Hello, Just got done installing a new High Output DC Power 185A alternator. I had a heck of a time getting the belt back on. But, when I got it back on, the belt was rubbing on the belt tensioner. I know its not supposed to do that. So, I got my hand down onto the tensioner and budged it slightly to the left. Now, I have about 1/8 inch clearance between the belt and belt tensioner. It was rubbing on the belt tensioner's pivot point, not the pulley part. Now, I have clearance. Just wanted to make sure that 1/8 inch is okay?? It is not rubbing anymore. Any ideas what the clearance should be?? After clearance, the blazer started right up. Oh yeah, Its a 2000 chevy blazer 4dr 4x4 4.3L V6. My volts are reading in excess of 14.4V on my gauge as well as on my head unit. Hope you guys can help me out. Thanks.

 

The belt tensioner is what you use to release tension on the belt with a 3/8" drive ratchet. It should be pretty easy to remove & adjust the line of a belt. Getting it around & in the grooves on the other pullies is crutial. If one is over a groove it could set the rest off.
That being said...
Are you sure the new alternator is lined up properly? It may need a 1/8" washer as a spacer behind it where it mounts to the bracket/block to align the grooves to the other pullies.

Could you get some pics of it missaligned & realigned?
It sounds like something else may have come loose or, as I said the alternator isn't set up the same as the stock one. IE: it's a little thinner, lobes where the bolts go through are thinner etc.

 

I got all the belt grooves in the right places and the belt lines up perfect. Just wanted to know why the belt comes so close to the tensioner when the belt is in place?? Might I need a bigger belt? I will try to get some pics in.

 

I had to buy and install a bigger belt. One inch bigger. Works great now!