Got a 87 4runner for 650 dollars so yea it has more than rust issues but it runs good and all except when I turn on the AC no prob with heater just ac. It basically kills the motor when you push the buttton in. I dont know where to even begin to look but the po pos thought he was an electrical engineer and speaker wire could run lights and every thing else. anyhow any direction in what to look for would be great otherwise I'll just keep driving without ac not that I'll use it much anyways just wondering what could cause this. Plus it was 650 dollars for a running working 4x4 toyota so I cant expect it to be perfect. Here's some pics.

 

Check the clutch on the a/c compressor or the compressor it self. Sometimes the clutch or the compressor can lock up and when you turn on the a/c that can cause the engine to stall. Unplug the power wire that goes to the a/c compressor and then push the a/c button and see what happens, if it stays running then you have found the problem, if it doesn`t, then it might be an electrical problem.

 

The other thing you can do is reach down and turn the compressor by hand. Common sense dictates to do this while the motor is OFF. If the compressor is not locked up, you will be able to turn the inner pulley freely by hand, and the outer will stay stationary.

 

Wow guys thanks for the quick replies. I'll try this and post results thanks.