I have a 1993 W350 w/auto. My alt., a/c, and overdrive, all stopped working at the same time. Also my "wait to start" light comes on after I start the engine, and stays on. I was told it could be my crank speed sensor. I put a new one on, but it didn't fix it. Now I'm being told it is probably my PCM. What do you all think? I dodn't want to by one, if that's not the problem. But if I do need one, where is the best place to get one.

 

I got it fixed. Thanks anyway.

 

What was the fix? 60amp fuse maybe.

 

It was the "auto shutdown relay". It's on the drivers fender. The one towards the front of the truck.