Fass Pump Dead

[garylmoore]

I parked the 2001 Dodge Ram while I was putting a catch can system on. It's sat for probably a month what you started up yesterday and I have no pressure from the Fass lift pump no noise.
Everything work fine when I parked it I there were no problems at all. Nothing I installed or touched came anywhere near the lift pump or its connections. I'm looking for where I should start.
The fuse is a double 10 amp accessory lead to #9 fuse on left side of dash. Both fuses in lead check fine. I'm going to see if I can get the connector apart at the Fass and check for power. Gary

 

[garylmoore]

I pulled the accessory connector and plugged it into the cigar fuse and the pump ran. Ends up the accessory connector lead comes out the right side and was hitting a rib in the fusebox. I bent that wire up and the pump worked again.
Sorry for posting the silly mistake.
Mods, pull this post if you like Gary

 

[Wiredawg]

Hey Gary, there's value in posting troubleshooting like this. That is the "True Value" of the TDR. Thanks, Ron

 

[petersonj]

If I am understanding correctly, your lift pump is wired directly to a switched ignition source. If this is true, I recommend to completely rewire the lift pump circuit. You could be putting yourself and others at risk should your truck be involved in an accident that could potentially cause a leak in the fuel supply line from the lift pump to the VP44 injection pump. The lift pump could continue to run without the engine running and ignition key left in the "on" position risking a fire at the scene.

In a stock lift pump operation, the ECM supplies voltage directly to the lift pump. If the above situation occurred, the ECM would disrupt power supply to the lift pump.

People have modified the lift pump power source to reduce the electrical load of the ECM by using a relay. In this case the ECM supplies voltage to operate the coil of the relay only. The internal relay switch handles a different source of power to supply voltage directly to the lift pump.

It would help if you can provide detailed information of exactly how your lift pump is wired.

- John

 

[garylmoore]

If I am understanding correctly, your lift pump is wired directly to a switched ignition source. If this is true, I recommend to completely rewire the lift pump circuit. You could be putting yourself and others at risk should your truck be involved in an accident that could potentially cause a leak in the fuel supply line from the lift pump to the VP44 injection pump. The lift pump could continue to run without the engine running and ignition key left in the "on" position risking a fire at the scene.

In a stock lift pump operation, the ECM supplies voltage directly to the lift pump. If the above situation occurred, the ECM would disrupt power supply to the lift pump.

People have modified the lift pump power source to reduce the electrical load of the ECM by using a relay. In this case the ECM supplies voltage to operate the coil of the relay only. The internal relay switch handles a different source of power to supply voltage directly to the lift pump.

It would help if you can provide detailed information of exactly how your lift pump is wired.

- John

You are right, it is wired to run anytime the ignition is on.
I go from the lift pump to a relay with three red
and a green wire.
This is plugged into slot #9 in the dash fusebox via a fused accessory wire.
Do you have a schematic of the proper wiring?

 

[Wiredawg]

If I am understanding correctly, your lift pump is wired directly to a switched ignition source. If this is true, I recommend to completely rewire the lift pump circuit. You could be putting yourself and others at risk should your truck be involved in an accident that could potentially cause a leak in the fuel supply line from the lift pump to the VP44 injection pump. The lift pump could continue to run without the engine running and ignition key left in the "on" position risking a fire at the scene.

In a stock lift pump operation, the ECM supplies voltage directly to the lift pump. If the above situation occurred, the ECM would disrupt power supply to the lift pump.

People have modified the lift pump power source to reduce the electrical load of the ECM by using a relay. In this case the ECM supplies voltage to operate the coil of the relay only. The internal relay switch handles a different source of power to supply voltage directly to the lift pump.

It would help if you can provide detailed information of exactly how your lift pump is wired.

- John

John, good to note proper connection of power to the FASS/lift pump. It's the details that make or break an upgrade.

Cheers, Ron

 

[Topzide]

@garylmoore, Sent you a PM

 

[petersonj]

@garylmoore , this is a diagram from Mopar1973Man site. You will have to find the yellow / white wire downstream of Splice 160 (OEM wiring diagram below) and utilize that wire to activate the coil of the relay. You should verify that you have power to that wire from the ECM by doing the ignition on test (about 1/4 seconds) and the bump start test (runs for 20 seconds). Hopefully, the ECM power source still works.

- John

 

[garylmoore]

I can do that. Thank you for your effort!
Gary

 

[garylmoore]

@garylmoore, Sent you a PM

I received the drawing. Thank you.