Hey guys,

Last night, I was on the freeway going a steady 65 and my Tahoe felt like it went into REP mode, but no check engine light or anything, it just didn't really respond to throttle input. It felt like it was stumbling a bit, similar to when it runs out of gas (but had 3/4 of a tank). Then after 5-10 seconds right before it shut off, it displays "Battery Not Charging."

I put it in neutral, put my flashers on and coasted it down the exit ramp and pulled into a parking lot. I waited a few minutes, then tried to fire it up. It fired right up, ran for 30 seconds, then, without stumbling or anything, just turned off. I called a friend to come pick me up, but while I was waiting, I fired it up again and let it idle. After a few minutes, I thought, why not try to make it home on the surface roads so I can put it in the garage for the night. Made it the 3 miles home like nothing ever happened.

I am completely stumped. Bad alternator? What does the Battery Not Charging typically mean if the truck shuts off? Electrical problem? Fuel pump related (has a Walbro 450 with a Racetronix harness, but it hasn't missed a beat in the last 6 months since installed)?

Thanks for any guidance

 

I answered your PM, but I'll post here also for others to see.


I have seen trucks with similar symptoms in the past. It is usually a loose connection in the battery cables system. Often at the battery, or at the post on the starter. Sometimes the starter solenoid will be found cracked or partially melted, allowing the post to have intermittent contact. Corrosion on & in the cable ends is also a concern with your symptoms. Check every single cable connection point very closely, they need to be clean and tight. If all of that checks good, it could be worn out brushes in your alternator, or an internal plate loose in your battery. Either of those will give intermittent open circuits, and your described symptoms.

When the open circuit occurs, your PCM will freak out. It needs a rock solid consistent power source, and a rock solid ground in order to do its job properly. After all, it's a computer that uses voltage to do its job. Good luck on the repair, let me know what you find.

 

Thanks bud, I'll definitely check out all of those recommendations and report back, hopefully tomorrow if it warms up.

 

Checked the underhood connections. All snug, no broken wires, no fraying. Drove it a couple of times and no issues. Going to investigate further as it's clear I have a problem.

Sadly another problem has reared it's head, getting a whining from the rear end. Going to pull the cover and check the backlash and bolts because I don't know what else it would be.

 

Batterys are wierd these days,the way they can act when they fail,try another know good battery


couple of months ago I bought a 01 denali XL .AMCO told them it needed a tranny,bought it cheap.Shut off on me once.then batt dead,replaced battery ,truck became perfect.

 

I'll get the battery tested, but it should be good; it's a DieHard Gold that's only 6 months old.

 

Could very well be a loose plate in the battery. Problem is, it will probably test okay because loose plates only fail intermittently. Very hard to "catch it in the act".

 

Battery and alternator tested good. Alternator was measured at 140amps. Doesn't necessarily rule it out though, the guy said you'd have to catch it in the act if it is having problems.

 

I was cutting some ridiculous dough nuts one night and the truck would sputter and die when drifting to the right. I ended up pulling the small positive wire to the fuse box out of the stock battery crimped connection.

It was in the plastic housing just fine visually, but after pulling on all of the wires while it was running, the dinger came on and died just as you're describing.

 

a bad crankshaft sensor can cause this problem also