Yeah, I know what you mean! The previous owner of my current car had an Alpine HU put in and whoever did the install CUT out the factory harness! I was horrified!!! Anyways I used a voltmeter and tested each wire one by one to find the dimmer, but in retrospect it would have been easier to have just looked it up in my Haynes manual.
I think the dimmer wire on a 94 LE is the Red/Yellow wire. At least that's what my old 1982-1994 Haynes repair guide says. Honest Bob, hope this helps!
Gone to a better place...
