Is there a way to check the PCM to see if it is bad or over charging or under charging without taking it to the dealer? Will the codes on the odometer tell me??

 

What do you mean by over charging or under charging. What does the truck do or not do?

 

Well my Air dog has gone from 15psi to 25psi with a high pitch whine, when I go to drive it the pressure falls off and so does my voltage gauge in my truck. When I turn the truck off it will start back up but the head lights and interior lights are all sort of dim. Also with the main battery disconnected the dome light is still on and the truck acts like it will start if I try it, whats up with that?

I spoke with pure flow and they are sending me a new pump because the G rotor is bad but they don't see how that would effect my voltage?

 

Start the truck and check alternator output voltage. Put a volt meter on dc to the battery posts. You want like 13-14 aprox. If not you might have a bad alternator. Also I would load test the two batteries and clean the terminals.

 

Thanks the alternator checks out and the Batteries are brand new. I believe the problem is coming from the load that the bad pump is putting on everything, as soon as I accelerate and the pump starts to push fuel it blows a fuse.

 

Well put the pump on and keep us posted. I really dont think you have a PCM problem doesnt sound like the syptoms of a bad computer. If a vehicle with a bad computer comes in my shop 9 out of 10 times they have a ton of codes and most run poorly or dont run at all. Im not saying thats not your problem but chances are its ok if no other syptoms exist.

 

Thanks CTD01 I will let you all know tomorrow after I put the new pump in.