I have an 89 1 ton, and the water pump just let out a few drops from the weep hole, So i went off to Pep boys and bought a new
Bosch water pump #29408-1 $69.95 and a new
Dayco belt tensioner # 30529 $ 69.95 Thinking that it needed a replacement while i was there,,, Well the install went smooth as hot butter, Then i started up the old rig, And she fired right up, But there was a noise akin to a bottle rocket going off,,,MMMM Shut er down and found nothing, Restarted, and had a sound like a zip tie hitting the rad fan, shut it down again and looked and looked, found nothing, so i ran it with the noise,, Not it is daylight, I poked around for a while and found that the alternator fan was hitting the tensioner pully housing,
The alt is not stock, It was replaced before i bought the truck, I believe it was from NAPA, It is an Excel #7552,
One moment with a small file on the tensioner housing cured the issue,
Those of you that replace your tensioner pully assy, Spin that alt with downward force, and check the clearance before you are scratching your head for 1/2 hour wondering where that noise is coming from.
Happy day!!!

 

I told you that alternator looked funny.

Glad you got it up and running, Peter.

 

I guess that is is an oddball alternator, Goes with the oddball driver., excel is a brand from napa, And i as hoping that some folks here will file this info away in their heads.