PDA

View Full Version : Need help manually firing glow plugs



debles99
11-24-2003, 18:41
98 Chev x-cab 4x4 6.5

Been having problems getting the starter to turn.
Using a remote switch, the starter works fine.
The problem seems to be with the ignition switch, I have a new one ordered that should be here Wednesday. However, I have to get the truck started and drive 30 miles, and it is supposed to hit -27 degrees c in my garage tonight.

Anyway, this afternoon, I managed to get the key to work for once, tested one of the glow plug wires and it had 12v or so on it. Turned the key off, tried again and it worked 3 or 4 more times, then crapped out once again. I smacked the bottom of the steering column with my hand, tried the key and it worked again.

This was about 12:00 noon. Now it's 8:30 pm and I just came in from the garage, now up to almost
-3 degrees c. The key would not work again since I got home at 6:00 pm. I stuck my remote starter button on, turned the key on, pressed the button and after about 8 cranks, she fired up. It is a little harder each time as the temp drops, because if the key does not work, I never get the glow plugs to cycle.

Question is...if I really need to, can I pull one glow plug wire off, jumper it for about 3 seconds with 12v and have it backfeed through the wire to the rest of the plugs, just enough to get the truck started tomorrow morning, or will this fry the glow plug controller.

Maybe it would work better if I unplugged what seems to be like the two spark plug weather caps on the top of what I assume is the glow plug controller, and feed through that wire by itself totally disconnected from the actual controller.

Or is there anyway I can find the relay or wire that actually kicks in the controller and fool it into thinking that the key is on. When I turn on the key, the WAIT light actually comes on for a few seconds like normal, but using a voltmeter, I know that no power was ever hitting the actual glow plugs themselves, and I could not hear the controller click like it did when the key worked.

Any ideas, my hands are getting cold.

Thanks

debles99

ALSAIL
11-25-2003, 10:55
You can manually fire the glow plug relay by providing 12v to two contacts on the relay. My truck is a '95 but I believe yours will be the same. There is a plug with small wires going to the relay. The pink wire is live with ignition on. The yellow wire is live when the PCM gives the signal to fire the relay. The black wire is ground. To manually fire the relay, unplug the connector and apply 12v to the pins where the yellow and pink wires were and apply ground where the back wire was. This is what I use to test the glow plugs.

LanduytG
11-25-2003, 11:51
Put a diode in series with the yellow wire this will keep the 12V from going back to the ECU. Once you have that in you can apply 12V to the yellow wire anywhere between the diode and the relay. You can even take it into the cab and use a switch to operate it from there. Many guys do it this way.

Greg

tvtegtmeier
12-17-2003, 10:39
I need some more info about the diode for this manual switch - is it a RadioShack item? Which direction do you point it?

Thanks,

Tim

DamienJ
12-18-2003, 16:48
debles99
There is a manual glow plug set-up on ebay. You might want to email this guy with some questions, maybe this is the answer to your prob.
Good luck
Damien Johnson US Navy
Happy Hoildays everyone