'88 electrical problems

[Bill Siver]

I recently installed a fresh 6.2 in my '88 and I have since been plagued with electrical problems when the truck never had problems before. First, I am pretty sure all the grounds are good. That was my first move. Ok, the glowplug controller wasn't getting signal power, the heater fuse pops as soon as you turn the ignition on, the brake light is always on (but dimmer than if I apply the E-Brake), the speedo doesn't work(or spins crazily), I don't think the fuel gauge is working (it reads full, but I think I have 3/4 of a tank).

BUT...the temp gauge works, the volt meter works, the lights all work etc.

Any idea what would tie all these things to the same problem?

Thanks,

Bill

[Uncle Wally]

hmmmm.

I would check the ground under the dash. But unless you disturbed it, I couldn't see how that would be an issue. If all grounds are good, I would look at the harness behind the drivers side cylinder head to make sure it didn't get pinched.


I've has two odd experiences on my 90's trucks. I did some work under the dash on my 94 and pinched the harness by mistake. Almost everything acted funny, but I didn't realize it was serious until smoke started rolling out from under it the dash. I found the issue when I pulled the whole dash apart. On my 90 I had a nut come loose on the junction panel on the passenger side firewall. It took me 3 weeks to figure out that a loose connection on the junction block caused the fusible link that powers the pcm to burn out.

Probably not that much help to you other than to expect anything.

Waldo