Hey Folks.. I am new to the forum.. Long time lurker finally decided to join up..


I have a question for the experts. I have researched and no luck..


1999 XJ Part time light stays on all the time. 231 transfer case. Replaced 4x4 sending unit on the TC and the light does not go off. The jeep goes in 2WD and 4X4 fine. I can am sure the jeep in going in and out of 4x4. I did notice today that after taking the jeep out of 4H or 4L and going in reverse fast the light will go off, but as soon as I slow down in reverse it comes right back on...


I am now bound and determined that I am going to figure this out.. If anyone has any ideas on how to proceed from here I would appreciated it!


Thanks,


Dr. Jeep

 

Disconnect the 4WD switch at the harness. It may be inside the TC, and not the switch itself.

 

Thanks AJ... When unplugged at the harness the "part time" lights stays on..

 

It would be my guess that there is a short to ground that loosens enough when rearward momentum builds up, and re-grounds when at rest or with forward momentum. I don't have a FSM with a wiring schematic for your year.

 

No real help here with your light. Driving in part time on pavement might cause severe wear, with front and rear locked and likely binding. Being bound like that is why sometimes you back up a 4 WD, to free the tension so it can disengage. Just a note of caution there! On my 231 in my 90 I can tell by the feel turning tight, weather or not it's in 4 WD. In 2 WD, if you jack up one front you should be able to turn it. If you can't, you might toast something driving on asphalt! (thinking of the freeway makes me cringe)

In a pinch the front driveline can be removed.

 

DFlintstone,


I am 100% sure the jeep is not in 4x4 even though the light is staying on..

 

See if anything in the harness is chewed up or otherwise damaged. It travels along the transmission and jumps up to the main harness atop the firewall near the dipsticks

 

In theory, if you're driving straight on flat ground, there should be no binding, right? It's only when the road turns that you'd have issues, no?

 

In theory yes, but only in theory. If there is a slight difference in tire pressure from the front to the back that could cause a binding issue. The tires would be spinning a different rate even if it is only a few percent. In the long run it would ruin the transfer case. You would probably hear the case wining even driving straight.

 

Just out of curiosity.. When I bought the jeep the previous owner had just installed a 3" lift. If the linkage to the TC was not adjusted could that be a possible cause?


Thanks

 

Nope. The light is switched by the arm inside the transfer case, not the shift lever.

And adjustment certainly doesn't effect what happens when you unplug the wire.

 

Ok thanks.. Just a thought..

 

i would remove the bulb.

 

That isn't your issue.

But, if the previous owner installed a lift kit AND lowered the transfer case cross member (this is done to reduce the increased angles at the TC output shaft and drive shaft- remember, the output shaft should be parallel with the axle pinion shaft if there are only 2 universal joints and no double-cardan joint ), then the linkage should have been re-adjusted. The distance between the lever on the TC and where the linkage connects to the underside of the select handle would change slightly.

 

I have the same issue with my 1989. Can't find the 2 wire switch discussed above, on my truck, but I did find a broken vacuum hose that is one of 5 (?) hoses that comes off the drivers side rear of t/case. Repaired and light still on. Is my vintage different than the 99 discussed above?.....tried to find more info here but no luck yet (rookie here)