think....gee....why are my Pmag's not firing this engine off on 2 blades? And why is this thing starting to get suck?

Yesterday I changed the battery and today when I jumped in the airplane and pressed "START" - I barely saw 1 blade and the airplane was running!

It had so much cranking power I could feel a major difference.

Voltage? Not issues with the old battery. Probably 12.8+. The old batter just lost its cranking amp capacity.

Put your volt-meter on the battery and (try to) engage the starter. If it goes below 10-11v, it's your battery.

Another simple way to check if it is the relay is to build a big "U"-shaped jumper that you can use to jump across the starter solenoid. Stand well clear of the prop, ignition absolutely, positively, no kidding OFF (disconnect the plug wires to make sure), and then jump across the relay. If it spins - great, then the relay is the problem. If not, then it is somewhere else.

Sounds more like battery to me as well, with the time you state on the components, but worth checking.

I'll check it, but it's a one year old Odyssey that has never had a problem cranking strong (I only replaced the original because I had been troubleshooting a different issue.). 2 days ago it cranked strong too. Plus, why would I be getting the clicking noise on the firewall right where the relay is? I've had a weak battery before that did not exhibit these symptoms. The symptoms I described are pretty similar to the thread identified above.

But, again, I'll hook up the voltmeter first and see what happens when I engage the starter. If that's not definitive, though, the solenoid at $24 seems the cheap place to start.

That clicking noise is the starter solenoid cycling in and out due to marginal voltage. Push the start button, solenoid engages and sends voltage to the starter, voltage drops due to load, the solenoid drops out due to low volts (click). Once it drops out, voltage rises, and reenergizes (click). Repeat several times (click, click, click). Sooner or later the contacts arcing at high amps will weld themselves together. Then you will have a bad starter solenoid.
Might be a bad connection but most likely the battery.

dlloyd3 said:

That clicking noise is the starter solenoid cycling in and out due to marginal voltage. Push the start button, solenoid engages and sends voltage to the starter, voltage drops due to load, the solenoid drops out due to low volts (click). Once it drops out, voltage rises, and reenergizes (click). Repeat several times (click, click, click). Sooner or later the contacts arcing at high amps will weld themselves together. Then you will have a bad starter solenoid.
Might be a bad connection but most likely the battery.

Click to expand...

OK, You guys have me temporarily convinced to start on the battery side. Thanks.

Battery Tender?

alpinelakespilot2000 said:

I'll check it, but it's a one year old Odyssey that has never had a problem cranking strong (I only replaced the original because I had been troubleshooting a different issue.).

Click to expand...

I managed to destroy a PC680 by religiously using a battery tender after every flight. Odyssey had a list of acceptable battery tenders and the one that I was using was emphatically not acceptable.

The symptoms were as you described but a load test after charging dropped the voltage to about 8 volts in 10 seconds.

I stopped using the charger and have not had any problems since.

Just a thought.

john

Hi Steve,

Agree with others--sounds like a bad battery. Put your volt meter on the battery, crank the engine, and note the voltage. I bet it will drop to 10 volts or less--even though it will read 12.4 or better without a load. About a year ago I got two bad new PC680's in a row. Between the first and second "new batteries" I thought it could not possibly be the battery since it was brand new, so I replaced both the master and starter solenoids---same problem. Then I learned you must "load" the battery to test--the "new" battery dropped to 10- volts. It, like the first, was tested and replaced by the vendor but it cost me time and taught me a lesson.

Cheers,

db

high resistance connection??

Sudden development of the problem makes me think that there is a loose or corroded connection in the starter loop. Check ground leg, too.

The same thing recently happened to me... haven't had a problem starting for a long time. Went flying, then landed and fueled up, and then just a click and a strange whine.

Bought and installed a new PC 680 battery. Exact same problem.

Bought and replaced the solenoid on the SkyTec starter (bought at auto parts store)... same problem.

Ordered a new starter relay from Vans -- still in my car, yet to install it yet, but I'll bet that's going to fix it.

Wish I knew that it was available at an auto parts store or I would have bought it at the same time. It looks exactly the same to me.

Slow or no cranking is caused by low voltage. Low voltage can be caused by a bad (or uncharged battery) or by a bad connection. A bad connection will have the same symptoms as a bad battery. A rapid clicking or chattering contactor usually indicates that the problem is the battery itself or a bad connection somewhere between the battery and contactor in either the positive or negative current path. Chattering does not mean that the contactor is bad. However, chattering could lead to premature contactor failure. Sometimes a bad connection will release a small amount of smoke when heavily loaded, as when engine cranking. And sometimes a bad connection will be warm to the touch. If a bad connection can not be found by observation, it can be found by measuring voltage drop while the circuit is heavily loaded. It is safer to disconnect the starter motor and to substitute another heavy load, perhaps an automotive headlamp. Headlamp current, being less than starter current, will allow longer voltmeter testing before the battery is depleted. A large voltage drop indicates high resistance from a bad connection.

