wannabeturbo

I wanting to run dual relays for my fuel pump for redundancy. I want to wire one relay to be triggered by the pcm and the other to be triggered by the key. My question is if I run dual relays with a 10g wire and 10g output off each relay meeting at the pump so I'll have two 10g power wires running to the pump and have the relay from the key witched to power and the r delay from the pcm switched to groud and both relays grounded at the same point will the one that comes on with the key back feed the relay off the pcm or will it be fine?

AgFormula02

iTrader: (13)

what are you trying to accomplish with this redundancy? Just trying to understand the logic as to what benefit you would gain from this.

wannabeturbo

Trying to build redundancy into the fuel pump wiring in care a wire gets pinch or something so the fuel pump would still run. And I'm having a iusse getting enough prime time on the ecu to get the car to build pressure and fire the 1st try so I thought running one off the key would help that and one off the pcm so it would trigger the 2nd relay

stevieturbo

Dumb.


You do realise that when you key on, the PCM primes the pump anyway ? And as soon as the key is turned to start the engine, and the crank is rotating the pump will be running too ?

Wiring a second relay in on key only is dumb, and foregoes the OEM safety feature that prevents the pump running with the engine stopped, ie in event of a crash etc.