Hi Everyone!

I'm new to the forum but hope to become more involved with this awesome community!

I had an interesting experience this morning while on my way to work. About 5 minutes into my drive, I went to turn on the heat (it was about 20F outside) and quickly moved the slider all the way from the left (off) to the right (defroster). For some reason, my car just turned off. It didn't seem to sputter or do anything else abnormal; it just turned off. I managed to turn onto a side street, put it in park, moved the slider back to off, and it started without any issue. I slowly moved the slider to heat and it didn't give me any problem.

Does anyone have any idea what this could be? I planned to check the battery after work.

Thanks!

 

Maybe a coincidence? If you can't repeat it maybe you just have a failing CPS.

 

my first thought was also a failing CPS (crankshaft position sensor). Search forum for that and it will give you a good idea of what you are up against.

 

https://www.cherokeeforum.com/f2/96-...n-warm-246772/

https://www.cherokeeforum.com/f2/199...s-once-252539/

https://www.cherokeeforum.com/f2/96-...n-dies-254636/

 

Yeah, I'm voting for coincidence. OR, a really massive vacuum leak? Mebbe?

 

I had that happening to me as well.. turns out that my blower motor was so bad. that when I tried to run it.. It was drawing way too much power through the wires.... I went through three burned out ignition sets before it finally dawned on me to find the SOURCE of the problem and stop fixing the symptoms. once i replaced the motor and the relay.. no more burning out ignition switches.. no more xj suddenly going dead on me while driving at 70 mph on the freeway.

Not saying that this is YOUR problem.. but its what was causing my xj to shut down.

 

This is likely what is happening to him as well. The only mode in the 96 where the blower is off is when the mode is all the way to the left "OFF" position. My guess is that as soon as he moved the mode to the right, the blower motor started drawing and probably shorting at the ignition switch connector. This can knock out the "run" circuit that the ASD relay and computer need to keep the vehicle running. If that circuit is disrupted, ignition will immediately cease.

His first order of business is to pull the steering column shroud and inspect the ignition switch connector and the wires coming out of it for scorch marks, melted wires, and any holes (even pin sized ones) in the wire insulation.

 

one of my '96 used to lose all electrical power for a split second, never did get around to fixing it before someone ran into it

The '96 pulls all electrical power thru the Ignition switch..if just one thing in the chain of electrics to your Fan goes high resistance, good chance your ignition wiring will fry

as detailed afaic, 4 x relays inside to keep 4 speeds, feed power thru firewall from battery

 

1996 Sport, 4.0, mine did this over a period of about 3-4 months and then one day it would not start again. I'd be driving along and then it would shudder (ignition suddenly off and just as suddenly back on) as if it backfired, but no sound. This same event occurred several times. It was like a bucking motion because with a sudden decrease in engine speed and then a sudden return of spark the drive train would take a shock. Then, one day it just stopped running. I put the transmission in neutral and cranked the engine while moving and it started back up. It continued with this behavior until one day it would not start again and died altogether. The problem was the CPS. It took me awhile to fathom what the problem could be until I remembered a similar event happened with an acquaintance's car some years before and it was caused by a bad CPS.