1ok so i just recently had a problem with my instrument cluster lights being on all the time. I found the problem; it was the aftermarket radio the guy wired wrong. So i rewired it and then the lights on the gauges were finally off. .

Then i found that when i turn my headlights on my taillights and instrument cluster lights didn't come on.
I checked the fuses and they are fine. I changed the headlight switch a very long time ago. 1985 z28 Please help.

 

So it was a botched radio install that had the lights on all the time , very well , I'm glad I called that one right . Now , if a test light shows power on both sides of the taillights fuse , the next thing would be to check the solid orange wire going to the switch for power . If it's got power there , turn the switch on and check the brown wire for power . No power at the brown wire , with power on the orange wire and the switch turned on , would mean that the switch has lost it's parking light contact . The switch contact could have gotten fried depending on how bad the radio miswiring was . If you DO have power at the solid brown wire with the switch on then it would have to be an open wire in the harness somewhere between the switch and where the circuit "splits off" to feed the different lights that run from that circuit (front running lights , rear running lights , side marker lights , and the dashboard lights after passing through the "inst" fuse .)

So pop that switch out , get with that test light , and post back what ya find

 

I found an orange wire on the harness that the guy had wire with two yellow wires and that made the gauge lights and taillights work but i have no control on turning the cluster lights on and off..sounds crazy but its true

 

Hi Patrick ,

I would really like to help you , but the problem is that since someone has been into the wires , and it sounds from what you've already found that the previous "work" was actually butchered , it is impossible to know in what ways the wiring was screwed with . Sure , I can give ya all kinds of troubleshooting tips on an unbutchered harness , but once some joker has been at it likely with scissors and a "Forest Gump" knowledge of automotive wiring , all bets are off as to what is wrong being found easily . Were this mine to troubleshoot , I'd start by using the wiring diagram and repairing every bit of wiring that shows evidence of being tampered with . Once the harness has been restored back to 100% stock condition , the troubleshooting should be a piece O cake .

Where to get the wiring diagrams for your car , you ask ? Well , there is a site called austinthirdgen that I will attempt to link to , and this site has all the diagrams you'll need to properly repair your harness .

www.austinthirdgen.org/index.php?pid=19