e30 rewiring

[icecube76]

i bought 1990 mtech e30 with m50 upgrade
the car was auto and has been converted to manual.
the previous owner did a bad job with wiring
the engine runs fine ,
RPM not stable when idle.
temp gauge not working
check engine blinking.
most of the warning control panels lights are on, overheat,brake lights,rear lights,low beam , washer fluid, license plate light and engine oil.
how to repair that? should i just replace the engine harness with stock e30 and use an adaptor for the engine ?
help appreciated.

[george graves]

Eeek man, that's a tough thing.

If your're not willing to dig into the etk, you're going to have to send it to someone to fix it.