2000 Tahoe LS 4x4 trouble starting (and staying running)

[jjc6df]

I just purchased a 2000 Tahoe LS 4x4. It has 118000 miles on it.
I noticed after I purchased it, it was slow to start. I replaced the battery (which was only 630 CA) with a battery that had sufficient cranking amps and have had no trouble until today.

This morning when I was driving to work, I noticed my dash lights and the display on my radio were dimming as I was driving. Sometimes they were bright, other times they were dim, but did not notice anything else out of the ordinary.

When I left for lunch, the Tahoe turned over and started, but immediately shutoff. This happened several more times while attempting to get it to stay running. Eventually, it stayed running, but the voltmeter would fluctuate, especially when I would slow down. When I would come to a complete stop the engine would shutoff, then fire right back up. However, after drving for 5 minutes or so, it seemed all was well again with the voltmeter planted at 14 or 15 volts and no issues.

Has anybody else experienced this?
Any ideas what the issue could be?
Any recommendations to resolve this problem?

It seems like a possible ignition system problem.
Perhaps the distributor or alternator or starter?

The whole Tahoe experience is new from me -- I come from a long line of import sedans with FWD and manual transmissions. I'm slowly adjusting to the new ride. So, any help/guidance/assistance is greatly appreciated.

Thanks in advance.

 

[bunkleman21]

When the lights dim like that I automatically assume alternator. Sounds like it is not charging the battery, what is throwing me off is the voltmeter going back to 14-15. Usually when the alt goes the volts go down and stay down. If you need to jump start it and it slowly quits when the cables are taken off I would say the alt is your problem.

 

[JKmotorsports]

Yea, check the alternator. If it isn't working and the battery is low, the ignition system isn't getting the power it needs to run the coilpacks and spark the plugs.

 

[jjc6df]

Thanks for the guidance.

I had the alternator tested t the local AutoZone, and it passed (twice) with flying colors. I reinstalled the alternator and have not had any more issues until tonite.

I just drove about twenty miles and upon returning home parked the Tahoe in my driveway. I turned it off and took the keys out of the ignition and the doors did not unlock as they usually do. I put the key back in the ignition and turned forward to accessory and nothing happened -- dead battery.

I am now of the belief that there is a bad connection between my battery and alternator, and therefore my battery is not charging as it should be. Hence the trouble starting and (now) having a dead battery.

Does that sound like a possible cause of my problems?

Thanks again...

 

[jjc6df]

Some more information of relevance:

Sometimes the Tahoe starts no problem, while other times it cranks and cranks and cranks and won't start. When I give it another try, it starts up instantly.

Perhaps the wire from the ignition to the alternator is faulty?

 

[lskipper]

just my 2 cents, might go back and check the battery again. Just because it is new, doesn't mean it is OK, it might have a bad cell.

 

[shadow]

Sounds like you might have a faulty battery cable, or bad corrosion on one or both cables.

Good idea to check them (and clean them good) periodically.

Similar thing happened to me on another car, and it was a bad cable, that would work OK for a bit, then be "dead" for a while, then be OK again. Drove me nuts.

 

[jjc6df]

Thanks to all for the advice.

I seem to have missed the extreme corrosion on the positive battery cable when I was installing the new battery. I'm surprised any contact was made at all (between the battery and the cable) -- it was that bad.

I cleaned the corrosion from the cable.
The tahoe now runs like a bear through the woods.
Problem solved.

Thanks...

 

[shadow]

Crazy how some of the "simpler" things are the root cause of some of these electrical problems.

My Tahoe '00 5.3L had a defective battery (original AC Delco) where the postive post developed a leak, and bled acid to the contact.

2 replacements later, and it really had put a lot of acid corrosion on the terminal end.

Keep an eye on those cable connections, at least once a year.