Just a quick glow plug light question

[BigWheelBob]

Hi, thanks in advance for the help. I am not an electrical whiz and am not grasping this problem. My glow plugs have always worked perfect. I even installed a new set last year. Anyway lately my wait light, water in the fuel light and volt meter and gen2 light have not been working. I have power on both sides of the fuse, but none at the light bulbs. During one of the diagnostics I was doing I unplugged the gp card, and all of the lights started working. I went to another truck that I was fairly sure all worked and plugged in that card and same problem. Any thoughts?

 

[MarcusOReallyus]

Um, the card is bad?

Contact member antennaclimber. He sells new cards, and by all accounts, they are better than the originals.

 

[Tinstar]

Buy two if you can.
Keep one for spare.

 

[BigWheelBob]

I'm not 100% on the card being bad. As I said, I borrowed one from a truck that I drove in the past that the glow plugs worked on and it did the same thing. Are you sure? I just hate to throw parts at it hoping it will fix it. Have you seen these same symptoms in the past?

 

[sneekyeye]

You may have a bad ground connection somewhere causing the glow plug controller to back feed 12v . Your wait light should have a constant 12v at the bulb and the glow plug controller grounds the circuit. I don't have the diagrams on my phone, but you can unplug I think it's a five or six pin connector under the steering column and ground one of the wires to manually light the wait light. That will at least tell you if your bulb, socket and assorted wiring is good on the supply side.
The ground circuit for the cab wiring is pretty flaky, I'd check it and clean it. It should be high up on the driver kick panel. With any luck, that might fix your problem.
Let's just ramble on a bit, and I'd also suggest that perhaps all three bulbs are fed by the same 12v trace on the back of the instrument cluster, and maybe unplugging the main plug and plugging it back in will cure your ills.
Perhaps

 

[antennaclimber]

The common element to all of the non functioning items is Fuse #15. Check to see if it is making good contact with the slots that it fits in. The fuse could be good but is not making a good connection in the fuse box. Try replacing the fuse, it may be intermittant.

 

[BigWheelBob]

I found the problem. Yesterday the glow light, gen2 light, and volt gauge started working again. This morning everything but the gp light worked. The glow plugs were how ever working the whole time. Then today everything quit again so I started looking at all the connections that might tie these together. I found this plug just to the left of the column and pulled it apart and plugged it back in a few times and instantly all is good. Now I even changed the card back out to the original one and it is working great. For now I will add some dielectric grease to the plug and see how it goes.

 

[MarcusOReallyus]

You might want to clean it up with some CRC Contact cleaner, then reassemble with dielectric grease.

 

[antennaclimber]

Thanks for updating us on finding the issue and a resolution.