PDA

View Full Version : Glow Plug Controller Broken?


PeasAndCarrots
01-12-2010, 11:42
~30 degrees outside. Engine cold. Glow plugs won't turn on.

Tested circuit:
-Power at both 'B' and 'D' pins in 'Start' and 'Run,' respectively
-Inhibit switch tested as working
-No voltage at pin 'C' or glow plug terminal in any condition.

Questions:
-There was very little resistance through the controller (between positive terminal and "E" pin (ground)) with ignition switch in 'on' position. It reads 5v voltage drop over the circuit. Is this normal?

-Does the controller require require low resistance on the glow plug/wait lamp wire to operate? I.e. if the connectors were loose on one or more glow plugs and/or the glow plug bulb was burned out.

I'm asking because it seems like the controller failed, but from the two manuals I have it sounds like controller failure is rare. It also worked fine the last few times I drove, despite the glow plug light itself not working.

Thanks in advance,
-joe & christy
john8662
01-12-2010, 18:32
What year are you troubleshooting?

Ensure that you have a ground too, a genuine ground (use a test light).

Without knowing your year and what you're working on it's a little hard to troubleshoot, there were different systems.

The easiest way to let us know what you drive is to fill out the signature in the User CP.

J
PeasAndCarrots
01-12-2010, 21:01
Sorry, it's a second-generation system - 1986 Chevy G30.

Test light comes on strong with 12v 2w LED test light. I don't know how much current the ground wire can (or needs to) handle.

I should also mention that the voltmeter, which usually dips when glow plugs are cycling, does not move.

Thanks for the response
-joe and christy
john8662
01-13-2010, 07:55
I'd grab a new controller then, and a replacement bulb for the indicator on the left hand side of the steering wheel near the headlight switch (Gvan).

The controller on your van was used from 85-93, and some current applications.
rustyk
01-13-2010, 18:42
Controllers can and do fail - mine recently failed (NAPA aftermarket) while at an RV park in IL. I had kept the old one, installed it, and was off.