well .. he found a short, but because I'd been driving it, the computer got damaged and we need a new one. Does this sound right? The Alt gauge goes way up when we rev it. This is damaging something else. (sorry I didn't really understand all the explanation)

problem is, I won't get it for who knows how long this time of year ..

Until then I need the truck! Can I just disconnect the alt from the system, so I don't damage anything more, and drive on the battery alone? Maybe two 20 mile round trips, not turning it off,

and charging the batt at night?

 

The bottom line sounds like the voltage regulator (VR) function within your PCM isn't working, hence the need to replace the PCM.

 

Some have mounted external regulator when the PCM has broken.

 

Yeah sorry but I don't understand electrical,

Can I just disconnect the alternator, so I don't damage anything more, and drive on the battery alone? Maybe two 20 mile round trips, not turning it off,

and charging the battery at night?

 

Get the # off your pcm (computer brain) on the fire wall on the passenger side. Look it up on ebay and you should be able to find a replacement.

 

My mechanic ordered it already but might take days, and I need wheels now. So how about my question abouty disconnecting the alternator?

 

It will run till the battery goes dead. So, the more electrical load you put on it, (headlights, heater, etc.) the faster it will drain. When voltage drops low enough, the truck will simply stop running. The battery by itself won't run the truck for long, so, no, that's not really a viable option.

 

Any idea how many miles will it run on battery alone?

 

Too many variables. Might go 10, might go 100....

 

How about a new, fully charged battery, with nothing else on.? I just need to make a 20 mile round trip tomorrow to pick up materials for my crew.