What's This Plug For?

kirkRHughes · June 8, 2004

I had nothing better to do yesterday so I pulled the grill off my truck. There is a plug that goes to nothing, any one know what it could be for?

Also, when I was installing my fog lights, I noticed some wires under the fuse block that were not connected. They were fairly heavy gauge wires and looked like they should go to the positive post on the back right of the block. Then they go down under the truck. Could they be for some kind of towing set up?

The picture for the plug is on my webshots page, I haven't figured out the right way to insert it into the post yet

http://nikitathedog.photosite.com/plug/

Thanks for the link AZ-Z71

AZ-Z71 · June 8, 2004

Problem with your picture link, it tells me I'm not the owner of the album.

Not seeing the plug, are you talking about something that looks like a house plug?

If your truck is a diesel it could be for the block heater.

kirkRHughes · June 8, 2004

SteveCZ · June 8, 2004

still no dice with the picture

AZ-Z71 · June 8, 2004

Still a problem with the link. Sorry.

kirkRHughes · June 8, 2004

Well, it looks like I just can't get it right, one last try

http://community.webshots.com/scripts/edit...security=TxneHW

AZ-Z71 · June 8, 2004

S O R R Y!

Here why don't you try to e-mail me the picture. I'll link it to my site for ya.

Check your PM for my e-mail address.

AZ-Z71 · June 8, 2004

Here is the link to the photo.

Truck is a 03, 1500, 4.8

What is this Plug

Is it maybe something for a plow package??

blue2kzr2 · June 8, 2004

Do you have an overhead console with a temp. display? If not, I suspect it's a plug for the temp. sensor that's non-existant. My FSM info doesn't go as far as '03, so I can't look it up there...

kirkRHughes · June 8, 2004

I have the self dimming mirror with the temp/compas in it. If I have time today after work I'll try to trace where it goes and see if it has any juice going to it.

GMCTech · June 8, 2004

Your picture is of the ambient air temp sensor, and it's connector.

There is another plug in that harness that will plug into that sensor, but I am also not sure what it goes to. Possibly a light dimmer sensor or another temp sensor for something.

Sorry I couldn't be more help.

citydriver · June 9, 2004

kirkRHughes Posted: Jun 8 2004, 07:43 AM

I noticed some wires under the fuse block that were not connected. They were fairly heavy gauge wires and looked like they should go to the positive post on the back right of the block. Then they go down under the truck. Could they be for some kind of towing set up?

If 1 of these wires is ORANGE and the other is BLUE...Yes they should be for the trailer harness...the orange line is usually for the +12v /BATT line and the blue line is for the ELECTRIC TRAILER BRAKES when hooked up to an electric brake controller(aftermarket)....If you have a Haynes repair manual,they have the basic wiring diagram for the set-up.....p.s. I used mine to hook up aux. lights in the rear...

99GMCZ71 · June 10, 2004

It looks like the temp sensor for the mirror. When it is unplugged, check your mirror temp it will have lines like this --- if I remember right. If not, then my best guess is the temp sensor for the auto A/C if you have that option.

kirkRHughes · June 10, 2004

We have an 03 base 1500 and an 04 base 3500 here at work and neither had that plug so it may be for the mirror temp, I'll unplug it today and see.

I like the idea of using the the trailer wires for rear light, thanks.

I noticed on our 3500 that it had a trans cooler on it, I wonder how much that set up would cost from the dealer?

kirkRHughes · June 10, 2004

Looks like 99GMCZ71 was right, it's the temp sensor for the mirror. I just unplugged it, the one on the left is with it unplugged, the right is plugged in.

Thanks for everyones help