Atr Doublepump Wiring

[sparkwire]

I have a atr doublepump FP it has only one relay for the pumps, looks to me like both pumps run all the time, it has the hot lead from the alt.with 25amp fuse,to relay,single hot lead from relay to yellow connector on tank unit.2 small wires from bottom of relay short leads, there are 4 wires in the yellow connector blk grd blk wht tracer hot, purple sending unit, gray don't know. the purple and gry are in a double plug connector.
I ask because the F body double pump harness has 2 relays and separate hot line for each pump so both pumps don't run at the same time. second pump runs at higher boost. ANY IDEA?? THANKS

 

[WyoSyclone]

Re: Atr Doublepump Wiring

If pumps are running in parallel, then each could run with a separate relay and appropriate check valves. If pumps are running in series, which would be weird, they'd both have to operate all the time... do you know if they're set up with separate pick ups?

 

[sparkwire]

Re: Atr Doublepump Wiring

I believe the relay i have,sent with the pump is only for the second pump and the fp relay i have,in the truck now runs the first pump, the seller sent me a PM maybe he will explain. THANKS