I have a 2002 Xtreme. I have been searching blazerforum.com franticly and my problem seems to be a common one. Loss of voltage while driving and mild starting problems. I believe it might be the belt tensioner. when the engine is running should it be moving left and right about .25-.50 of an inch? I have a new alternator, battery, pos and negative cables. thanks

 

The tensioner will bounce around a little bit yes , but if its bouncing around alot then the belt may be stretched and needs to be replaced,, I did mine and put a V-groove gator belt on and havent had any probs yet..

 

If you give it a little bit of throttle does the tensioner still bounce or does it stay in place. Mine bounces a little at idle only if you give it the least bit of throttle it will stay steady.

 

a good way to check is to do this. Open up the hood with the car running, observe the belt at idle. Then by the intake pull on the throttle cable connector/linkage. hold it to about 2000RPM. Observe the belt. Does it look to be bouncing around? your starting/loss of voltage can be from a loose belt, it can also be because your battery is not up to shape because it is being drained from not properly charging. What is the Voltage at while driving?

 

check for movement back and forth, cheap fix for peace of mind imo, 1 bolt.