Electrical problem

[Cshenker1121]

I have a LS3 with a GM performance ecm and harness.

This things been driven quite a bit and was turbocharged but we recently took all of the turbo stuff off, and when I was hooking the battery back up (red top optima) getting ready to pull it out of the shop, I hooked up the cables backwards and it threw sparks,I quickly disconnected them and I put them back in the right place and it started up.

This new problem I’m about to explain didn’t happen until I got it back from a shop. When I turn the key and hold it, the starter cranks then acts like it loses power, then cranks again and starts right up. Any suggestions on where to start looking?

[Hotwire]

I would say to check the connections at the starter and make sure you have good ground straps going from the engine to the frame / battery. Might have lost some return path when you removed the turbo setup and it was forgotten?

[Cshenker1121]

I would say to check the connections at the starter and make sure you have good ground straps going from the engine to the frame / battery. Might have lost some return path when you removed the turbo setup and it was forgotten?

Last night I checked the starter connections and they seemed fine. Nothing was loose. As for the turbo stuff when I pulled all of the stuff off I completely removed all of the wiring and I checked last night and nothing as left undone.

Is it possible I messed up the battery? Or the starter? Or could this be another problem (ECU etc)

I fully charged the battery and checked it again and it still did it. Thank you for the reply! Trying to fix this myself before I go drop more money!

[srode]

I would take the battery to a parts store and have them load test it after you have it fully charged. Fully charged you should be around 12.75 volts after you take it off a charger and let it sit for an hour or so.