Fuel pump with LS engine

[SkidmoreGarage]

What do you mean by "arc-ed the battery"? If it just sparked when getting connected, I'd be surprised it fried an ECM (assuming a good wiring harness). If it was hooked up backwards... Or if the header install crushed some wires that shorted out... Then it would make more sense. Without knowing your exact wiring, have you confirmed that you are getting the constant power as well as the signal to the relay? If the relay appears to be getting a signal and it's a known good unit, try applying 12v directly to the relay power feed and see if it passes through to the pump with key on.

If you don't have a cheap multi-meter, I'd recommend picking one up. Checking for continuity would help you a lot.

[Ramiro0727]

Originally Posted by SkidmoreGarage

What do you mean by "arc-ed the battery"? If it just sparked when getting connected, I'd be surprised it fried an ECM (assuming a good wiring harness). If it was hooked up backwards... Or if the header install crushed some wires that shorted out... Then it would make more sense. Without knowing your exact wiring, have you confirmed that you are getting the constant power as well as the signal to the relay? If the relay appears to be getting a signal and it's a known good unit, try applying 12v directly to the relay power feed and see if it passes through to the pump with key on.

If you don't have a cheap multi-meter, I'd recommend picking one up. Checking for continuity would help you a lot.

SkidmoreGarage he was tightening up the negative battery cable using a ratchet. the ratchet hit the positive post and it arc-ed. we are using a american autowire power plus 20 wiring.

[SkidmoreGarage]

Understood, it's definitely possible to damage a lot of things with a current spike (especially in the ECM), but I'd be surprised if that is the case with the key off and arcing directly to the terminals. The electrons will take the path of least resistance, which is through the wrench. I'd also make sure your battery isn't dead by trying another battery.

I would look for melted or loose wires around where the work was done, it's possible a wire was pinched or a ground was left off.

It looks like there is a wire in your harness that is labeled fuel pump. I'd make sure this is getting 12V at the fuse panel and the relay. If that checks out, test to see if the relay is switching. Then manually switch the relay with a jumper and see if the pump runs. This will eliminate pump wiring.

[Ramiro0727]

We did what everyone recommended. We finally got the the fuel pump to power up. Turned out to be a bad ground from his engine to the frame. Thanks again for everyone who responded to my post.

Ramiro