electrical problem

I have an 86 and i can tell you from experince with it you may as well replace the wiring harness to get everything working because tapping into it to try and fix guages ignition or anything else like that will just blow up the whole thing and literally KILL your truck. anyway the wiring harnes isnt hard to replace its just finding one for the truck itself.

Same thing happened to my 86 pickup not too long ago. everything stopped working except the speedometer, but mine was just a fuse. it was the one labeled "meter and back-up lights" or "meter and [some kind of light]" I actually had a wiring problem that was cause this fuse to blow everytime i turned on my right turn signal. but if it's not the fuse i couldn't tell you the problem

I have the same problem my 92 and ive done a cluster swap and same thing no power to gas gauge temp gauge or tach no turn signals or blower ive had the whole harness gone over the fuses are fine and the 92 dont have a voltage regulator on the back of the cluster any help would really help guys ive been chasing my tail for a month now