What is this wire behind front bumper?

[robfg67]

I have a 1990 MJ.

 

 

[Pete M]

fog light harness?

[robfg67]

If so, wouldn't there be two pigtails?

[Pete M]

not out of the main harness.  only need pos and neg and the fog light harness would have the split in it.  I am just guessing though, but not much else that would be in that spot.  I can check the trucks in the morning if no one chimes in sooner. 

[fiatslug87]

To me it looks like the temperature sensor plug found in XJs.

 

Aren’t fog light plugs weatherpack?

[The86manche]

6 minutes ago, fiatslug87 said:

To me it looks like the temperature sensor plug found in XJs.

 

Aren’t fog light plugs weatherpack?

That's my guess too 

[pizzaman09]

Indeed the fog light plug is a weather pack on my 90.  I was wondering this too, I also have that random plug behind the front bumper.

[robfg67]

Is there a factory diagram that shows it?

[87MJTIM]

10 hours ago, fiatslug87 said:

To me it looks like the temperature sensor plug found in XJs.

 

Aren’t fog light plugs weatherpack?

 

+2

 

What are the wire colors?

[Gjeep]

Overhead console temp sensor. That's XJ wiring you have up there.

[JZLAJeep]

2 hours ago, Gjeep said:

Overhead console temp sensor. That's XJ wiring you have up there.

Interesting. Now we know. We recently replaced the headlight wiring harness (twice) on our MJ and had this plug too thinking it was fog lights too based on it's location. The plug just dangles unused every time we've seen it.

[schardein]

These are screenshots from the 1991 FSM.  My guess would be the temp sensor for the overhead console.  Second pic shows the fog lights connections.

[Pete M]

so the fogs DO split off inside the main harness first.  good to know! 

[JZLAJeep]

52 minutes ago, schardein said:

These are screenshots from the 1991 FSM.  My guess would be the temp sensor for the overhead console.  Second pic shows the fog lights connections.

Interesting to see where the wiring harness for the headlights is supposed to be. Ours just lays on top of the bumper, probably as a result of all of the clips being broken. 

[robfg67]

If, in fact, that is a temperature sensor for an XJ-something never offered in an MJ, I wonder if it was a mistake on the assembly line.

[robfg67]

I'll have the bumper off tomorrow to add fog lights, so I can report back the colors of the wire.

[schardein]

48 minutes ago, robfg67 said:

If, in fact, that is a temperature sensor for an XJ-something never offered in an MJ, I wonder if it was a mistake on the assembly line.

I'm not certain that those wires were never present on an MJ.  Perhaps it's true for early models.  There were some changes in 1990, for instance, I think that was the year when they were no longer pre-wired for the bed cargo light.  Earlier models were all pre-wired for it.  It stopped in 90 I think.  I know my 91 isn't wire for a cargo light.

 

As I've gotten older, my memory has started to slip a little.  But I want to say that my 91 has a plug near the windshield washer bottle for a rear window washer pump, something an MJ never had.

[robfg67]

Yeah, my '90 didn't have the wires for the cargo lamp, but did have the dash wires for the fog, even though the truck wasn't ordered with either.

[87MJTIM]

If yours is a '90 (last of the AMC era electrics/RENIX) and the wiring diagram is a for a '91 (first year of HO), was the wiring changed/altered that you know of?  If 'No', then I doubt the connector is for an outside temp. sensor (something an MJ never had).

[fiatslug87]

My ‘90 also has that connector, but my ‘89 and ‘88 don’t. ‘90 was a transitional model year, for example the knee panel courtesy light connectors changed and are the same as ‘91 on.

[eaglescout526]

6 hours ago, robfg67 said:

dash wires for the fog

They all have them. You won’t find an XJ or MJ without the connector and wiring. It’s pretty easy to put in fog lamps using the factory wiring to the switch. 

[robfg67]

The connector has an orange with green tracer wire and a light brown with a blue tracer wire.

[schardein]

Found the air temp sensor connection in the overhead console wiring diagram.  This is for a 91.  The wire colors don't match but that doesn't surprise me. 

I found a reference to an air temp sensor in the 88 MJ wiring manual, and it had a orange/green wire, but I couldn't find anything in the schematics- probably because it wasn't an option, the fact it was even mentioned was probably a "copy and paste" from the XJ wiring manual.

[eaglescout526]

Wait. Didn’t the 90 XJ have an overhead console in the limited and Wagoneer limited trims that had a temp readout for the outside temp? 

[Minuit]

Outside air temp sensor. That's the only thing in that area that uses the Chrysler Wedgelock connector. I have spotted part of the wiring for it on my 91 as well. Can't remember if it goes all the way down to the mounting location as seen here.

 

It was offered on higher trim XJs starting in 1990.

 

There are lots of unused connectors such as this for XJ only features. Can make your life easier if you ever want to add that.