Vindicator9000

This is on a 94 Sport 4.0L.

In the time that I'd had it, it had seemed to charge a bit weakly (significantly below 14). It also had a bearing squeak that I suspected was coming from the alternator. So, I snagged a cheap junkyard alternator last week and threw it in to see if that helped. Now, it runs flawlessly with the AC off, and the charge gauge hovers just below 14. Does good with lights and hvac fan on. No more bearing squeak.

However, it now has a bad belt squealing/low charge problem with the air conditioning on. With the AC on, the belt starts squealing bad, and the charge dips quite a bit, and bounces a bit between 9 and 14, but closer to 9 most of the time. It doesn't get to the red, but it's too close for comfort. Runs great with AC off though.

As far as I can tell, I have the belt tension set correctly. The belt is straight around all of the pulleys and routed correctly. I have no idea what could be causing it to squeal so bad, but I'm thinking that has something to do with it not charging.

So, what could be causing this? Tension too tight? Tension too loose? Bad junkyard alternator? Bad belt? I'm having a heck of a time setting the tension correctly... the power steering pump doesn't want to move one way or the other, but the nut is set exactly where it was before I swapped the alternator, so I think it should be the same.

Ideas?

goneboating06

i was having similar issues with my cherokee, so i replaced and tightened the belt and it solved the problem. A good way to check the belt is when the engine is running with the A/C on, pour some water on the belt... if the squeal stops, its a bad belt... if it doesn't change anything then its not tight enough. Well, at least thats what a good mechanic friend told me. Hope it helps.

Vindicator9000

Thanks, that's kind of what I was thinking, but I always like to reality check here first.

Just picked up a new Gates belt for it, going on this weekend.