I installed pillar mount- Autometer guages in my 2001 F-250 Super Duty diesel. Can't seem to find WHICH wire to tap into for proper guage lighting.
Can anyone help?
Thanks,
Marshall

 

Any wire that's hot with the headlight switch will work. I ran a tap down the pillar from the left most cab marker light. Lots of folks just use the spare wire from the brake controller harness pigtail.

Neither of those will allow you to dim the lights, but my insturment cluster lights are always all the way up anyways.

 

Sorry, just read your other post. If I'm reading this schematic correctly the wire from the dimmer switch to the dash bulbs is Light Blue with a red tracer.

 

I took the headlight switch assembly out, and used a test light to find the wire that controlled the dimming of the lights. It was very quick and easy. Then I tapped into that wire and it worked perfectly.

 

I have a 2002 7.3 and recently installed gauges. I popped the headlight module out and metered the dimmer portion of the module and found the blue wire with the red stripe that was the dimmer for the stock gauges.
I "T" tapped the wire and terminated the Auotmeter positive leads for the bulb lights to that wire.
Works fine.
Helps to have a meter, wiring color codes may be different for different years.
Use a bent paper clip to insert into the connector when probing for the correct wire.

 

How do you get the headlight assembly out? I tried putting a screwdriver in the slot at the bottom but it didn't want to pop out.

 

On mine, there is a very small rectangular notch at the base of the dimmer/head light module. Insert your driver and twist it sideways or push down and the module pops out.

 

Pop the big fuse panel cover off and under the dash to the right of the steering wheel there is a 6 wire connector, possibly an 8 wire but only 6 are used. Regardless of wire color, the top center wire of this connector is controlled by the dimmer. A voltmeter will confirm this. It's easy to access, and easy to tap. I assume that you already installed the gauges, but if not it's also easier to daisy chain all the light wiring so that you only have 2 to deal with when tapping in to the vehicle wiring. Hope I'm not too late to help!