RocketMouse

I have an issue with my power windows on my 99 XJ.
I've been trying to track down an electrical gremlin.....
With my multi-meter I've discovered the following so far....
The wiring from the connector at the window/door actuator switch tests perfect, no resistance from the connector at the panel switch and at the connector that connects to the power window motor in the door.
So that tells me that there's no break/short in the wiring.
What I HAVE found and please tell me if I'm wrong... but I tested both pins at the connector that goes directly to the window motor... and was seeing approx. 4.5- 5 Ohms resistance.
When the wires to the control panel were 0.00- 0.01 Ohms. So I'd say that's a good result.
Am I smoking crack? Or am I on the right track here. I don't want to load the parts cannon but seems to me that I need to replace the window motor/regulator.

When I had it connected as it should be, without touching anything else.... the motor housing would start heating up crazy hot within seconds.
Now after my troubleshooting steps... I can have the panel connected (without the motor/regulator connected) and no heat from resistance... so unless I'm completely stupid... that tells me that I may have narrowed it down to being the motor that needs to be replaced.

I'm open to recommendations from anyone that is familiar with electrical on these puppies.
Thanks.

Roler

But what is the issue with the windows?
or is that the issue, the motor heating up?

I've had that doorpanel apart for various things more often than I've done oil changes on that thing - ended up getting a new motor assembly after I got tired of the fixes here and there.

If things heat up it means there is current flowing through high resistance. If that occurs while you are not even operating/trying to operate the window motor, I'd say you have an issue with a continuous live wire/current draw

RocketMouse

Yes Roler... the motor heats up like nobody's business within seconds if everything is connected as it should be.
I've done testing from the connector from that point to the control panel with my meter and the continuity from connector to the panel.... and no open loop.. a perfect closed loop with nearly 0 resistance.
But when it's plugged into the connector that goes to the motor/regulator... it heats up to the point that I think it's going to melt within seconds.
I just wasn't sure if there should be that much resistance at the connector to the motor/regulator.

I can rebuild a motor no problem... but I know a little bit of electrical.... and to me I don't think there should be that much resistance going through the motor/regulator with no power to it.

Jim Malcolm

The Mopar replacement I've been running for a few years measures 2.3 ohms.

Try tightening up the female terminals in the wiring harness connector. They may not be making good contact with the blade terminals on the motor. Real quick, off the top of my head math, 5 ohms doesn't seem like enough resistance to be heating up to the degree you're talking. And one would think the heat would be in the motor, not the connector.

Are you measuring 5 ohms on the terminals on the motor directly or are back-probing the connector?

awg

the next step is to run the motor direct with 12V, using the vehicles battery, or another, just run a couple of leads, wire a switch in is best

Test motor, see if it gets too hot

RocketMouse

@Jim Malcolm ... to answer your question I tested the terminals at the connector that goes directly to the motor/regulator. The assembly is still mounted inside the door.
Everything downstream from it, i.e. the other side of that connector that goes to the "control panel" (with the window/door switches) that wiring measures perfect indicating no issue.
The heating up issue from resistance (I think it's safe to assume)... only happens when I plug in the in-line connector that provides power to the motor/regulator assembly.
I can leave the connectors plugged into the "control panel" and the power locks work just fine, and that panel does NOT get hot either.
So I'd say I've either got a bad motor/regulator and/or is it possible that 1 or both of those pins in the "control panel's" circuit-board fried? Not sure how to test that possibility.

Jim Malcolm

Heat occurs at the point causing the resistance. Some may get transferred away, but the hottest point is where it's occurring.

In your first post, you say "When I had it connected as it should be, without touching anything else.... the motor housing would start heating up crazy hot within seconds." Are you hitting the button or literally touching nothing else? If current is flowing without pushing the button, you have problems in the switch(s). I know nothing about the newer models unfortunately.

In your last post you say, "only happens when I plug in the in-line connector". You need to have a complete circuit for electricity to flow so that is to be expected...

But back to point one, follow the heat..

MrTodd

When I was having trouble with my 1999 rear passenger window, I followed the troubleshooting method and schematic as found in the 1999 Jeep Cherokee Factory Service Manual. I did not ohm any circuits out as I found checking for continuity to be the better option. I uploaded my progress and findings to youtube. Hope this helps!

Todd

https://youtu.be/aW4jhNqdywM?si=Ysh4q2N3tvlxVBlY

RocketMouse

Thanks for all the help.... I will take the door card off soon as I can for another definitive test. I don't want to say something that is inaccurate.

RocketMouse

Ya'll gotta see this one.... I hadn't had the chance to get at the Jeep again for about a week or so... (it doesn't get driven every day)....
Well it was in the same state that I left it which is this:

Driver's side door - window motor is disconnected at the window motor (the plug that sits inside the door)
The control switch is plugged in.
Initially when I did this at the time of my last post to this thread - the power door locks all worked again but none of the windows worked.
I get in my Jeep yesterday... and now for some reason.... the power door locks don't work, but now the windows do (not the driver's obviously)
Could I just have a bad control switch?
I did test for resistance before and the wires that went to the motor confirmed they were all intact.

lawsoncl

It's common for the window control switch panel to develop bad solder joints, which can be resoldered. Frayed and broken wires in the drivers door between the frame and the door are common as well.

RocketMouse

Yeah... I hope it's the switch panel... If it's the bundle that goes through the door into the jeep... may not have enough time to mess with that.

Tobylblack

Its a Jeep, there are no quick electrical questions

IJM

It could be worse. It could be British.

awg

My 55yr old Jaguar has better wiring than my 27yr old Jeep

@ the OP, made investigations of why I had a window problem on my spare '96, everything tested with continuity

I made a piggy back jumper wire that bridged the main wire I suspected (which I think is the one going to the switch, pretty sure it sourced behind the kick panel)

fixed !

very peculiar as the jumper wire is only 5 amp gauge, I assume the contacts or main wire have high resistance when significant current is drawn

A multimeter will usually not detect faults like that