'95 YJ alternator(?)problem

OK, so I'm driving to work. Cruising along, not a care in the world at about 60mph. All of a sudden the Check Engine light comes on. Upon looking at the gauges, I discover that the dash lights are dim and the volt gauge shows that the alternator is not charging. Just from habit, I push in the clutch and rev the engine. The volt gauge goes back to 14.5v and the dash lights get bright again. Of course the CE light stays on. Continued on towards home and this repeats itself a couple of times and then, the last 30 miles were trouble free. Got home and checked the codes. The only one I got that was new was a

41(or maybe 42, I've slept since last night). "alt field open or shorted" Now, I heard a nasty rumour that DC put the voltage reg in the 'puter on these Jeeps and not in the alt., although my book(a Chilton's)says different. Am I looking at a wiring problem or possible failure of the alternator or ECM? I know it would be a lot easier to diagnose if it'd quit altogether, but I'd rather not have to go through the "dead on the side of the road" stage, as the weather around here is supposed to turn nasty and I've still got the 135 mile round trip to work to do every day until Friday. Oh, and what's with the damned thing throwing an a/c clutch relay code, when it doesn't and never did have a/c?

-- Old Crow '82 Shovelhead FLTC 92" 'Pearl' '95 Jeep Wrangler YJ TOMKAT, BS#133, SENS, MAMBM, DOF#51, SPONGER#2

Reply to
Old Crow
Loading thread data ...

Old Crow did pass the time by typing:

Loose/dirty connection probably

On the ZJs at least it's part of the ECU. But with what your describing I'd check for loose connections first. Last time I had that problem I gave the battery cable a tug and it popped out.

The A/C fault code on a non A/C equipped vehicle is normal. It's always there, just won't turn the CE light on.

Reply to
DougW

Well, due to our snowstorm, I had time over the holidays to look at the damned thing. Took the connections at the alt loose, sanded them and re-installed the alt, also set the belt a bit tighter than it had been. Took the battery loose(actually the first step

Reply to
Old Crow

ok, i just had this problem in my 93 yj. last monday night was barely over 0 degrees. the next morning, still only 2 degrees. i noticed i was getting no charging at all. about 10 minutes after starting, then my charge came back. it hasn't happened since (temps were over 25 all week). tonight is going to be around 0 again, i will see what happens.

Reply to
MudPuppy76

MudPuppy76 did pass the time by typing:

Odds are the same thing. A low or no charge. Check your battery fluid, sounds like your battery is freezing up or a cell is going dry.

Could also be your battery is old. Cold kills weak batteries.

Gets too cold you migh have to do what my dad did up in montanna. Take the battery inside over night. They make thermal blankets for batteries, and heaters.

Reply to
DougW

i'll check tomorrow when i get to the shop. pull out that battery acid tester (gathering dust)

Reply to
MudPuppy76

Well, I did my 133 mile commute yesterday with no porblem...I'm saying it's fixed...for now. I suppose if I convert this thing to a 'real' GM one wire alternator, I'll have to pull the bulb out of the check enging light or get used to looking at it :-)

-- Old Crow '82 Shovelhead FLTC 92" 'Pearl' '95 Jeep Wrangler YJ TOMKAT, BS#133, SENS, MAMBM, DOF#51, SPONGER#2

Reply to
Old Crow

I see that lots because I off road. The mud or liquid sandpaper polishes up my belts and they don't grab well when cold.

I test it with a cold off engine and see if I can hand slip the alternator pulley. If I can hand slip it, it is dead or loose. The alternator takes several HP to spin up under load and for sure if it hand slips it won't charge fully if at all.

Mike

86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00 88 Cherokee 235 BFG AT's
Reply to
Mike Romain

MotorsForum website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.