Ignition Wire Identification

[KBertetto]

I need some help. I have a new Optix EGT gauge, and I need to locate a wire off of the ignition that has constant power once the ignition is turned to the ACC or Start position. I know the colors of the wires change fairly often as they build these trucks, mine is an 04½ built in March of 2004. Any advice is appreciated.



Bert

 

[SShafranko]

You can tap into the cigarrete lighter wire. A better place is to tap into the light switch wiring and at the same time you can tap into the dimmer wire so that you can dim the gauges with the rest of the dash lights. Check the wires with a test light.

 

[KBertetto]

I already tapped the dimmer wire for the gauge lights, but didn't want to tap again off the light switch as these switches have been known to melt down. I will try the cig lighter, thats a good idea, but mine is constant power to the one in the dash, even when the key is off. Is there a way to make it only have power with the key on?

 

[DaveHess]

Hey Bert. Mine is an 03. 5 so hopefully ours are the same. I went to the Power Distribution Center (PDC) that is located in front of your drivers side battery. Once you take the lid off, and after turning the ignition switch to the ON position, I used a test light and probed all the empty sockets located in what would be the front section of the PDC. Once I found one, I turned the ignition switch off and confirmed that the 12vdc went away. I wish I could tell you the exact position I used but unfortunately mine is at home dead in the water with a fuel leak. Incidently, I purchased a higher quality fork type crimp-on connector. It fit perfectly into the slot where I had found 12vdc switched power (ignition on). I ran that wire through the firewall to a Painless Wiring Auxillary Fuse Block to power (trigger) the relay. All of my accessories now are powered from the fuse block. Much cleaner set up. Hope that helps. BTW, I am retired USAF. 20 years, 3 months and 9 days of service. Left in 2003 but would still be there today if my bride hadn't decided I had enough! She followed me for 16 years so I figured it was her turn for me to follow her.