wiring gauges

[Burning Pyro]

i didnt even have the car on and they still lit up with both wires. the yare supposed to start when the key is turned, otherwise right now they stay on 24/7 no matter what. i knoq in gm vehicls that the ignition line is purple...but yet again thats GM

[cre]

12v lighting - Dimmer harness, the solid green wire.
ground - Chassis or the white with black stripe wire on the dimmer harness.
12v ignition - Defroster harness, the solid yellow wire. (Ugh, I can't remember if this line is run through the headlight switch or not. If your car is pre89 use the Black wire with a red stripe that runs to the cruise control switch. Otherwise, test the yellow one to see if there's power there when the lights are off.)

References:
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=100
http://www.cygnusx1.net/Supra/Librar...x?S=Main&P=084

[abhattan]

In a case like that, I would make up a little harness for all three and run the harness from the gauges down to the ignition switch and dimmer switch. Sounds like a lot of work, but it's really not. This way, you could have proper function of the gauges as well as not potentially messing with another electrical system. These cars are sensitive when it comes to the electrical system.