the other day i picked up a 88 irock and on my home i noticed that i the tach was maxed out at 7k no temp gauge either .all the rest of the gauges worked well also the brake lights didn't work ... so today i replaced the brake/hazard fuse and the lights now work but wen i hold down the brake the tach drops back down to 4500 not sure what to make of it any thought would be helpful .

 

Hi Jerry ,

One of the first things I do on any new to me car that is having electrical issues is to remove any and all aftermarket devices (alarm systems , aftermarket radios , etc) and put all the wiring back to it's factory supplied configuration . Then I start with the troubleshooting . If I had to throw out a wild guess I'd say it sounds like a grounding issue in the dash when something as unrelated as the brake lights coming on will cause a change in tachometer readings .

PS , you now own an "IROC" , as in "International Race Of Champions" (the basis of the "IROC" name) and not an "irock" , as in "Dude , I rock !" . You and you car may very well rock , but music has no basis in the "IROC" name