Hoping to get some help !
Last week I changed my fuel pump In my 08 4.2 pickup .
Before I disassembled it I turned the key to see if I heard the pump go on .Well my gauges started to twitch weird and then lost power . Battery died I did make the mistake of hooking the leads up wrong first positive connected then neg. Got a nice spark duhhh . well since then I can't get the starter to engage . Brought a new battery and alternator needed them . But now when I turn the key the starter just knocks one time and a few clicks at the fuse box just like my old truck ddid when the fender mount solenoid would go bad . But now my truck has all these ****y relays . any help would be helpful could my fuel pump mould cause this ?? Thanks
Billbob 1

 

If you haven't yet, check all your fuses. Connecting the battery backwards can pop fuses.
Have the starter tested. You can do this at most auto parts stores now.

 

Thanks I did have the starter checked and I checked it my self everything seams to be working just weird sounds just lime my old truck when the solenoid went bad

 

I have the original starter on my truck and somehow the power wire nut came loose from the starter. Caused the same issue you are having but intermittley. Worth the double check.

 

Thanks for the in put but I have checked everything and now I'm wordering if I pug the starter in upside down I don't think it will go in but one way . but it sounds lime its hiting the fly wheel maybe ?

 

Lol...cant stand this...

 

Well not that funny as I know now it only goes in one way . started testing all my grounds and found the braided ground going from my fire wall to some were behind the engine will assume its going to the block and it was only reading 3volts on my meter cleaned he one end and now getting 12 .75