I put a new belt on my MAH5500BWW and the new belt slips off after one or two turns. Ideas

fan belts squeak for several reasons 1 incorrect belt for pulley.2 belt running on the botton of the pulley and worn pulleys. To check measure across the top part of the pulley and the widest part (back) of the belt should be the same if not marginally bigger. V belts work best at t5he top of the pulley.If you can see that the pulley is polished at the bottom the belt is slipping and not driving Check if the pulley sides where the belt runs is not stepped from wear. Recheck the tension as new belts stretch slightly. If you have a multi groove pulley check the tension setting. As a last resort CRC make a product that is used to stop belt but it is best to fix the real fault first

The power steering pump pulley must be flushed with the power steering pump shaft,Or else you will have noise or slips right off.

try cleaning the cogs that the belt runs around some times the belt puts a layer of rubber on them when the belt slips which makes the new belt slip if not could be a bearing in the pullys the belt runs around

hi Paul.
see if this link helps to find out why.
1998 ford escort zx2 serpentine belt keeps slipping off Google Search

Small hands are handy for this job. Be glad you drive a 325 and not a 330.
First take note of the routing of the belt. On this car, it is physically possible to put it on wrong and spin the alternator backward.
You then pop off the plastic caps from the tensioner pulleys, and use an allen wrench to turn the center bolt to rotate the tensioner against its spring to release tension on the belt, and slip off the belt. Careful not to pinch your fingers when slipping the belt back on.
Some tensioners have a hole where you can stick a pin, such as a big nail, through to hold the tensioner back while you slip on the new belt. Those make it easier to put the new belt on. I have not found those on the e46, but I have not taken the time to look for them.
While the belt is off, spin the pulley(s). If they chatter, replace them. The top two pulleys usually need replacing about every 75k to 100k miles. How long the bottom pulley lasts seems highly variable from car to car for some reason.

One of the pulleys or idlers is bad now that you have a new belt. Take off belt and check them .

It's not the tensioner pulley. It's the tensioner itself. The spring on the inside has become weak allowing the belt tension to move it just off of "square" to the engine do it's acting like a cone. Smaller on one end than the other. The belt wants to drift towards the smaller end and comes off. Think of it as your arm with a glass of water in your hand extended out in front of you. At first you can hold the glass of water just fine...but after awhile your arm gets tired of holding it there. What happens?

see if that vehicle came without A/C. If so ck for the belt availability and see if it can be put od bypassing the compressor. At the least, disconnect the compressor clutch wirin g so the A/C will not function at all. until you can manage a the cost of a pump. Good luck, Ned

All u need to do is put a wrench on the tention pully and turn it clockwise... this will relive the tention take off the old belt ....put on new one. repeat relive pressure again ...slip it on pully... and relese tention..... done! :)

I need the firing order for a 98 ford escort