Hello, I am new here. I have a 93 E150 with the 4.9 engine. My alternator went out. I was going to replace it myself. But I couldn't figure out how to get alternator out. So I took it to a mechanic, and he put it on for me (I provided him with the alternator). As the subject line states, now there is a squeaking sound. I want to sell the van, but I can't sell it with it squeaking like this. I took it back to the mechanic and he sprayed a bunch of brake clean on the belt, but it still squeaks. I think it is up to me to fix the issue since the mechanic did the job I asked of him: install the alternator. He charged me $250, which is reasonable. He said he had to pull the radiator because the fan clutch wouldn't come off. Do you have any ideas about what might be causing the squeaking? The mechanic said it could be the old belt was accustomed to the old alternator, and maybe there are slight differences in size between old and new. So the first thing I will do is put on a new belt. The mechanic also said it could be the tensioner. I don't know anything about tensioners. I will Google it. Maybe he screwed something up when he failed to get the fail clutch off? Or maybe the alternator is bad? It is a rebuilt alternator that I bought at Autozone. I am really stressed out about this. I didn't have the $250 to spare in the first place. Now I have a new problem, and I don't have a lot of time or inclination to do repairs.(I live in an apartment complex without a garage). The mechanic explained to me what I needed to do to replace the alternator if I wanted to take my new alternator back. It will require removing the radiator, but at least all the bolts are freshly turned. Thanks for your advice or insights.