Odd issue. I was in the middle of replacing my alternator. I wasn't paying attention and I did not hook up the wires from the alt to the batt. Now my racetronix fp is getting power from the alternator directly through their harness. However, before realizing my error, I started the car and it ran just fine except for low volts...obviously since the alternator was not charging the system. I don't understand how I could get fuel pressure and the car running fine with "no power" to the pump?

Also, I was hoping the alternator would fix a couple small electrical issues with my lights. When I hit the brakes, the lights would sometimes dim on my head unit. The issue is still not resolved.

Any ideas on this stuff?

-Brian

 

If the motor is turning over, the alternator is sending a charge out the back, hence powering your fuel pump. It just isn't recharging your battery.

You could have a short with your brake lights and headlights so that when the brake lights come on they're grounding the circuit or something. Try looking at the wiring diagrams to see what's on that circuit.

 

well to make it clear, nothing was attached electrically to the back of the alternator so it was not getting power from that. However, I asked my installer and he told me the pump still gets power from the stock harness but is aided by the upgrade harness which gets power off the alternator.

I cleaned all my grounds and check it over and it all looks ok so I'm kind of stumped. Wish someone with good electrical experience was around my area.

-brian

 

Well, if you still had it plugged into the stock harness, then that makes sense.

 

yea...I felt like an idiot after he told me but in my defense I never saw the instructions and figured that the racetronix harness was the only thing powering the pump.

 

Thats a cool feature rather than just crapping out completely.