Heated frt seats Fault

[NBZ83]

Hi folks, both front seats don't heat. When the switches are on the red light doesn't come on either. Any common faults I should look for first of all? TIA 😊

[360beast]

Check the fuse and then try working the switches back and forth. I would also remove them and spray contact cleaner in and around them and work them back and forth again. The switches are a known weak point, my driver's one needs turning on and then I have to push it even further to get the light to come on and then it will work, I've been meaning to sort it for ages and now the cold mornings are here I definitely need to sort it.

[SnineT]

Stick your mince pies under the seat to check the connectors aren't disconnected, a clumsy foot from a passenger behind can make this happen. I think 360 has kinda covered this anyway but just in case and before you start pulling things apart.

If none of that works you will need to check the seat plug for power, if it's powered ok then it's the pads in the seats but having both fail at the same time is unlikely which moves you back to fuses and relays before switches.

Given the cars age I'd say it's likely they've died of old age and I've had them die on much younger cars.

Final thought is your battery is weak and the car is isolating things out to save CCH if Volvo were making the cars that way that long ago.

[griston64]

As Luke said it's just sticky switches. Very common on pretty much all 940's.

I removed that panel and cleaned all up and they worked fine

My other 940 that I broke was the same as was my 740

[360beast]

Originally Posted by SnineT

Stick your mince pies under the seat to check the connectors aren't disconnected, a clumsy foot from a passenger behind can make this happen. I think 360 has kinda covered this anyway but just in case and before you start pulling things apart.

If none of that works you will need to check the seat plug for power, if it's powered ok then it's the pads in the seats but having both fail at the same time is unlikely which moves you back to fuses and relays before switches.

Given the cars age I'd say it's likely they've died of old age and I've had them die on much younger cars.

Final thought is your battery is weak and the car is isolating things out to save CCH if Volvo were making the cars that way that long ago.

You would have to have bendy feet like the wicked witch of the west to get your feet under 940 seats let alone far enough forward past the heater ducting to disconnect the plugs.

The 7/900 seat heater switches are a well known weak point, I'm yet to see anything other than a switch that needs a bit of exercise to get working again. I'm sure there have been failed heating elements or blown fuses but I've been around these cars for 4 years now and never seen anything other than the switches at fault.

[TonyS9]

yeah the contacts get burnt and need a little cleaning, or you can turn the contactor around and use the fresh unused end.

They are pretty easy to take apart, here is me sounding silly on a video lol

https://www.youtube.com/watch?v=m9hB82crt2k&t=1s

[NBZ83]

Much appreciated....Will get all these tried folks👌. With the current price of heating me and the wife will be sitting out in the car rather then house,when I get them working 😁

[Laird Scooby]

A couple of other things to throw into the mix, firstly some cars had a thermostat on the seats so that if ambient temperature was above 10C (this figure varied with different years for some odd reason ) even with the switches on and the tell-tales showing in the switches, no heat was delivered.
Second is that the bulbs in the switch tell-tales may have failed, if you're good with intricate work and a soldering iron, they can be replaced with wire-ended 12V grain of wheat bulbs from ebay or even with a 3mm red high brightness LED and a 680 Ohm resistor.

Also worth checking the fuses, most have fuses in the main fusebox and some models also had a fuse on the seats themselves.