For many years, my seat heat would not work. Both sides would fail after a few seconds of powering the switch. I read many threads about the seat heaters shorting out. I found it hard to believe because I was having the same problem on both sides. My truck is my DD and I drive solo. The passenger seat has had little use. I regularly tried to turn the seat heat on but to no avail. Last week we had a near monsoon and I unfortunately left my driver's window open. My truck looked life a submarine that left a hatch open. My horn was blaring and I had to pull the lead off the battery to stop. It rained for days and I could not dry the truck. When the rain quit, I placed a large box fan in the truck and left the windows open for a few days. After drying, I reconnected the battery and except for a slight odor was back in business. It was cold the other day and I was in the truck. As I often did, I selected the seat heat knowing it was going to fail. I could not believe it, my seat heat now works perfect on both sides. Go Figure!

 

That's pretty interesting. I'm not sure it was worth a flooded cabin, but at least something positive came from the unfortunate event. Congratulations!

I just recently fixed a rear heated seat in my Charger that would light the switch for about 2 seconds when pressed, then turn off. The diagnostic code indicated an open thermistor. I removed the seat bottom and confirmed no reading across the wires for the thermistor. Rather than buy a whole new heated seat bottom I opted to pull the covering and installed a new 10kohm NTC thermistor that cost a whopping $0.12 ($12 for a 100 pack of assorted thermistors). Now the seat is working like it should again.

-Rod

 

How did you pull a diagnostic code for the thermistor? Do you remember the ohm rating for testing the thermistor? I got four days of seat heat and now it's back to 2 seconds on then off.

 

I don't remember if I pulled the code using my Autel MS906BT or through AlfaOBD. The sensor is a 10k NTC thermistor, so 10 kohm at 25 degrees C (~ room temperature). Pasted below is the resistance table.

-Rod


Dodge Charger heated seat thermistor resistance table.

 

Thanks Rod. That's not in my inventory. I understand what you are saying about the thermistor going bad in one seat and you replaced it. I have a difficulty that the thermistors in the driver's and passenger's seats went at the same time. As I said, the passenger seat is never really used. I'm pulling the driver's seat to change the foam and upper and lower seat covers. Will I see the thermistor and be able to test it out? I have a Fluke multimeter and know which end of the test lead to hold. It's either that, or I'm going to regularly water my seats.

 

The thermistor is likely embedded within the seat heater pad and not necessarily obvious or easy to see. The wiring however should be pretty easy to test if you're able to determine which color wires are for the thermistor. There's probably only a thermistor on the bottom seat, and there may be 4 wires to the seat and only two that connect to the seat back. The two wires to the seat back hopefully match the color of the two wires they plug into and two of the wires for the seat, which should make it a pretty safe bet that the other two wires are for the thermistor. If the resistance across those two wires is essentially an open circuit, then you either have a corroded connection from the water or a bad thermistor.

-Rod