Electrical issue

[UltimateG]

I've been having an electrical issue lately. I'm not experienced in this stuff, and hoping Y'all can tell me where to start looking:


This has occurred three times in the last few months. It happens at completely random times while driving. The electricity died in part of the jeep. It cut off for about ten seconds, then came right back on again like nothing happened.



The power went out to:

• Radio & instrument panel lights [Fuse 2]
• Heater fan [Fuse 5]
• Turn signals (but not hazard lights) [Fuse 8]

All other systems continued to run properly; the ignition, headlights, etc, were unaffected. I could not see the voltmeter during this occurrence, but the rest of the time it has been reading normally, around 12 - 14 volts.


This is the first time this Jeep has ever had any type of electrical problem. I don't know what brought on this issue, and I have been unable to repeat it on command.



I have replaced all the fuses under the dash. I'm hoping that helps, only time will tell. I did replace the alternator about six months ago, as the old one had developed squeaky bearings.



Has anyone else experienced a similar issue?

 

[jeep ride]

What year model jeep is you working on ?

 

[UltimateG]

Whoops.


1994 XJ Sport, 4.0, AW4.
100% stock.

 

[cruiser54]

It's likely the big brown wire at the ignition switch is melted and/or the switch is failing intermittently.

 

[UltimateG]

Nice, thank you.


Would that explain the power going out to only some systems in the car, while the engine kept running nicely?

 

[XJI6191]

Yes, because all those functions are "key on" & that's their supply wire.

 

[UltimateG]

Yes, because all those functions are "key on" & that's their supply wire.

Thank you.

 

[UltimateG]

I haven't gotten around to fixing the above problem yet, and now another issue has popped up. I'm curious if anyone can tell me if these two issues are related....

All of a sudden, the key won't turn in the ignition.
The ignition parts have felt a bit loose for some time now, but the other day, it got stuck completely.
A few times previously, it wouldn't turn at first when I put in the key, but after a bit of wiggling things around it freed up. Now, it is jammed completely. I can't tell where the obstruction is, but it feels like it's somewhere in the linkages in the steering column or ignition cylinder.

Is this a familiar problem? Is it related to that failing ignition switch? and how would I diagnose exactly where the problem lies?

Thanks!

 

[RCP Phx]

Could be the ignition switch or the cylinder lock itself!

 

[Unclewolverine]

I've had the back break off the tumbler twice.

 

[Saudade]

I haven't gotten around to fixing the above problem yet, and now another issue has popped up. I'm curious if anyone can tell me if these two issues are related....

All of a sudden, the key won't turn in the ignition.
The ignition parts have felt a bit loose for some time now, but the other day, it got stuck completely.
A few times previously, it wouldn't turn at first when I put in the key, but after a bit of wiggling things around it freed up. Now, it is jammed completely. I can't tell where the obstruction is, but it feels like it's somewhere in the linkages in the steering column or ignition cylinder.

Is this a familiar problem? Is it related to that failing ignition switch? and how would I diagnose exactly where the problem lies?

Thanks!

My guess is most likely.

The lock cylinder moves a rack inside the column. The rack moves a rod attached to the ignition switch at the bottom of the column. The ignition switch slides to connect/disconnect the various circuits for Acc, Off, Run, Start. When the Brown wire overheats, it melts the plastic connector, scorches the wire, and makes it lose contact. Melt enough and it can interfere with the switch sliding. It's possible that if the switch is jammed, and you try to force it, you may break something inside the column. (Let's hope not).

So does the key have any rotational movement? If so, you'll need to stick you head under the dash and observe the switch. Try turning the key and see/feel if there's any movement/flexing of the rod. If so, then the switch is likely jammed. If there's no movement, then it's possible the issue is higher up the column. You may also need to repair the connector anyway due to the original issue.

 

[RCP Phx]

When the Brown wire overheats, it melts the plastic connector, scorches the wire, and makes it lose contact. Melt enough and it can interfere with the switch sliding. It's possible that if the switch is jammed, and you try to force it, you may break something inside the column.

Since nothing was done about this last year, this is very likely !!!

 

[UltimateG]

Since nothing was done about this last year, this is very likely !!!

Damn. It appears that I have uncovered yet another Jeep issue that cannot be remedied by simply turning the radio up louder.

 

[UltimateG]

Solved.

Saudade was spot on. I replaced the ignition switch, and the key turns again. The switch had jammed.

I can't say if that other problem (intermittent power loss) is also cured. Time will tell, but I will assume that the expiring ignition switch was also the cause of the power issues. I noticed that the plug that attaches to the ignition switch was a little toasted. I'm guessing the 30 year old witch had overheated from a worn connection, eventually falling apart and jamming completely.

 

[Saudade]

Well Cruiser54 (RIP) and RCP Phx said it first. Glad you got it.

Nice work all!!