Instrument cluster power lost

Krazykraut · Post by **Krazykraut** » Fri Aug 24, 2018 7:22 am

Here's an interesting one: a few days I noticed that some of the lights in my combination instrument did not light up when I first started the van: glow plug one of them. Also, tachometer, fuel gauge and temp gauge did not work. Gate lock light, signals, brake light all work.

So I hit the forums, and sure enough, it seems like this is a somewhat common problem: the connectors on the back of the cluster corrode and somewhere ground is lost. What is interesting is that as soon as the outside temp is above 25C, the lights and instruments work just fine. On my commute home, in 25+ C, all works. In the morning, or when it's colder than that, not so much. I don't think it's a moisture issue - we haven't had rain in months.

I pulled out the binnacle, unplugged the three round connectors and the square one, unhooked the speedo and hit all plugs and pins with contact cleaner. Reseated multiple times to scrape off oxide and put all back together. Still not working. So I guess I'll have to take it out one more time and use a screwdriver to tighten the contacts in the plugs. It would just help to know what I'm looking for. Or could it be a hairline crack in the printed circuit board?

So before I go and trace all wires to see where the missing ground is, I wanted to ask if somebody has seen this, and how did you fix it?

Not a major driveability problem for my commute right now, I know my hills and fuel level, but it needs to work come winter.

Post by **Growlerbearnz** » Fri Aug 24, 2018 1:55 pm

It could be a faulty earth or a faulty power line.

A faulty earth will cause you to not have any turn signal lights on the dashboard.

A faulty power line means you'll lose the 4WD, oil pressure, and battery/charge lights, but not the turn signals.

You're going to have to follow the traces on the back of the circuit board, figure out which one is power and which one is earth, and look for breaks in the circuit. As you've said, it's often corrosion on the plugs, but the pins on the circuit board can also move and break away from the traces.

Krazykraut · Post by **Krazykraut** » Fri Aug 24, 2018 6:02 pm

I'm fairly certain it is ground on A-13. Everything on A-16 works, and the only common thing that Oil, Fuel, Glow, F/GA and T/GA have in common is pin 7 on A-13. If I can trust the Supplement_1992_Electrical_Wiring, that is. Right now it works, as it was warm enough to make contact, will troubleshoot in the morning. I have my diagram printed out and power supply and multimeter ready.

Krazykraut · Post by **Krazykraut** » Wed Aug 29, 2018 7:50 am

Fixed. As I had suspected, cleaning up the connectors, a liberal application of contact cleaner to the pins and plugs and gently prying with a tiny screwdriver to re-tighten the contacts did the trick. Lit up like a christmas tree. While I was in there, I also checked all the little bulbs to make sure that they work.
Just for reference, attached picture of circuit board:

: combination_meter.jpg (467.18 KiB) Viewed 3040 times