'92 F150, 5.0, 5spd manual. Here's a new one on me. I turned on my A/C yesterday and came to a stop sign and my engine cut off. It started right back up, then cut off again. I started turning off loads, mainly the A/C, and it ran fine. Today it was doing it again so I started some experiments with different load pulls, headlights, radio, etc. and it only does it when I turn on the A/C. I'm assuming that the compressor is going bad and putting an extra strain on the engine, but why would it idle down and cut off?

 

it may not even have anything to do with the compressor. it could be a failing fuel pump or iac or a dirty throttle body. but when you have the ac on it puts more load on the engine and it just dies. has it idled weird lately?

 

its not throwing any engine codes? You might try taking the belt off and spinning the a/c pulley and seeing if there is any tension or grinding that you can hear?

 

Check for KOEO codes, but turn on the A/C first, and leave the switch on throughout the test, and see if you get any codes.

 

I've also noticed now that when I turn on the fan switch, even for the heat, my battery guage drops and then when I turn it off, it goes back to normal. I'll check everything else you suggested this morning. Thanks. -Al

 

You ever think about just getting a bicycle? lol.

 

Yeah, if I didn't love this body style so much, I would've given up on it by now. I had a '99 F150 and a 2001 F150 supercab and I sold them both and bought this '92 but I had no idea what I was going to run into. I'll eventually get it right if it kills me.

 

Have you prepared a Will yet? lol.

 

Have you had your alternator tested? Advance auto will do that for you for no charge. It might be worth a try. Also double check your battery terminals for tightness and be sure they are clean.

 

Thanks guys. I checked everything ya'll suggested and it all checks out okay. I pulled the plugs again today to switch back to Motocraft (was using Bosch) and 7 of my plugs had white tips, which I'm sure is from when my truck was a rolling volcano and had a faulty EGR sensor causing it to run lean, but one plug was not white tipped at all. In fact it looked like it did when it came out of the box. So, I'm hoping it's an injector. It's not the wires, but tomorrow I'm going to get a set of Motocraft 9mm just to be damn sure. I checked all of my pulleys and all spin freely except the power steering pump. It doesn't spin easily at all, but I'm not sure that it's supposed to. I'm going to search some posts and try to figure it out. This one's got me beat. -Al