fan belt question

[dave`12]

My engine comes from who knows what original vehicle. I've added aftermarket a/c and p/s. Because of this, when I bought fan belts, I had to measure rather give application. The only belts at the place I got them that were my length were notched, so I got them. 2 of the belts ride high, but I decided to try it out.

So, this morning, I go out to tinker and find that the alt belt has flipped around, with the notches facing away from the pulley! It was 2/3 on the pulley, which was still tight. One or 2 revs and it would have abandoned ship for sure. The engine had been ran for about an hour.

I have pictures of the engine after setting it up, and I know for sure that I put it on correctly. At first I thought someone was messing with me, but all my neighbors are cool, and being that I've been working on this project for a year now under a car port and have never had an issue, well I just don't think someone took tools, loosed it up, flipped it around, and put it back together.


So I need some opinions. Anyone ever hear about this happening? Some pics are below,
1st the alt pulley.
2nd the p/s pulley
3rd the crank, showing how they ride. The well seated belt is the a/c.

I'm guessing I should replace the alt belt, how about the p/s?