FASS Power Supply on 04.5-05 TST

[Stab]

TST and FASS instructions are vague on the power supply for the FASS 150 with TST installed. I DO NOT have a fuel pump relay. Where should I hook the positive side of the FASS MAIN power supply? I know I need to take the fuel pump off the back of the fuel filter housing and use the supplied manifold fitting included with the kit. And hook the wiring harness into the pump circuit at that point, but where does the positive line go that is supposed to go to the positive side of the battery, but that TST recommends hooking to the relay that I do not have??



THANKS!

 

[Yo Hoot]

I think they are talking about the stock relay in the fuse box



On a ‘03 and early ‘04 Dodge:
DO NOT CONNECT A PUSHER PUMP POWER WIRE TO EITHER FUSE 36 OR 50 or to the “spare” fuse or relay.
Doing so will destroy the circuit board in the POWERMAXCR™ timing harness when the truck is running
during Cool Down. If your pump has been moved to the tank, follow the instructions below for a ‘04 1/2 to
‘05 Dodge. Otherwise, make sure your pump kit has a relay to power the pump.


On a ‘04-1/2 and ‘05 Dodge:
DO NOT CONNECT A PUSHER PUMP POWER WIRE TO EITHER FUSE 36 OR 50 or to the “spare” fuse or relay.
Doing so will destroy the circuit board in the POWERMAXCR™ timing harness when the truck is running
during Cool Down. Remove the Fuel Pump Relay. There should be 5 pins. Not all relays are labeled on the
bottom, so use the drawing on the side of the relay to identify the pins. Pin 87 puts power to the transfer
pump. Bend pin 87 out to the side so you can connect a mini female spade terminal and connect it to the
pusher pump power wire. Connect the pusher pump ground to the battery ground.

 

[Stab]

I DO NOT have the stock fuel pump relay in the fuse box. The fuel is controled by the ECM.

 

[Yo Hoot]

I have a TST installed a long time ago... . back in 2004. I just installed a FASS system a couple of months ago. Using the FASS instructions I tapped right off the positive battery terminal.


Looking at the FASS instructions it seems they don't have a special 2004. 5 listing. BUT both the 2004 and the 2005-up call for connecting directly to the battery terminal.

Now... . if you do that and the pump runs without key on than you are correct, you need more instructions. Otherwise there must be feed from the harness at the old lift pump that will control it.

I am almost positive your FASS gets it's signal from the harness and gets it's power from the battery terminal.

 

[Stab]

That all makes sense. I'm just concerned about the circuits on the TST. Trying to get a hold of TST!

 

[AllianceDiesel]

Luke you home yet? Ok here is the deal on the newer trucks they don't use a fuel pump relay the ground is controlled through the ecm. What we thought about doing, is splicing into the power wire that runs into the stock pump on the back of the filter housing. But I don't know why they want it to be tapped into a relay.



Is this like a double redundant system so that if one relay sticks on then the other one will kick off when the cool down timer shuts off. Or, is this a way to protect the circuit board on the tst. The tst/fass instructions don't make any since for this truck.

 

[Stab]

Got a reply from TST and as long as the FASS system has a relay in the main power supply we can hook directly to the battery like the FASS instructions indicate. TST's concerns are; pulling power through their circuits to power the main FASS pump, which burns them up.

 

[AllianceDiesel]

so did you get it hooked up yet?