I have an 99 SR5 4X4 auto without locking diff or fog lights. I was working on the dash last weekend and found two wiring harnesses behind the dummy plates just to the left of the dimmer switch for the dash lights. Anyone know what these harnesses are for? I was thinking that one would be for fog lights but was told that the fog light wiring termintes in the steering column and plugs into a different stalk, the one with the controls for the fogs on it like on the limiteds.

 

Yes one is for the fog lights, if you look where your fog light would be if you had them there is also a wiring harness there (on the front valance). SR5 models came wired for fog lights while base models did not. As for the locking rear diff I don't have the knowledge to tell you.

 

One may be for the locking rear diff switch, my 2000 had it pre-wired.

Check this write up: http://www.sonoransteel.com/phong/re...ic_locker.html

 

I was behind my dash this weekend and saw the same two plugs. I do not have fog lights, so my guess is one of those harness plugs was for the factory fogs. But I do have the factory diff lock, the clutch start cancel button and the factory alarm, so I have no idea what the second plug could possibly be...
I think the 5-speed trucks with the alarm and diff lock are the only ones to come from the factory with all the dash switch knock-outs filled.

 

Hmm yes I know that it is wired for fogs but I was told the SR5 with fogs would have the same headlight stalk as a limited and the wiring terms in the steering column. Soooooo do the SR5s that came with fogs have a dash switch or stalk switch? I have been told 2 different things.

 

If the fogs were "port installed" there will be a switch on the dash. Most fog lights were factory-installed and thus have the switch on the left-hand stalk.

 

i remember reading somewhere that one of them is for the power mirror switch if you have manual windows (base model).

 

The ECU for the factory diff lock is located below the fuse box under a plastic cover. Look there for an unused connector. Here is what it looks like (see the forward box.) Just FYI--ignore the white label and the physical location of the ECU--this was a custom install in my '94 pickup.