Chevrolet Repair: drive belt routing, double pulley, chevrolet blazer

Question
1980 Chevrolet Blazer 4x4 with aftermarket A/C, 350 motor, 4 speed manual transmission: Slung all belts off.  I need a routing diagram to put on new belts.  There is not one under the hood. Any help/advice is appreciated.

Answer
Hello Tanya,
That's gonna be a toughy.
It should be the same as most any 1980 pickup. I would assume that even the aftermarket a/c used a stock compressor mount.
A salvage yard would be a good place to see an older model like that.
A trip to the public library, refference section, would let you look at manuals that age.
Motors, and Chilton manuals usually have a section with vacuum hose diagrams, but the manuals I looked through here just don't have a belt diagram. Probably due to the vast array of different engines, and different possibilities of belt driven accessories.
At the library, you should be able to find a shop service manual for that exact truck, and it would probably have the different arrangements for that year.

Another way is to take something straight, like a yardstick, and lign up pulleys. Only pulleys directly in line with each other can be driven by the same belt.
Then buy the belts at a good parts store, by application, and do some experimenting till you get it right. They might even have an exploded view on their computer monitor, and let you look at it.

If I am not mistaken, the power steering belt goes on first. From there I would just have to look.
I have a neighbor across the street who owns a 79 pickup, but he is working right now. Later, when he gets home, I can look at his, and give a more detailed answer if you still need it.
It will help to know if your alternator has a double pulley, or a single.

If you try to match them yourself, look in all the belt grooves. Some may not be used, and you can see that by the wear, or lack of wear in the pulley grooves.

While checking that, rotate all the pulleys, and see if you can find why it slung them off in the first place....locked up compressor, bad idler pulley, or a pulley out of line, unless you know that something got into them and caused it.

Good luck,
Van