2002 deville drivers heated seat

[gone12]

checked heat elements and relay box by switching to right side

when i put relay box back it does not work I could hear it klick every time

I t goes from high ,med ,and low I t does not hold relay on to make power

what should I check next

High,med, low light up.

I notised that when i put it on right side it will klick 1 time only that will indicated relay is on for power

and will make heat mind u relay is good because i switched back were do i look?

[Cadillac Jim]

My money is on the temperature sensor in the left seat cushion (see below). There are some OBD codes that check out the heated seats circuits, so you might want to run your codes and post them here.

I see from the title of your post that you have the Deville, not the 1992 ETC in your profile. I'm going by the 1997 FSM schematic on pages 8A-143-0 and -1; your car is probably the same but you should be aware that this information is from the FSM for another model year. Your car may very well differ. In particular, the 1997 FSM shows only OFF, LOW and HIGH and there is no MEDIUM position.

In the trunk compartment fuse block there are three fuses: CONSOLE FUSE 10 Amp, HTD SEAT L Fuse 10 Amp, and HTD SEAT R fuse 10 Amp. That's the first place to look, once you've established that the heating elements in the seat cushons *and* the seat backs are OK. To test both the heating elements for either seat, unplug the relay and check for continuity between the RED/WHT wire and ground. If it's an open circuit, either the seat or back heating element is bad, or one of the wires hooking them up is open.

In the 1997 FSM the relays are part of a module. The terminals on the connector are labeled A through F. Wire colors are, in order, RED/WHT, PNK, BLU, ORN, YEL/BLK, and BLK. If your wire colors agree, my information probably applies to your car, except for the switch MED position which shouldn't affect the module (except possibly its software).

The fact that your LED lights up shows that the Console fuse is OK and that at least part of the switch is good, and that the seat ground is OK for the switch. The other part of the switch has resistors (200 Ohms for LOW, 310 Ohms for HIGH on my schematic) that you can check between terminals B and D on the switch (PNK and BRN wires; unplug the switch before applying the Ohmmeter). My guess is that this connection goes through the module to the YEL/BLK wire that goes to the temperature sensor and that the module uses the voltage on this wire to turn the relay off and on, so check the resistors and make sure that all three of them are there and that they are in the range of 100 to 500 Ohms. Also make sure that the PNK wire is OK and has good connections on both ends.

On the seat cushion there are four wires, A is RED/WHT, B is BRN and goes to the seat back, C is YEL/BLK and D is BLK. The relay could be dropping out because the temperature sensor in the seat cushion isn't working. Make sure that the BLK wire has a good connection to ground, that there is continuity in the temperature sensor where the BLK and YEL/BLK wires connect to terminals C and D, and that there is a good connection on the YEL/BLK wire on both the seat cushion and the relay terminal E, and that the YEL/BLK wire isn't broken or shorted. This is probably where your problem lies.

[rockfangd]

also bear in mind they dont work unless you are sitting in them. I found out the hard way lol

[gone12]

the car is a 2002 deville

relay is under the seat relay is good fuse is good it should not click eery time u switch from high to med low it should click and stay on its not

were to look ?

[Texas Jim]

the car is a 2002 deville

relay is under the seat relay is good fuse is good it should not click eery time u switch from high to med low it should click and stay on its not

were to look ?

I hate to be picky... but your posts are kinda hard to read.

Is it possible for you to use a little better grammer and maybe a little bit of punctuation??

Maybe something like this ???

The relay is under the seat. Relay is good and the fuse is good. It should not click every time you switch from high to med to low.

It should click and stay on, It is not doing that. Where should I look?

[Cadillac Jim]

Usually when heated seats stop working it's because of a broken wire in the seat heating element, which is a hard fix because the dealer will want to replace the seat or seat cushion, and they can't get one. DIY people take them apart and replace the wires; there are detailed posts of that process here. The idea here is to look for the simple, cheap fixes first before going to the difficult or expensive fixes. This is very important because you don't want to spend money and/or time and find out that you haven't fixed the problem, then find that it's a fuse that you didn't look at first or a $4 relay or something. Please bear with us; there is a lot of experience and know-how here.

There are three fuses involved with the seat warmers. The one that operates the relays and lights is separate from the ones that operate the heating elements. Check the fuse marked HTD SEAT L. It's in the trunk along with the other two fuses, HTD STEAT R and CONSOLE FUSE, which we know are good because the passenger seat heater works and the lights on the switch work.

You can check out the seat warming wiring very quickly with an ohmmeter, even the $15 units for Radio Shack or an auto parts store; just don't use those to check wiring still hooked into the car because they may not be safe for the electronics. The way to check the seat wiring is to unplug the wiring harness at the seat cushion and seat back, and to check the resistances in the seat cushion and seat back.

There should be a reading of a few Ohms in the seat cushion wiring between the RED/WHT and the BRN wire. If it is infinity Ohms (an open circuit) then the seat heating element is bad. There should be a reading of a few Ohms in the seat BACK wiring between the BRN and BLK wires. If not, the heating element in the seat back is bad. Unless both of these heating elements are good, neither will work because they are wired together.

There should be a reading of a few Ohms between the YEL/BLK and the BLK wires. If not, the temperature sensor is bad.

Your heated switch has two separate parts, the one that operates the lights and relay and the one that operates the module. It's possible that one side of the switch is working but the other is not. If the HTD SEAT L fuse is good and the seat and seat back heating elements check good, and the temperature sensor checks good, come back and I can walk you through the troubleshooting process in the FSM, or someone else that recognizes your problem or has a model year 2000 FSM can chip in.

FWIW, in the 1997 model year schematic that I'm looking at, the temperature is regulated by the relay/module by turning the 12 Volts to the heating elements off and on, like a house thermostat regulates the house temperature by turning the furnace off and on. So, the relay will click occasionally as this is working.

[gone12]

Your heated switch has two separate parts, the one that operates the lights and relay and the one that operates the module. It's possible that one side of the switch is working but the other is not. If the HTD SEAT L fuse is good and the seat and seat back heating elements check good, and the temperature sensor checks good, come back and I can walk you through the troubleshooting process in the FSM, or someone else that recognizes your problem or has a model year 2000 FSM can chip

Is this for 2002 devile dhs?

[Cadillac Jim]

That information is from my 1997 FSM. It's probably accurate for your 2002 DHS but someone with a 2002 FSM could verify this or make corrections.

Separating switch functions for power and for indicators is very common. If the switch handles only signals to a computer module, only one section makes better sense. Using a double-pole switch is almost universal practice when the switch controls both indicator lights and power to the accessory. So, I would expect that the information from my 1997 FSM is accurate.

But, five years is a long time. Please, someone with a 2002 FSM, chip and and verify this.