The 4WD light on my 1999 XJ's dash isn't working and the weather hasn't been conducive to crawling underneath to check the transfer case switch and wiring. Is that light supposed to turn on with the ignition as a test like the other warning lights? (It doesn't.)

 

I don't think so, but that's more of a guess than an answer. The light on my '01 wasn't part of the system check (or was burnt out).

 

I think you're right. I'm pretty sure that light is not triggered by the computer, it's just a simple circuit operated directly by the transfer case switch completing a ground. I'll have to check the switch and the bulb the old-fashioned way.

 

That is correct. Just a basic circuit.

 

Won't start again. Crank position was changed, Throttle position was changed, coil was changed, has spark and fuel.
Started it this morning it idled high and the check engine came on. Idle went back to normal. I shut it off to check the code and it won't start back up. Code was 55 so that's no good. I'm out of ideas

 

Define "won't start"

 

Cranks for days just won't fire. My guess is a sensor is preventing spark or the ECU isn't making the injectors spray

 

Well yank that **** apart and figure out which it is, then. lol

Checked fuses?

 

Fuses are good. I pull/replace them every day to stop the parasitic drain.

 

He does that so he can start his Jeep again when it's time to leave. Battery drains very rapidly and won't crank after a short time

 

That's hilarious.

 

It's the weirdest thing. Drain is on the ECU circuit and the internal fuse panel circuit. Got it down to 3 seconds in and out.
For even better comedic value, I leave the hood popped when it sits and sometimes I'll come back to the jeep and people close it for me. Lol

 

Hi there,
I have a few questions.

1) Will a failed CPS cause the vehicle to stop running (while it's on) or just not turn back on (after it's turned off)?

2) Can I use a CPS from a 4.0 on my 2.5?

3) Can I use a Distributor pick up coil (HO style) from a 4.0 on a 2.5? (I'm finding ones for the 4.0 are much cheaper than for the 2.5, just wondering if they are engine specific or not as they look identical)

I have a 94 Cherokee 2.5 with no spark. I also have a 91 Cherokee 4.0 that recently had the same problem (turned out to be Dist. pick up), but I had replaced ignition coil & CPS before discovering the real culprit. I still have the original CPS from the 4.0 that I replaced that I'm assuming is still good.

Thanks.

 

1 yes
2 no
3 no

 

99 xj 4.0: would a loose serpentine belt make it hard to start?