Seat Heater not Heating? Here’s Where to Start
MVS Moderator Ozark Lee shows us how to fix broken heated seats on a P80 Volvo:
Here is my standard method of diagnosing seat heater problems:
Look under the seat, on the right hand side as you look at it from the footwell, and locate the power connector for the seat.
It is the large white connector with the Yellow/Red wire and the Black wires.
- You next need to locate the heater pad plugs, they are just below the front edge of the seat, they are both 2 conductor connectors. One connector is gray and the other is black.They are pictured here:
- Backprobe the red wire on the black connector and check it for battery voltage as well, the black wires on the power connector are a good ground point for the meter.If you have good voltage there it means that the thermostat and its circuit are good. If you don’t have voltage there it means that the thermostat is bad (not likely) or the wiring to the thermostat has come unplugged (more likely). The thermostat is located near the rear of the bottom seat cushion and it has a Red wire and a Red/White wire going to it. Plugging it back in is tricky and is best accomplished from the back seat and having someone sitting in the seat – that someone will get goosed a bit.Assuming that the voltage is good on the red wire next move to the yellow wire. On a normally working system you should read voltage there but it will be less than full battery voltage.
- If you read full battery voltage on the Yellow wire then the seatback heater element has burned out.
- If you read no voltage there then the seat bottom heater element has burned out.