Indirectly, the battery seems to be the issue. However, after charging the battery up and getting the plane started, I found that my alternator was showing zero amps on my ammeter, which on my setup shows alt output. I checked the alt field breaker (ok), the big starter and alternator cables (ok), then tried the plug in the back of the Plane Power alternator. All 3 little wires, including their molex pins were loose, somehow having backed most of the way out of the plug! So, it seems that sometime on my last flight that alternator connection had failed, shut the alt down without me knowing it, and drawn the battery down just sufficiently to prevent the starter from having enough power today. Will have to figure out why my Dynon didn't warn me, maybe I had that warning turned off for some reason.

Thanks for the help so far. Will report back when I confirm things are back to normal.

Per Bob Nuckolls, voltage is what you should monitor/alarm. Amps don't really matter. A properly charging alternator should be putting out 13.5+ volts. A battery under even mild load will put out around 12.5 volts, and less as time goes by after an alternator failure.

So if you have a "low voltage" light, or EFIS warning, it should be set to warn at around 13v or so. I like a BIG RED LIGHT in my face for low voltage,( and low oil pressure). I want to know the instant the alternator fails, so I can take appropriate action.

B and C has one, as does Eric Jones at Perihelion designs.

YMMV

ClayR_9A said:

The same thing recently happened to me... haven't had a problem starting for a long time. Went flying, then landed and fueled up, and then just a click and a strange whine.

Bought and installed a new PC 680 battery. Exact same problem.

Bought and replaced the solenoid on the SkyTec starter (bought at auto parts store)... same problem.

Ordered a new starter relay from Vans -- still in my car, yet to install it yet, but I'll bet that's going to fix it.

Wish I knew that it was available at an auto parts store or I would have bought it at the same time. It looks exactly the same to me.

Click to expand...

Update - I installed the new starter relay - same problem.. So, now I have a new battery and new starter relay and new starter solenoid. Today, I sent my starter back to SkyTec. (It is the 149-12LSX model that they don't make any more, so I'm guessing I'm going to end up with something else)

Here's another piece of information that I discovered while changing the starter solenoid... I had the diode installed BETWEEN the S and I terminal and had a wire from the I terminal going straight to ground.

I've been flying for 11 years now and that didn't seem to be a problem, but as I look at the wiring diagrams, it obviously isn't correct. I really don't know how this didn't trip a fuse because it should be a short from the start switch. There must be some resistance out to that I terminal.

I changed the diode to go from S to ground and I is disconnected. Same symptom though.. still doesn't start.

EDIT: I also found this post http://www.vansairforce.com/community/showpost.php?p=956009&postcount=36 which leads me to believe that maybe the inside connection to the I terminal shorted out long ago so maybe it was still more or less working the same way since there was a path to ground through the diode from the S terminal. Interesting that someone else had their starter relay wired the same way as I did.

PCHunt said:

Per Bob Nuckolls, voltage is what you should monitor/alarm. Amps don't really matter. A properly charging alternator should be putting out 13.5+ volts. A battery under even mild load will put out around 12.5 volts, and less as time goes by after an alternator failure.

So if you have a "low voltage" light, or EFIS warning, it should be set to warn at around 13v or so. YMMV

Click to expand...

Yes, if you were forced to monitor either voltage or amps but not both, you would go with voltage as it provides good information on the overall health of the electrical system. Amp readings are useful however; if you turn on your strobes or other electrically driven device and you dont see a rise in your amps, they are likely not operating. Also, abnormally high or low amp readings are idnicators that you may have inadvertently left something on or failed to turn something on.

With respect to the setting for the low voltage light, be aware that a voltage reading at an EFIS or engine monitor may be somewhat lower than the available battery or bus voltage. EFISs commonly have multiple power inputs requiring voltage lowering diodes to be present to prevent power applied to one input flowing back out of the EFIS through a 2nd power input terminal. Thus while everything can be fine and dandy with 14+ volts at the battery or bus, your EFIS reading may be only 13.5 and perfectly normal. Clearly what you want to be aware of is the abnormal condition and have your warning light limits set to identify that.

regards
erich

I learned many, many years ago that as a rule of thumb, with a GOOD battery, you should see 10v or more while cranking Rosie

Went flying, then landed and fueled up, and then just a click and a strange whine.

Click to expand...

That strange whine might have been the starter motor spinning without the gears engaging.

Mich48041 said:

That strange whine might have been the starter motor spinning without the gears engaging.

Click to expand...

The motor wasn't spinning... after I removed the cowl and tried, the gears engaged, (strong click) but the motor didn't spin. The noise is hard to explain.. definitely an "electronic" sound, not mechanical... but I don't know what could make a sound like that.

The Verdict

I talked with Sky-Tec today about my starter and they said the planetary gear was broken, due to a kickback. That's why it wasn't turning, and why I heard the 'whine' sound as the motor was jammed trying to spin.

Interesting that my last start was actually successful.. it must have kicked back but then started anyway? I certainly didn't notice it and everything seemed normal to me on the last start.

Since the starter was over 10 years old - my options were to get a rebuilt LS for $225 or NL for $295. I'm going with the NL. Maybe the replaceable pin will save me if it ever does that again.