My instrument gauges stopped working in my 1990 GMC Jimmy S15. What are my next steps to get it working again?

DAKOTAHSK

MEMBER
1990 GMC S15
290,000 MILES

After inspection I found that the fuse that goes to the gauges had blown. I replaced it to find it blew again and continually would blow when I turned the ignition on. The ignition switch and alternator have been replaced recently. I know there is a short somewhere but everywhere I look doesnt tell me whats on that circuit. Also at night when I have to turn on my lights the alarm that normally sounds when the car is turned off to alert me to turn the lights off stays on while the car is running. The alarm eventually kills my battery. Any ideas of where to look to solve this problem?

1 Reply

CARADIODOC

MECHANIC
33,874 POSTS

A simple trick to finding a short is to replace the blown fuse with a pair of spade terminals, then use small jumper wires to connect them to a 12 volt light bulb. A brake light bulb works well. When the circuit is live and the short is present, the bulb will be full brightness and hot so be sure it's not laying on the carpet or against a plastic door panel. Now you can unplug electrical connectors and move things around to see what makes the short go away. When it does, the bulb will get dim or go out.

Pull the instrument cluster to see if the short goes away.