Hi, I have MK3 86.5 non-turbo and i tried 2 dimmer switch replacements... and nothing... my dash lights and tail-lights didnt work. I let it go so long that a CHP gave me a fix it ticket.
I finally gave up and took to a mechanic... electrical... $240 later... and works perfect now... i also use the dimmer... just so that it wont go bad again....
I still had to pay the friggin ticket "Bail Amount" is what they called it... $165. UGH... did that hurt when i bought the money order and mailed the darn thing....
so my advice.. if your driving it. Check all the lights Headlights... Tail-lights also... cuz it might not be just the dashlights.... and it will cost you more than just a dimmer switch...

