043500QC

Thats how I wired my dads Walbro setup. I used a 12v/40amp relay and used the stock wiring as a tigger for the relay. That sound right ?

Mopar1973man

There is another setup that is using a oil pressure switch and relay.

Basically the oil pressure switch keeps the pump from running till there is some oil pressure (Engine running) then starts the LP pump.

HiJenks

[QUOTE=Geico266]The FASS comes with a 12 volt relay wiring harness. The relay is activated by the stock LP signal, but delivers a 12.5v supply to the pump direct from the battery. Maybe a relay setup would help the Walbro.

I tapped the "hot wire" to the LP for the trigger to a relay.
The new lift pump works on the same cycle as original, on when ignition is switched on then goes off while cranking and back on. I grounded the relay and pump to frame so I only had the trigger wire and #10 power lead to run.

Mr. Wise

Been reading this thread and there seems to be some questions as to what kind of pressure the LP is suppose to be put out on the 2nd Gen trucks, so I'll give you what I have read in the Chilton's Manual. According to that, when the ignition is initiated the LP is suppose to put out between 5-7 PSI. After that regardless of position of the throttle it's suppose to be 10 psi.
I'm in the middle of installing an ISSPRO mech Fuel press gauge on my truck with an isolator so I can watch this at all times from inside the cab. I'll let you know if I see different.