Hi guys, well I have had a few dead batteries going to start the car in the morning. I've owned the car for about 2 months now. I bought it and put a stereo system in it about 2 weeks after I bought it. As well as replaced the fuel pump/ sending unit, and wheel bearings, and 02 sensor. I am having a problem with the driver heated seat not working.

So i've been measuring voltage in the mornings after it sits overnight. Some times it's down to 11 volts or a bit lower. I hooked my meter up and did a parasitic draw test by running my meter in series through the cars negative terminal and battery, and found it was pulling about .32 amps which sounds about right? I figured I would hook it up and find something drawing an amp or so and be able to pull fuses until I found the problem, but that isn't the case here. So i'm not sure what to do next? Any ideas? I tried pulling my radio fuse overnight, but the battery still drops to 11 volts in about 8-10 hours. The alternator is working as it should, i've tested that. I just don't know how to trace this down from here?

 

Sounds like you might still have a draw. As little as .25 amps will drain the battery. Heated seats draw high amps. and there could be a short cutting in and out. Try disconnecting the fuse or relay for the heated seats.

 

Wouldn't the key have to be to the on position for the heated seat to draw any power though? It's definitely got problems, I bumped the switch to low by accident the other day coming home from work and the seat lit me up. Crazy hot by the driver side bolster to the point that I thought it was going to burn me and I could smell some type of electrical burning. There is a heated seat fuse I believe, as well as a relay for it under the seat. Maybe i'll pull them both and see overnight.

Are you saying that the car should draw less then the .32 amps that I was seeing? Or are you saying maybe it's intermittently trying to turn itself on and i'm not seeing it when I do the parasitic draw test? I was told that .32 is pretty much normal. Anything above 50 milliamps and I should be concerned.

 

I'm no auto electric Wiz, but I've been told .25 causes problems. And yes, I'm saying the problem could be intermittent. The wire to the seats is parallel in the circuit off the BCM which is always hot. Do you have a schematic?
Have you seen this tech guide?: https://montecarloforum.com/forum/fw...-jimbo7-25224/
If your seat is overheating it might be the Thermal Resistor.

 

Maybe I was lead to believe some incorrect information if even .25 can cause problems, I just didn't think that was enough to drop the voltage down a whole volt in 8-10 hours. I still don't see why that would turn the seat heat on with the switch being in the off position and the key off. I suppose that makes sense if the bcm is always hot. I do not have a schematic. The link posted has no pictures but I followed a similar guide. I took the cover off the back of the seat, and I found no wires that looked damaged, melted, or burnt, so I put it back together.

The problem is with the seat, is that more times then most, I flip the switch on, and I get no heat at all. Other times it randomly turns on and when it does it just gets insanely hot. I've tried switching relays from the pass seat and still had an issue with driver seat so I know both relays are good, and fuses are good. Was going to swap switches, but the connectors on them are different.

I assumed when I pulled my seat apart that I would find a burnt wire for sure but I saw nothing wrong. I did see the little black button thing which is apparently a thermal resister from what you're saying. Sounds like that's likely messed up as well.

Where to go from here now?

 

Here is a picture of the wires I found in the seat

 

Here's a thread that might help trouble shoot the heat seat problem:
https://montecarloforum.com/forum/mo...er-side-24461/

 

Are you still thinking that my amperage draw is due to the heated seat then? Or should I focus elsewhere? I would like to figure out why the car won't start some mornings before I worry about the seat, unless that's the culprit

 

Did you have issues before you did the stereo install? If you did any kind of wiring (a sub, amp etc) I'd be checking that setup first.

 

I only had the car for 2 weeks before I did the stereo install, but in those two weeks the few times I did drive it, there was no issue at all with it starting for me. That's why I went after the radio fuse for my first test overnight. Pulled the 15amp radio fuse, and the voltage still dropped overnight. I would have thought doing the parasitic draw test it would have revealed something pulling amperage if the subwoofer amp was turned on. Maybe I should do some more investigating into that somehow?