I was driving my 1990 Comanche yesterday, and there was a squealing sound under the hood and my battery light came on. Also, my power steering went out briefly. This seems like a problem with the belt, as it provides power to both the alternator and the power steering, but I am no expert. I need to wait until it stops raining, or the sun comes up at least, to open her up and check the belt, but does it sound like I'm on the right track?

 

It can be that or one of your pulleys is starting to drag. You should remove the belt and make sure that all your pulleys spin freely and that there isn't any side to side in the pulleys.

 

X2 ^^. Also, before you remove it, I would make sure that the belt itself has enough tension. They are made of rubber, and can stretch over time. But definitely remove it and check all your pulleys.

 

Well, I believe the problem has identified itself. I went to warm her up, and within a minute the belt just broke. So I guess that must have been the issue. Just five minutes ago. Installing the new belt this weekend will give me a good chance to check the pulleys, but that belt was just plain tired looking.

How much of a pain is it to install a new belt on one of these older trucks?

 

$10 says the belt isn't the problem. Since it's gone aways spin all the pulleys by hand to see which one is locked up.

 

Totally agree. When my S10 belt broke, it was the alternator locked up, that resulted in the battery being drained.

Expensive repair, New belt, new alternator, new battery.

 

I will double down and say its not the belt... Pulley or idler... The new belt will break or burn up just the same...

 

I've had my suspicions about my alternator. I hope that's not the issue but if so, it would be nice to have a new one. My truck has a myriad of electrical "quirks" which I thought might be rooted in the alternator. I will make sure to test all of the pulleys by hand before doing anything else. You're saying that if the alternator pulley is locked, that means I need to replace the alternator?

 

It's the alternator.

 

OK, new questions:

Replacing the alternator seems like a straightforward job, how long should it take? Any specialty tools I will need? Or will my regular set do the job?

Thank you all for your help, forgive my general ignorance of car repair. I'm new at this, and all of your expertise is really helpful.

 

There is a recent alternator thread, search. Apparently best to drop it down and also loosen the bracket bolts. Never done one on a 4.0L. Should be just metric sockets.

 

No metric sockets iirc, but its plain simple. The alt is in the passenger side lower motor, its 2 bolts and about 5 minutes of work

 

It's a jeep so it's definitely metric sockets. 2 or 3 bolts (ivr done a couple since one so I can't remember for sure) hold it on place and two itty bitty ones hold the electrical connections on the back side. The hardest part of the job is getting the alternator in and out of position.

 

Well, hey, that's not too bad. New belt and alternator shouldn't be more than $130-$150, and at least I don't have to take the belt off! So far, if this works, I've still put less than $1000 into Rusty. All the other pulleys are in surprisingly good condition, considering everything on, in, or around this truck is rusted through. I'll order the parts and get to work. I doubt the NAPA in Juneau, Alaska has a spare alternator laying around.

 

Why would a JEEP have metric bolts ???? I do not know about that one ... Last time I worked on my Jeep it was SAE.

thanks, Randy from Oceanside