Lift Pump Electrical Circuit Issues
 

I just installed a rebuilt VP and AirDog 100 over the weekend. I'm having problems keeping power to my LP. Can I just wire this thing direct with a switch or tie into a circuit that's keyed on? I also bought an Actron CP9180 Scanner. The only code I get is "Crankshaft position sensor". Could this be effecting my fuel pump circuitry? That wouldn't make any sense, but a lot of the circuits on these trucks are screwy! I'm picking up and replacing the Crank PS today. Did the Cam PS while I had the VP off.

This is directly from a Dodge Tech Manual. I can only assume that if the ECM thinks the engine is not running due to a faulty Crank sensor it will cut power to the LP. Does your tach act funny?

It hasn't worked in a while. Ocassionally it will for a few seconds. I'm replacing the Crank PS today. I'll post if it fixes the problem.

Are you still using the stock LP trigger wire for the new pump. If not you should be, and run a relay switch from the battery to the pump for power.