Which wire sends power to the fog light relay from the headlight switch? And does the factory headlight switch on a 97 without foglights have the innards to switch foglights on and off? Mine clicks when you pull out on it...

 

I can't figure out which wire activates the fog lights.

 

Still having problems with this ??

The link in Bob's thread had the wiring diagram.

One thing to look at closely is the pin numbers on the switch.

The P.O might have installed the switch, and the pins are not populated with the connectors.
If this is the case, either getting a light switch harness from the bone yard, or trying to find them at NAPA, so you can add them to the connector.

The thread on adding Power Folding Mirrors ( forget the member that did this ) has some good directions on pulling the connectors out of one harness and installing them in a new one.

Let me know which way it is.

Later Bro, I need to try to get 5 hours of sleep

Steve

 

Look for a red/yel out of the switch to the multifunction.
Red/blk from the multifunction to the fuse .
Wht/blk from fuse to the relay winding.

 

What are you refering to as the multifunction? What is a relay winding?

All I want to know is, Which wires are associated with the fog lamps?
Which wires do I need to tap/cut/etc to run an accessory off the fog lamp switch?

 

In the main headlamp switch is there :

1. A yellow wire ?
2. A White with a Black stripe wire ?
3. a Black wire ?

If the previous owner ( PO ) installed a '99 or older switch

This is the diagram from the 1999 EVTM



In this case, the yellow wire is going to have a ground signal on it, so you would need to put a relay inbetween the strobe light controller, and have the power side of the coil hooked up at all time, and the ground side of the coil, go to the fog lamp switch.
WH-BK on pin 15.
YE on pin 3
BK on pin 4

If the previous owner ( PO ) installed a '00 to '03 or switch

This is the diagram from the 2001 EVTM



In this case, the yellow wire is going to have what ever is on the white with a black stripe wire. This should be power from Fuse # 27. In this case, you can power up to 5 AMPs from the switch itself, any thing over this, use a relay.
WH-BK on pin 2
YE on pin 5
BK on pin 6

When you pull the headlamp switch out, take a look for the wires above, they may or may not be there, depending on how far the PO made it with the install. In the '98 and older truck, independant of the trim level, the harness was not always complete like it is on the '00 and newer trucks ( i.e. XLt has the same harness as the Lariat ).

In both cases the output of the fog lamp switch is the yellow wire ( again, if installed in the connector ) and depending on what year switch, is if you are going to get ground or power on it.

You need to take a look at the pins on the switch, to see which it is, I would guess it to be a '99 and older switch, so the first part of the post, is what you should be using.

Let us know if that explains it correctly.

 

Thanks! I'll try it this evening.

 

I took a multitester and tested the yellow wire..... When the lights were off, the yellow wire showed an open circuit. When the light switch was turned on, the yellow wire showed 12volts. When the foglights were activated(pulled the switch out) the yellow wire still showed 12 volts. So, I don't think the yellow wire is related to the foglights. Any other suggestions?

 

Steve, I went ahead and took my switch apart. It doesn't have the mechanism to activate the fog lamps in it. Thanks anyway!!!