How to wire up parallel fuel pump switch?

[Tinman]

I have the Glacier 392 pump and would like to put a switch in the cab to switch between the Walbro and stock pump. The Walbro starts to suck air at around a 1/4 tank while braking and it would be nice to be able to switch back to stock for those rare occasions where I let the needle get down that low. Plus I'd like to run the stock pump every now and again to make sure it works in case the Walbro every quits (unlikely) out in the boonies. I don't want to run the power wire in the cab and thru a switch. So how else can I do it? I'm sure someone makes a remote switch but I'm not familiar with such an item.

 

[rbattelle]

I'd suggest a double throw relay to shut off the Walbro pump and turn on the stock pump. You can put the switch for it wherever you want.

Ryan

 

[Tinman]

Thanks a bunch rbattelle. Using your advise, I did some research and brain storming and finally got this all worked out. Found a suitable relay at NAPA and hooked it up with the relay that came with the GDP system. Moved all the wiring from under the truck to under the hood. The Walbro is grounded to the frame and I tied into the stock pump wire behind the driver front wheel behind the fender. The hot wire to the Walbro is the only wire on the frame rail. I have a switch in the cab to activate the SPDT relay and it works like a charm. I can toggle between the Walbro and the stock pump and the motor doesn't miss a beat. Pressure gauge just changes pressure. The 2 micron filter certainly adds resistance to the stock pump. Lost 2 psi at idle and can easily pull it down to zero. But that's OK, it's a back up pump. I appreciate the help.