Fass dps 02 after market pump. I have 12v at the pump when I bump the key for 15-20 seconds. Then voltage spikes to 40v and over 3 seconds tapers to 0v.

I figured it had to be the pump since there was 12v. Brand new pump , nothing.

When problem first started my truck started and died in 5 seconds. Pump then stopped running. The fuse was blown on the after market harness. I changed the fuse , nothing and did not blow the fuse again. I tapped on the relay a bunch , truck started and I drove it 20 miles home. Once shutdown I tried to restart , nothing. Replaced relay , nothing.

What's odd is I'm getting voltage as I should with the relay pulled...

I'm lost

 

Codes?

Check ECM....

 

I'm an idiot theRe was no voltage spike.

Anyway no codes. Returning new pump. I hard wired it to a toggle and fuse and nothing.

 

Problem solved.heat shrink connection must have coroded to the point where I read the proper voltage , but wasn't getting the amps it needed.

 

Sweet. I have noticed the new de icer they use out here is pretty hard on non protected metal...

Maybe a problem where you live too.