Decided to change the serpentine belt on my 1990 W250. The previous owner had one in the box of stuff that came with the truck. It is a Mopar Q4080817. I assumed that that was what the old one was. It was a real bitch to get on. I could just barely get it over the alternator pulley with much cursing and swearing. I replaced one on a Ford F250 in half the time. It looks like there are 3 different length belts for this truck on Ebay. The old belt was not hard to get off but because of the difficulty of putting the new one on I'm doubting that it's the right belt. I cut the old belt and laid it out on the floor. It measured 81 5/8". The Dayco belt, K5080820, according to their literature is 82.09", roughly 3/8 to 1/2" longer than the old belt and that's the one I ordered online. I can't see that that would change the circumference too much that the tensioner couldn't handle it and it would make it a little easier to install. Hope I'm right.
My rig has AC but I doubt that it works since I never use it. So is there any reason that I can't use the non AC belt and just bypass the compressor?
There was something mentioned about 'inter-cooler'? What's that and would I have one on my truck? What's it look like and where would it be located?

 

yes you can. if the old belt was fine and not chirping i would leave it. last time it took me and my buddy to put the belt back on his diesel. i think the trick is slipping it onto the water pump

 

When looking down at the tensioner pulley I could see many cracks in the belt ribs. When I took it off and inspected it I found some longitudinal cracks about 1" long. Since I've never changed it and I don't know when it was last replaced, it seemed like a good idea. I'm going to order the non-AC belt as a backup. I'd hate to have to change this in the rain. Talk about a bad day!