I have a 90 rex with B16 and I hooked up a amp and after about 15 miles 17 popped up and my temp guage bounces up and down head lights dim and radio cuts out every time I hit the brake and with the head lights on the tac spikes even after I took the amp out I had the ground for the amp hooked up at the same spot as the tail light ground and after problem started I moved the ground also had the power wire running by the ECU and took everything out and same problem.any info helpful

 

Any guess would be helpful

 

Where and how did you hook up the power for the amp?

 

Had this same problem in a 86 celica the wire at the battery was loose. Tightened everything down and everything was working again. Just my .02 cents

 

code 17 is speed sensor code, but thats not all your problems. try checking the ground at the thermostat housing. have seen a lot of problems there.just a suggestion. good luck.

 

The tach, temp guage, and speed sensor are on the same fuse (#1 dash). I would check this circuit and definitely check the thermostat ground. Does your clock work?

 

Yes the clock works but go`s out when I turn the lights on and then comes back on.
where is the thermostat ground,my guess is that your talking about the temp sensor.

 

anything else wuold be helpful

 

The thermostat ground is right at the thermostat housing- one 10mm head bolt with a bunch of wires going to it- remove it, clean it, reinstall.

 

OK,I cleaned the ground and still same thing

 

OK,next

 

you are drawing too much current that would cause the problems you are experiencing. try a slightly larger alt or battery or both. you may want to put some caps on your amp to use as reseve power 1 farad is about right at 20V