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Smoke test

tomkk

tomkk

Well Known Member
Good news: no smoke, bad news: most things not powering up.

I applied power to my RV-12 for the first time this morning. Most things did not power up as I expected. Here are some details:

• If it's relevant, the aircraft is in my garage with the wings and empennage off. The battery is fully charged. Fuselage, avionics and FWF wiring is complete except the EGT thermocouples are not connected.
• When I turned on the Master Sw I could hear the master relay pick and the Control Module fan turn on and run continuously
• The Spar Pin red light flashed on briefly then turned off
• The green light on the Master Sw did NOT light
• The avionics cooling fans did NOT run
• The fuel pump did NOT run
• The D-1000T Skyview did NOT turn on.
• I tried turning Skyview on with button 1 but that didn't work either
• I have the backup battery disconnected. Skyview WILL turn on OK on the backup battery
• I turned on the Avionics Sw. The green light did NOT turn on.
• Turned on the GTR-200 - it powered up OK and I could hear the squelch in my headset, so something is working.

Fuses all check OK.

I looked at the schematics and it looks like the cooling fans and fuel pump are pretty much of a straight shot from the power bus through Ignition & Start module and Control Module so it seems like they should come on right away. I'd think bad connection but they're on separate wires close out of the Control Module.

Skyview is a direct cable from the control module so it seems like that should power up with no problem. I checked the pins in both connectors and they seem OK - no pushed pins that I could see. The fact that Skyview powers up OK on the backup battery but not on the main is baffling considering the manufactured cable is all that connects it to the Control Module.

I rechecked all the connectors to ensure they were plugged correctly and pins OK.

I assume the green lights on the switches are supposed to light when the switch is turned on? None do.

Seems like I must be missing something basic but I'm not sure what it might be.

Any thoughts?
 
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Measure the voltage between ground and a fuse with everything turned on. The voltage on the fuse bus should equal battery voltage. A heavy load will make problems show up better. Pull out the 30 amp fuse and connect a high wattage automotive lamp between the hot side of the fuse socket and ground. The lamp should light up. If it does not, measure the voltage at the battery contactor.
 
Thanks. Good voltage at all fuses. It's hard to check power at other connectors because they have both power in and out in the same connector so I can't just unplug and check that power at particular pins. No power on the D-1000T pin 1, though, which should be the main power to the Skyview. I just noticed this thread http://www.vansairforce.com/community/showthread.php?t=122981. I have no power on either pin 1 or 20 with my Master on.

Test light comes on when connected to hot side of the 30A Main Bus fuse. Also comes on when connected to hot side of fuel pump fuse but the pump is one of the things not working.

Looks like there's power out of the Fuse & Switch module to the Control Module.

From the schematics, it looks like the cooling fans pick their power from the fuel pump line out of the Switch module (does that mean the cooling fans are off if you pull the fuel pump fuse like I've read about people doing?) and that looks to be a straight shot from the Switch module, through the Control module.
 
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There is a bundle of wires that connect the AV-50001 Switch & Fuse Module to the AV-50000A Control Module. Shut off the master switch. Disconnect the 25 pin D-Sub connector from the AV-50000A control module. Turn the master and all switches on. Using a small 12 volt test lamp (preferred) or a voltmeter, check each socket in the D-Sub that is on the end of the wire bundle. Post the results here. Shut the master off before reconnecting the D-Sub.
You are correct about the fans and fuel pump being on the same circuit.
 
Just to be precise, the two shelf-mounted cooling fans are on the same circuit as the electric fuel pump. There is also a cooling fan located within the AV-50000A box that is internally powered. Two more cooling fans are located on the back side of the SV panel that are on a thermostat circuit within the SV.

BTW, the electrical system schematic drawing provided on Van's web site is very useful in understanding the RV-12 circuits - just make sure you select the drawing that accurately represents your specific RV-12 avionics configuration.
 
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Mich48041 said:
There is a bundle of wires that connect the AV-50001 Switch & Fuse Module to the AV-50000A Control Module. Shut off the master switch. Disconnect the 25 pin D-Sub connector from the AV-50000A control module. Turn the master and all switches on. Using a small 12 volt test lamp (preferred) or a voltmeter, check each socket in the D-Sub that is on the end of the wire bundle. Post the results here. Shut the master off before reconnecting the D-Sub.
You are correct about the fans and fuel pump being on the same circuit.
Click to expand...

OK, Master: ON, Nav lights: NAV, Landing light: STEADY, Autopilot: ON.

Voltage on all pins on that connector was zero except pins 16, 17 & 18, they were 13.6v. That's Comm power (makes sense, the radio works), Power Outlet (also working) and Start Power (not going to try that).
 
There should be voltage on most of those pins.
It looks like the problem is either inside of the AV-50001 or in that cable that you tested. Disconnect the D-Sub connectors from each end of that cable that goes between the AV-50001 and the AV-50000A. Remove the cable from the aircraft and check the continuity on each of the 25 pins. Make sure all of the pins are firmly seated and do not push out. If it checks out OK, then re-install it and make sure each end is connected properly. If there is still no power, then the problem must be inside of the AV-50001 Switch and Fuse Module.
 
OK, thanks. The cable rings out OK. No pushed pins or anything of that sort. I've already contacted Van's, hopefully they'll get back to me soon.

Thanks for your help.
 
EFIS on backup battery

A couple of weeks ago you turned on the skyview on battery backup and did not know how to turn it off. Did you disconnect something back then that's still disconnected now? BTW how did you turn it off. It's just a chance.
 
PMLviator said:
A couple of weeks ago you turned on the skyview on battery backup and did not know how to turn it off. Did you disconnect something back then that's still disconnected now? BTW how did you turn it off. It's just a chance.
Click to expand...

Sorry, I just saw this. Everything connected that I can see. Actually, I've tried to isolate the S & F module as much as possible to see if that module is doing it's thing correctly. The schematic shows it's really just a power distribution module: it basically has one input (BAT) and 20+ outputs to various places, all of which are contained in the WH-00031 cable to the Control module. I should be able to just apply a voltage to the BAT input and see the appropriate outputs on the WH-00031 pins depending on how I have the switches set (thanks to Joe for that clue). That's not happening with mine.

I did accidentally turn on the SkyView some time ago but didn't remember posting about it, I must be losing it :) Anyway, I checked the D-1000T manual and turned it off with button 1. I also left the backup battery disconnected after that, although I did reconnect it to ensure that didn't have a bearing on my electrical problem.
 
No power

Our fuse and switch module had two solder joints missed on the circuit board, sent it back to vans and the new one fixed the problem. Your problem sounds just like the problem we had.
 
lewy said:
Our fuse and switch module had two solder joints missed on the circuit board, sent it back to vans and the new one fixed the problem. Your problem sounds just like the problem we had.
Click to expand...
Boy, am I glad to hear that! (not that you had a problem - that someone else had something similar). I've been working back and forth with Van's but not much help yet. Glad yours got fixed OK.
 
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