hoopdaddy6

Whats it called, how much does it cost? Why does the jeep loose all power whatsoever (I mean, ALL power) when there's not a jumper wire connecting it to the battery?

Bad wiring, or bad "thingy"?

BlueXJ

It is refered to as the power control module or PCM. It routes most of the vehicles power for essential things through it. Thus the power loss when it is unpowered.

dangerousdavid

lol...thingy!!!

captainwoot

isn't that the starter relay on renix models? it also is a connection point for fusible links to power other circuits?

Abovetimberline

yes that is correct,and when it goes so does your power,I carry a spare.

BlueXJ

Yeah all the large leads with a rubber looking sleeve are fusible links and I have always heard it called a PCM. May not be the proper name for it.

Abovetimberline

it cost anywhere from $40 to $70 depending on brand.

4.3L XJ

Blue. I have always heard it called starter relay, since that is what it is.

Mike1998XJ

Is it safe to assume it's bad so someone jumpered it to the battery. Like the old trick of starting the car by touching two screwdrivers across it with the key on?
Mike

4.3L XJ

Mike

That post is supposed to be hot. Generally there is at least a 10 gage wire from the positive terminal of the battery to that post. If he is having trouble with it, that little wire is suspect in my book. The power is supposed to go there and then through the fusible links to the dash area. That relay also runs the starter solenoid so there is not excessive power running through the ignition switch.

Mike1998XJ

Steve:
Yep, then someone cobbled that blue wire in there. I would start with that also. Looks like someone made a change with good intentions but the execution wasn't so good...
Mike

ol"blue

I would check those wires going to it. They look a little funky in the photo. JMO