Ok, here goes...the car won't start quit a bit, when I shake the negative battery terminal hard it seems to help the car start. Once it starts it runs fine until it gets hot in the engine bay, then things go nuts, every two minutes or so while driving all dash lights flicker for a millisecond and the car stutters hard also for a millisecond. Other times when the engine bay gets quite hot it will go haywire with the dash lights going nuts and the car sputters to a stall. I'm forced induction with an Odyssey slim battery and many many many other performance mods, so any info anyone needs to help please please ask...p.s....I've done a quick look over bay wiring and nothing seems glaringly wrong.

 

Ok, here goes...the car won't start quit a bit, when I shake the negative battery terminal hard it seems to help the car start. Once it starts it runs fine until it gets hot in the engine bay, then things go nuts, every two minutes or so while driving all dash lights flicker for a millisecond and the car stutters hard also for a millisecond. Other times when the engine bay gets quite hot it will go haywire with the dash lights going nuts and the car sputters to a stall. I'm forced induction with an Odyssey slim battery and many many many other performance mods, so any info anyone needs to help please please ask...p.s....I've done a quick look over bay wiring and nothing seems glaringly wrong.

 

Are your battery terminals showing any sign of corrosion? May want to try replacing the negative battery cable or see of a buddy has one you can swap.

That's what I would check first at least of you haven't already.

 

Terminals not corroded at all, and that negative likely runs all the way back to the ecu....correct?...or does it just run to numerous grounding spots.

 

way to post this in 3 areas lol. maybe some wire is shorted or grounding out somewhere. if your harness is still stock see if you can trade for a quick second with someone in your area so see if it still work. that way you will know if it is your harnes

 

numerous grounds, and the issue seems more alternator oriented

 

Would the alternator cause electrical ground issues, and dash.lights to flicker only when, and it is only when engine temps rise and I get into boost.

 

Lol, I've been on this forum for a long ___ time, there was a reason for the three posts first off bra...and not it is not stock, I'm running boost with a boomslang aem fic controller....its a shielded harness so the main wire harness is still running stock location.

 

The negative is just going to run from the battery to a grounding point on the car. Check your grounds and like mentioned (now that I think about it) the alternator can be a culprit too.

 

Also I can't explain how the alternator could only cause issues when the car is warm. But if you have a bad/loose ground, it could be that when you are driving, you hit a bump or turn or w/e, causing a ground to love around, which can affect electrical systems.

 

Fixed, please close. Fix was: the shop I had swap my clutch out, I'm guessing, raised the bell housing back up after clutch install...mounted bell housing and didn't realize the forgot to connect the negative battery ground on the housing...and there is no way to get to it without removing the starter and in my case, intake pipe and blow off valve. With that said I think they got lazy and hand tightened it cause it was loose, so I removed the before mentioned parts, tightened the ground down and all good as it stands now, consistent starts, no dash flicker and good boost when the engine is running hot.

 

Fixed, please close. Fix was: the shop I had swap my clutch out, I'm guessing, raised the bell housing back up after clutch install...mounted bell housing and didn't realize the forgot to connect the negative battery ground on the housing...and there is no way to get to it without removing the starter and in my case, intake pipe and blow off valve. With that said I think they got lazy and hand tightened it cause it was loose, so I removed the before mentioned parts, tightened the ground down and all good as it stands now, consistent starts, no dash flicker and good boost when the engine is running hot.