Faulty alternator or charge relay?

[michaelmotes]

geeves wrote:is yours a petrol model? whioch engine? They have a different settup
Yes, the petrol model. 3.2L V6 engine

[geeves]

bad alternator
either brushes or diode pack

[michaelmotes]

Thanks for the replies.

When I tightened up the fan/alternator belt, the problem revealed itself. Maybe the pulley was loose or slipped enough to loosen the belt, and then when I tightened the belt, the pulley just gave out.

I replaced the pulley bracket, and everything seems ok.



I just bought this Trooper with 180k miles, so I'm probably going to have to turn a wrench or two every now and then.

[geeves]

thats a different view of an engine. The other belts dont look to good either.
3.2 v6 in 87 trooper? the 3.2 isuzu engine was released in 92 The chevy engine was 3.1 and was used in some USA Troopers. What are the first 6 characters of the chassi number from the firewall plate (UBSxxx) and does it have any of these option codes? LL2, LW3,RJQ,RLJ,RLU,or RLV ?

[michaelmotes]

geeves wrote:thats a different view of an engine. The other belts dont look to good either.
3.2 v6 in 87 trooper? the 3.2 isuzu engine was released in 92 The chevy engine was 3.1 and was used in some USA Troopers. What are the first 6 characters of the chassi number from the firewall plate (UBSxxx) and does it have any of these option codes? LL2, LW3,RJQ,RLJ,RLU,or RLV ?
It is a 1997 Trooper. The AC belt is a little beat up but still working. It seems like the last owner or mechanic who installed the ac cut off a rib or two.

[michaelmotes]

So I had the same voltage problem on the way in to work today. After about 30 minutes of driving, the volts dropped from 14 to just below 12. Then the battery, brake, and trac lights came on. They would go off when the engine was above 2k rpms, but the volts stayed below 12.

So the pulley failure might not have been the cause of the initial electrical problem. The alternator is only 1 year old, but it could be bad.

Any other ideas, suggests, or comments would be much appreciated.

[proc09]

This exact thing happened to me a little while ago & it turned out to be that the altenator was fried. The copper wire that is coiled around the outside of the motor & the motor where all burned to a crisp. All the inside of the alternator was black, like it had been on fire. So I replaced the altenator & all is perfect now. I also upgraded to an 80amp alternator instead of going for the standard 50amp alternator. Now I can run my spotties, head lights & stereo all at the same time with no problems. The alternator that fried was the original alternator so to get 20 years out of it I think is pretty good. Although, my MU only has 162,000k's on it so it hasn't had alot of use. It still has the original air con gas in it & it is still cold, I don't use the air con though.

[michaelmotes]

Thanks.

[michaelmotes]

I had two shops do diagnostic tests. One said everything was fine and that maybe a bad ground was causing the lights to come on. But he had no idea why they went off when the RPMs went up. Also when the truck was running, the volts measured by their computer never went above 13 (i remember seeing 12.25). The other also initially said that everything was fine. However, then the manager came over and said that the volts should be between 13 &14, and they were again down in the 12s. So he said that the alternator needed to be replaced.

I just replaced the alternator. Parts stores only sold refurbished ones, so that's what I had to go with. I drove it around the block a time or two, and the dash warning lights never came on. However, the meter in the cab is still showing 12.

[michaelmotes]

We will see what happens with it today.