Battery drain on a 99 Tahoe

[djfive45]

Are you saying completely dead? You didn't say. The first place I always start is by unplugging the alternator and see if drain goes away. You can put a DVOM between the negative post on battery and the cable end and measure milli amps and post that result here. If alternator unplug does not take care of problem, then you start by unplugging fuses, while DVOM is attached, and see what circuit fuse stops the big milli amp draw. All this needs to be done with a completely charged battery. Make sure you don't have a hidden light on somewhere. Any work done before having this problem?

Before I put a new battery in it last year I dod notice a clicking noise in dash about the middle and the CD player was making a strange noise and had a hard time ejecting a CD. Some kinda relay maybe?

 

[OR VietVet]

Disconnect the power to that unit or pull a fuse/relay and see if that does it. But still check the alternator.

 

[djfive45]

There are diodes internally in the alternator. They are designed to allow current to flow one direction. If they fail and allow current flow two directions, that can cause a draw on the battery. If you unplug the alternator and that stops the draw, it means you take the radiator cap off and drive a new vehicle under it and install the radiator cap and you are good to go.

NOOOOOO....it means the alternator should be replaced.

Hahaha. Thanks for the info,I'm not all that familiar with electronics. Enjoy the humor

 

[djfive45]

Hahaha. Thanks for the info,I'm not all that familiar with electronics. Enjoy the humor

Unplug the positive cable and other wire from alternator correct?

 

[djfive45]

Thank you for the info

 

[Fless]

Not judging, but it seems like you might want a more knowledgeable person looking at it. There are standard methods and tools for diagnosing (parasitic) battery draw and until those are used, it's just a crap shoot to find what's causing it -- if there even is one.

Oodles of YouTube videos on diagnosing parasitic draw.

 

[Hoesgottaeat2]

Are you talking about the fuses under the hood? The cluster guy I talked to said to pull the cluster if it still has a drain he mentioned some fuse under the hood. Have to go back and read which ine he said.

Inside the driver's door below the A-pillar

 

[OR VietVet]

Unplug the positive cable and other wire from alternator correct?

Unplug it. You don't need to remove any nuts and unscrew a cable. Just unplug it.

 

[djfive45]

Not judging, but it seems like you might want a more knowledgeable person looking at it. There are standard methods and tools for diagnosing (parasitic) battery draw and until those are used, it's just a crap shoot to find what's causing it -- if there even is one.

Oodles of YouTube videos on diagnosing parasitic draw.

I agree .thank you for the help

 

[east302]

I'll take visor vanity mirrors as my first guess.

Don’t forget this one Djfive. If the plastic cover on the visor is broken, that little light will stay on.