2005 Avalanch Parasitic battery drain
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2005 Avalanch Parasitic battery drain
2005 Avalanche 5.3 2wd. no aftermarket electronics at all.
A few months ago My battery would be dead flat only in the mornings about once a week. If I would jump start it, the alternator would be putting out 14 V and the truck would run fine with no issue for a few days at least. The problem slowly became more frequent until it finally started happening mid day. The truck is parked next to my bedroom window and has not had alarm or horn issues at all. I walk past it at least a couple of times a night and check for light or anything else that could be the cause but no lights, radio etc. Radio is not on.
I started doing what I could on a fixed income so all of the following efforts were done over the period of a month with the problem continuing to get worse.
The battery was less than a year old but I replaced it anyway,
I replaced the alternator having been told the internal voltage regulator was probably bad.
I then replaced the regulator and A/C blower motor as they had been sketchy for a while also.
I replaced the light control panel that has the dash light dimmer switch.
I disconnected the ground cable and put a meter inline to measure amperage of the drain. It only shows about a 4A drain and this is where my lack of electrical knowledge really shines. My battery will go from 12.8V to 6V in about 4 hours. Maybe I am over simplifying the math but it doesn't appear that 4A would drain a new fully charged battery to flat dead in less than 8 hours.
I bought a FLIR camera and identified several breakers that would heat up when the truck was in "sleep mode". Doors all closed, engine off with key away from vehicle for over 20 minutes. I would remove the suspect ( warm ) breakers individually and only 2 affected the drain at all but not totally.
When I would remove the "15A TBC 2B" breaker the drain would drop from 4.1A to 2.88A. This was repeatable over time. If I also removed the "10A RT TURN" the draw would further drop from 2.88A to 0.3A. This was only repeated a few times in a dozen tries over the next few days.
the "15A TBC 2C" breaker also heated up on the FLIR but there was no evident drop in draw when I would remove it.
I have removed ALL of the breakers under the hood and dash individually with no apparent change other than the 2 mentioned above.
While I am no automotive specialist at all somehow it seems that some of my results are contradictory so I have repeated most all of the previous efforts including replacing the in components that I bought cheap off Amazon with OEM components.
Really hoping here someone will make me feel silly for overlooking the obvious. I have been to a very highly respected local shop that only does automotive electrical systems and while they guaranteed they would find the exact issue, they wanted me to leave the truck for 3-4 weeks while waiting in line for service.
Thanks for any input. Phill
A few months ago My battery would be dead flat only in the mornings about once a week. If I would jump start it, the alternator would be putting out 14 V and the truck would run fine with no issue for a few days at least. The problem slowly became more frequent until it finally started happening mid day. The truck is parked next to my bedroom window and has not had alarm or horn issues at all. I walk past it at least a couple of times a night and check for light or anything else that could be the cause but no lights, radio etc. Radio is not on.
I started doing what I could on a fixed income so all of the following efforts were done over the period of a month with the problem continuing to get worse.
The battery was less than a year old but I replaced it anyway,
I replaced the alternator having been told the internal voltage regulator was probably bad.
I then replaced the regulator and A/C blower motor as they had been sketchy for a while also.
I replaced the light control panel that has the dash light dimmer switch.
I disconnected the ground cable and put a meter inline to measure amperage of the drain. It only shows about a 4A drain and this is where my lack of electrical knowledge really shines. My battery will go from 12.8V to 6V in about 4 hours. Maybe I am over simplifying the math but it doesn't appear that 4A would drain a new fully charged battery to flat dead in less than 8 hours.
I bought a FLIR camera and identified several breakers that would heat up when the truck was in "sleep mode". Doors all closed, engine off with key away from vehicle for over 20 minutes. I would remove the suspect ( warm ) breakers individually and only 2 affected the drain at all but not totally.
When I would remove the "15A TBC 2B" breaker the drain would drop from 4.1A to 2.88A. This was repeatable over time. If I also removed the "10A RT TURN" the draw would further drop from 2.88A to 0.3A. This was only repeated a few times in a dozen tries over the next few days.
the "15A TBC 2C" breaker also heated up on the FLIR but there was no evident drop in draw when I would remove it.
I have removed ALL of the breakers under the hood and dash individually with no apparent change other than the 2 mentioned above.
While I am no automotive specialist at all somehow it seems that some of my results are contradictory so I have repeated most all of the previous efforts including replacing the in components that I bought cheap off Amazon with OEM components.
Really hoping here someone will make me feel silly for overlooking the obvious. I have been to a very highly respected local shop that only does automotive electrical systems and while they guaranteed they would find the exact issue, they wanted me to leave the truck for 3-4 weeks while waiting in line for service.
Thanks for any input. Phill