1999 Limited mysterious plug

[ambush]

Hello all

I am back! I just bought a 1999 Limited with 166k miles on it for a VERY good deal this past Friday. The previous owner decided not to take good care of it so I took it off their hands So far it drives well and cosmetically needs attention but there seems to be some weird stuff going on electrically. The windows, sunroof, door locks and horn do not work. I think I know what it is. Junction box maybe? It looks as if they tried to install a stereo or something. Anyway, upon investigating, I found a plug under the fuse box area (driver's side foot) that was not plugged into to anything. I don't recall an extra plug on my previous 3rd gen just hanging (looks like a rats nest here). Can anyone help me identify this?

Many thanks!

Ambush

 

[TheDurk]

If you want a plug identified, shoot it end on so we can count pins. If that is 4 on top, and 6 on the bottom, it is likely Plug D29 that goes into the Rear Diff Lock ECU, which I am betting you don't have so it just sits there.

I can confirm if I could see the wire colors, but I can't see those either.

 

[pavelvoivoda]

This should be where the rear diff lock ECU plugs into the wiring harness.

You should also have another plug up left of the steering wheel, hidden behind the dash.
If you plug the OEM RR diff lock switch in that plug, and RR Diff Lock ECU in the one in your picture, an icon should start blinking on your speedometer lower right, indicating that the RR diff lock has not engaged correctly or in your case - it ain't there at all.

If it lights up steady tho... then you win the record for shortest rear diff lock install on the forum!

I found a plug under the fuse box area (driver's side foot) that was not plugged into to anything.