2013 LC200 - HVAC turns on when car is off!!! (4 Viewers)

[eminaise]

Every other time I've had an issue with my 2013 LC, it's been a "me" problem (like the time I couldn't get the native GPS screen to go dark (i was lowering my headlights not dimming them!)). This time i think there may be something wrong. Our cruiser started having battery issues (i.e. car wont start after being parked for a couple days). replaced the battery with the Costco special in Sep 2024. less than a year later, it's happening again. We cruised the Natchez Trace Parkway (in a rental car) for spring break and back at SeaTac, the car wouldn't start. Our usual trusty charging brick couldn't do the trick and we had to call AAA. long story short, we got it started. Now a month later, we have a dead battery again. Thinking that it's a phantom drain on something, we bought a new $$ AGM battery thinking a larger/better battery will give us more time for the phantom to work and hopefully less "car won't start" moments. Also, I've got a funeral to go to this week and don't have time to dig into it myself until later this month.

Then walking by, I hear the HVAC fan has somehow activated when the car has been turned off. like the car has been turned off for 2 hours, the keys are nowhere near the car and you walk by and hear the fan. I think i found the phantom. Any suggestions? I started the car, then turned off again and the fan (not the motor fan, the interior HVAC fan) was still running.

Turned on again, turned HVAC system "OFF" while the car is running then turned off and it's no longer on. Clearly there is a short somewhere because it's never happened before.. anyone else experience anything like this? Recommendations?

 

[Sandroad]

Whenever there are posts about electrical gremlins, I think of corroded connectors from water in the wrong place. It's all too common to have corrosion in the electrical connectors in the door sills from leaks and/or clogged sunroof drains. Bad windshield install jobs and leaking cowls cause corrosion in connectors too. Pull up the door sills and check all the connectors. Details can be found in several other posts on electrical gremlins. If you find corrosion (likely), also find the water source after you clean things up.

 

[bloc]

Pull up the door sills and check all the connectors. Details can be found in several other posts on electrical gremlins. If you find corrosion (likely), also find the water source after you clean things up.

This.

 

[studawg]

Reminds me of when my fog lights were on in my 2013 with the vehicle and lights off after a heavy rain.

Found water/corrosion in the big connector in the driver side kick panel. Cleaned and dried it out and was fine.

 

[krice118]

My aunt had a similar issue. Turns out some rodents had chewed a ground wire

 

[gaijin]

Every other time I've had an issue with my 2013 LC, it's been a "me" problem (like the time I couldn't get the native GPS screen to go dark (i was lowering my headlights not dimming them!)). This time i think there may be something wrong. Our cruiser started having battery issues (i.e. car wont start after being parked for a couple days). replaced the battery with the Costco special in Sep 2024. less than a year later, it's happening again. We cruised the Natchez Trace Parkway (in a rental car) for spring break and back at SeaTac, the car wouldn't start. Our usual trusty charging brick couldn't do the trick and we had to call AAA. long story short, we got it started. Now a month later, we have a dead battery again. Thinking that it's a phantom drain on something, we bought a new $$ AGM battery thinking a larger/better battery will give us more time for the phantom to work and hopefully less "car won't start" moments. Also, I've got a funeral to go to this week and don't have time to dig into it myself until later this month.

Then walking by, I hear the HVAC fan has somehow activated when the car has been turned off. like the car has been turned off for 2 hours, the keys are nowhere near the car and you walk by and hear the fan. I think i found the phantom. Any suggestions? I started the car, then turned off again and the fan (not the motor fan, the interior HVAC fan) was still running.

Turned on again, turned HVAC system "OFF" while the car is running then turned off and it's no longer on. Clearly there is a short somewhere because it's never happened before.. anyone else experience anything like this? Recommendations?

Just to be sure:

You know it is the internal HVAC fan running because you can feel air coming out of the air vents, right?

HTH