Hey guys, so my truck has a vapor lock problem, and after not having any success resolving this issue by insulating the fuel lines (from the fuel pump to the carb) I decided to install an electric fuel pump with a fuel pump controller sold by LMC Truck, manufactured by Revolution Electronics, but I'm having some issues.

After installing both the electric fuel pump and the controller, I found that the controller is not powering up the pump.

Does anyone here have any experience with this fuel pump controller p/n 12003?

It has one black ground wire, that I connected to a well grounded screw in the sheet metal, a red wire that goes to a 12v switched power source, a green wire that goes to the tach wire on the ignition module, and two purple wires. One purple wire goes to the starter solenoid, the other to the electric fuel pump.

What I've found is that when the engine is running the purple wire that goes to the fuel pump does not have any current, it is supposed to be powering the fuel pump.

I've tested the controller following the instructions provided by it (see this). I do hear it clicking for 3 seconds when turning the ignition key to on, but it's not powering the fuel pump.

Has anyone here had this problem? I'm starting to think the controller is defective.

Any help is appreciated. Thanks.

 

which post on the solenoid did you connect to purple wire?
do you have 12v on the other purple wire for 3 seconds after the key is turned on?
I assume the fuel pump runs when directly connected to 12v (bypassing the controller)?

 

The purple wire connected to the starter solenoid is on the side that goes to the starter, not the side from the battery.
I don't get any current on the other purple wire that goes to the electric fuel pump when turning on the ignition switch. I do hear the controller clicking once and then again after 3 seconds.
I haven't tested the pump without the controller. I figured the problem is with the controller, since there is no power going through the purple wire connected to the pump.

 

I have one on my truck and the pump would only run for a couple seconds then shut off for a few seconds then back on. There was a little diode in the box that says to install across both terminals across the pump and it solved the problem. The orientation of the diode does matter.

 

The only time that post has voltage is when you are cranking the engine.