Thread: Fuel pump primes with headlights...

So, if I turn on my headlights the fuel pump will prime. WTF could cause this? I am no eletrical guru so I could use some guidance. I'd appreciate any ideas/help. TIA!

You should state that you're running an AEM. Your wiring for the pump may be fed from an incorrect 12v source.

you running a aem series 1 unit? I had this problem its ground related. The aem is ultra sensitive to grounds. I ended up isolating all my grounds for the electronics I had added to the car. The aem will also do weird stuff when the battery voltage is low. You could also move the fuel pump to another definable output.

Is this with the key off?

I can also confirm this is a aem series 1 issue. when I was trouble shooting I took the aem out and put the stock ecu in and the problem stopped.

Have the outputs been changed around ?

This is clearly an output setting in the AEM EMS or a wiring mistake under the dash. What you need to do is select an output, then run a fresh wire off that ECU Pin to a relay that will trigger the pump to see if that solves the issue. This bypasses the stock nissan fuel pump wiring.

Sorry guys just got out of work. I am running the AEM series 2 ems.

We planned on running a direct 12V via relay. I just wanted to figure out this issue before anything. I will have to look into and see as I haven't changed anything. Wired in the map sensor and thats about it. I don't remember the car doing this with the calum ecu. I'll see if it does it while the key is in the off position or not in the ignition at all.

Bes just move the fuel pump to another out put. I was going to do this myself but after I went through my wiring for my gauges and other electronics the problem went away. I know that mine was ground related. Not that I had bad ground points but I had too many things grounded together which is usually not a problem. I figured out that my prosport gauges were causing the pump to prime when the head light switch was turned on and off. I unplugged the gauges and it stopped.

Wow thats some ish! Call me a moron but what exactly do you mean by output? Pardon my moronicness