Accidentally supplied 24V to 95 XJ

[Hypoid]

Did all the other problems go away?

 

[CorneliusRox]

Did all the other problems go away?

Yup. I've gotten everything else cleared up.
I use cruise control every day into work since I'm about 40 miles of expressway away, and I definitely used it on the morning before the 24V thing.

Is there a way to test the diaphragm? I'm not sure how that would have gotten fried since it's based off vacuum though.

 

[90xj06]

it does have an electronic side to the servo under the hood.

 

[CorneliusRox]

it does have an electronic side to the servo under the hood.

:banghead: Yeah, I'm not sure what I was thinking.

I'll ohm it out and see what she looks like. Thanks for the 100th time! ha ha

 

[CorneliusRox]

I've got vacuum, but didn't have time to Ohm everything out. I am borrowing some Fluke tools from my buddy (cool pins that go into wire insulation without harming it), and it should make checking the wiring harness go much smoother.

 

[Green Mesa XJ]

Not sure if the PCM comes in to play, I'm sure something is sending a signal somewhere. In my experience with Cruise control is in replacing the servos assembly in the engine bay or the control on the steering wheel. Usually one or the other fails because of heat in the engine bay or abuse from the drive toggling switches .
Jeeps have been good to us no issues with the cruise control .
But you'll probably know where the problem is when you test it out.

PS apparently from what I've read the cocksprings come with and without cruise control.


Sent from my iPhone using Tapatalk

 

[CorneliusRox]

Not sure if the PCM comes in to play, I'm sure something is sending a signal somewhere. In my experience with Cruise control is in replacing the servos assembly in the engine bay or the control on the steering wheel. Usually one or the other fails because of heat in the engine bay or abuse from the drive toggling switches .
Jeeps have been good to us no issues with the cruise control .
But you'll probably know where the problem is when you test it out.

Yeah, I need to test the servo yet. I know I read how somewhere in the service manual but am having a hard time finding it again. And last night I didn't get to work on the Jeep because the wife and I went out to a nice dinner.
Thanks for the advice. I hope you're right. I'd love to swap out one of those two components over taking wiring harnesses apart or buying a new PCM...

PS apparently from what I've read the cocksprings come with and without cruise control.

That is true. I made sure to get the one with. Basically, the one without on the 95 XJ's is only a single wire for the horn! Mine came with the horn wire and the four pin connector for cruise.

 

[Green Mesa XJ]

I've no experience with the 95 up cruise controls, when it the basic hardware it usually a simple failing.
When I read up on the 95 I was surprised the clock spring played such a important part, makes sense when you think about it.
Other part I'd look at is the brake switch, if we assume the clocksprimg is good, and kind of give the Benefit of the doubt to the to the servo and switch in the column, the next big culprits are the brake switch sending a bad signal so the Cruise control never engages.
I kind of doubt it's the pcm cause everything else works. But..


Sent from my iPhone using Tapatalk

 

[CorneliusRox]

I've no experience with the 95 up cruise controls, when it the basic hardware it usually a simple failing.
When I read up on the 95 I was surprised the clock spring played such a important part, makes sense when you think about it.
Other part I'd look at is the brake switch, if we assume the clocksprimg is good, and kind of give the Benefit of the doubt to the to the servo and switch in the column, the next big culprits are the brake switch sending a bad signal so the Cruise control never engages.
I kind of doubt it's the pcm cause everything else works. But..

I'm also leaning towards it not being the PCM.
So my brake lights work, and in my mind that meant that this shouldn't be an issue. I could try pulling the plug on the back on the way home to see if that helps at all.

Just for reference, I finally found the PN for the servo.
PN: 04669979
Looks like they go for $70 minimum, so hopefully it's not that.

 

[Green Mesa XJ]

Brake lights can work and the switch still be bad. Although it's probably not likely.

The xj 91-96(?) controls several things besides the lights, cruise control and the torque converter lock and unlocking. When they do go bad it can be a pain to trace all that back to the switch. (It's got something like 6 wires going to it)

I'm going to check if I have a FSM for the 95-96 XJ. I'd almost like to believe there's a in line fuse someplace since everything else is working




Sent from my iPhone using Tapatalk

 

[CorneliusRox]

Brake lights can work and the switch still be bad. Although it's probably not likely.

The xj 91-96(?) controls several things besides the lights, cruise control and the torque converter lock and unlocking. When they do go bad it can be a pain to trace all that back to the switch. (It's got something like 6 wires going to it)

I'm going to check if I have a FSM for the 95-96 XJ. I'd almost like to believe there's a in line fuse someplace since everything else is working

I've looked all over for an in-line fuse, but haven't found one. I feel like it should be fused somewhere.

Also, I can confirm that both my brake lights and my TC lock-up work. I'll still try unplugging the cable and seeing if anything changes.

 

[Green Mesa XJ]

If that part number for the servo is correct I'd hit a junk yard or eBay, it the same for dozens of vehicles even our 06 commander.
Liberty, grand Cherokee, commander, wrangler, neon,
If the online interchange is worth anything


Sent from my iPhone using Tapatalk

 

[Green Mesa XJ]

fuse F13 in the PDC controls the Servo, they say to check that then go on to trouble shooting servo.

 

[CorneliusRox]

If that part number for the servo is correct I'd hit a junk yard or eBay, it the same for dozens of vehicles even our 06 commander.
Liberty, grand Cherokee, commander, wrangler, neon,
If the online interchange is worth anything

That's good to know! I assumed the 96 or 97 style would have been updated.

fuse F13 in the PDC controls the Servo, they say to check that then go on to trouble shooting servo.

I did check all the fuses (every single one) in the engine bay and on the board under the steering wheel and replaced any bad one's, but maybe I'll swap F13 anyways.

 

[CorneliusRox]

I disconnected the brake switch and then lost TC Lock-Up and brake lights, so that's not a great way to test it. I'm going to see if the switch off my 95 YJ is the same and see if that works.

I had time to read through the Service Manual section, so I'll have some things to test. It's unlikely I'll have time tonight though... Have to clean up around my place for guests coming this weekend.

 

[90xj06]

check for codes using the key. also check section 8h in the manual i sent you it has the continuity checks for the brake light switch and speed control switch.

 

[CorneliusRox]

check for codes using the key. also check section 8h in the manual i sent you it has the continuity checks for the brake light switch and speed control switch.

I did check the codes and all that's left is the AC circuit code.
I'll be getting back to checking wires this weekend!

 

[90xj06]

did you check vacuum on the servo? may have gotten bumped and cracked while it was being worked on.

 

[CorneliusRox]

did you check vacuum on the servo? may have gotten bumped and cracked while it was being worked on.

I pulled the vacuum line apart after turning off the jeep and I heard air enter, so I assumed that meant the system was creating and holding vacuum. I didn't but a vacuum hand pump, but I could if you think that's worth getting.

 

[CorneliusRox]

fuse F13 in the PDC controls the Servo, they say to check that then go on to trouble shooting servo.

Also, I looked and I don't think I ever have had a F13 fuse (20A). Should I toss one in there for the Hell of it?