thesixs

OK this is seriously weird. Hubby takes '94 rodeo hunting when he comes back, battery is dead (no deer are though some irony here), gets a jump and tells me to buy him new alt. He charged up the battery and it started this morning with out changing alt. He decided to replace terminals and clean up the corrosion on battery. Ran to local store to pick up new terminal ends and when he got there, the truck wouldn't shut off. He took the key in with him and the truck was still running!! When he got home he noticed that the rear defog light was on even though the button was in the out/off position. He was more than a little annoyed and pushed the switch to turn it off. The truck shut off!! The light on the switch stayed lit even though the truck was no longer running. With the switch pushed in/on there is no instrument panel function. Also if you remove switch or fuse no instrument panel function. He even tried unplugging it in the rear window and that made no difference whatsoever.

He has now torn the dash panel apart and has had the switch out. Now the car will turn off with the switch in the on or off position, but if it is in the off position, no instruments. If you turn it on, you have instruments, but when you shut the truck off the anti lock brake light and the rear defog light remain on. You can remedy this by pushing defog button again, but then you'll have no instruments when you start up.

Can anyone help?? PLEASE!!

trooperbc

i can only tell you that a defective or intermittent defective alternator will cause all sorts of devilish behavior with the dash lights and even the automatic transmission. however, your saga is wonderfully new -- to us used the same old stuff, i know not to you.

anyway, before spending forever trying to figure this one out using the electrical schematic, i would get that alternator tested at the local parts store, or a shop that can do installed. you will want to make sure it gets tested 'under load', for the test to be meaningful.

if you do need to get a new alternator, don't go for the cheapy bigboxparts store'sunlimitedlifetimewarranty one.
instead consider the more expensive alternatives that will really be worth the extra dollars
*dealer new if available. very big $$$$$
**dealer rebuilt. very good. also not cheap
***rebuilt by bosch. less expensive, but not cheap, and my choice from experience.

btw, the fact it started up with a charged battery but no alternator change would be normal. if the battery then discharges during use before you can get the charging system tested, you can pretty much bet on the alternator being the problem. (although it could still be a defective battery).

what does the dash volt meter show. while not conclusive, lower volts there would be another indicator of a problem. (the volts could read within spec, even though you do have a charging problem, since you are not also reading amps.


hth


//bc

__________________
1992 trooper 3.2L v6 sohc automatic...as is

i love a good intermittent electrical challenge. . .especially when it's someone else's.

thesixs

Ok so before reading all the posts on which alt to buy or not we had already purchased said alt at (cringe) autozone. Anywho hubby installed and it didn't make a darn bit of difference . Now when the the truck is turned off the dash lights stay on unless you push the button on the rear defog switch. As for what the gauges indicate, they say the charging system is working fine and dandy. We will keep in mind the alternator advice. I am thinking about getting a new switch for the rear defog.

Hubby would like to know if there are any other grounds besides the one from battery to frame and frame to engine? We have a Chilton's off the rack manual and the wiring schematic is less than helpful.

Thanks for the help appreciate any further advice.

thesixs

Husband wanted me to add that the switch for the rear defogger has 5 wires. Only the brown and yellow have power to them. The yellow has power when the switch is on, the brown has power all the time. None of the others have power any time.