Dear Friends,

Having driven our "new" GMC very little since it came home (about 2 months ago), I felt it was time to take it on a short trip preparatory to taking it any distance. During the last few weekly start ups, I noticed an increasing "belt" sound. Today, I set aside some time to go down and tighten what I assumed was the alternator belt - as putting a load on the alternator seemed to exacerbate the noise. Sure enough, the belt was somewhat loose - perhaps deflecting 2 inches.

I figured out how to undo the alternator and with my son pulling on a large lever, we tightened the alternator so it deflects about 1/2 inch, perhaps a hair more.

Start up and VERY loud noise. Shut things down quickly. The Alternator belt is warm, the AC belt is HOT. Dash heater/AC controls were set to "defrost" then
"off."

Took out the magic elf box (smart phone) and video recorded another start up. (Happy how it starts right up) Would you experienced souls take a look and listen? I don't think its the alternator belt as the sound seems to be coming from the passenger side. My son went outside of the coach and confirmed that from the outside front it sounded like the passenger side.

The dash AC does hot work (coach has 3 roof top units) and the air intake under the "hood" is blocked off to stop drafts I suppose.

Video here

Thank you very much for your time and consideration,

John

John,

Remove the air cleaner and get a BRIGHT light and hold it above the front of the engine so we can see what the fan is doing. It
sounds like the fan is scraping on something.

Regards,
Rob M.