Seat Heaters not working

[Zack1978]

Hi everyone,
The seat heaters are not working on either front seat. The only thing that happens when you hit the heat switch for the first time, the light will flash for a second or two, then go dark. I assume that there is power to the heater, since the light will falsh quickly. IS there know problems with the seat heaters? If so, what might be the fix?


Thanks,
Zack

 

[GreenGuss]

Hi Zack,

I'm searching through these forums to resolve this exact issue. For me, the buttons on both seats work, but the heat does not. When I turn on the headlights with the seats on, the seats shut off. If I turn the car on with the headlights on, the seat buttons turn on only for a second. My hunch is that I have a ground issue given the age of the vehicle (it's a 99), and that everything else with the heaters appears to be fine. I took the drivers seat out, tested the element (which I've already fixed twice), took apart the controller to look at the circuit board and it was fine. So, I put the seat back in the truck and noticed this strange connection between the headlights and my seat heaters. I've had issues with poor grounds causing weird issues before, but not on Explorers. 11 years ago I had a 1990 Caravan that had issues with the brake lights sticking on, but only when the headlights were on and only occasionally. The ground for this circuit was under one of the screws for the windshield wiper motor and once cleaned up, the issue was resolved.

Let me know if you run across anything, I'll do the same.

Goodluck!
-Jared

 

[GreenGuss]

Update:

Yesterday I stumbled across a site that has what appears to be a seat heater diagnosis spec posted by a Ford Tech that I used last night to run circuit tests. The instructions are a bit confusing, but I figured out the tests after a while of re-reading the instructions a few times. My results - the elements are perfectly fine, the controller appears to be fine, which are results I expected given that both seats aren't working. I'm now hoping I can figure out where the black ground wire finally is anchored. Odd that everything else on the seat works but the seat heaters though. Stay tuned.

Link to site:
http://www.justanswer.com/ford/5resz-ford-explorer-limited-2000-ford-explorer-ltd-driver-s-seat.html

I'm not crazy about putting in an aftermarket setup, but I'm seriously considering it...

-Jared

 

[dpcaver]

Driver Seat Heat Inop

I have a similar issue...the passenger seat heat works, but the drivers does not. Switches light and fuses are good, so finally took it in to the local Ford dealer for testing. $92 later, I was told the driver elements are bad and it is a $600 fix. Found this site after the fact, so looking for any ideas or ways for this to be a less expensive DIY project.

 

[GreenGuss]

I have a similar issue...the passenger seat heat works, but the drivers does not. Switches light and fuses are good, so finally took it in to the local Ford dealer for testing. $92 later, I was told the driver elements are bad and it is a $600 fix. Found this site after the fact, so looking for any ideas or ways for this to be a less expensive DIY project.

When my drivers seat first went out (years ago), the element had a bad connection due to wear. The elements are serviceable with solder and a soldering iron (as well as wire). It's almost always the bottom seat cushion element that goes. There are 5 bolts to remove the seat from the vehicle (not difficult), remove the electrical connectors, and the seat is out. To remove the seat cover, first remove the track (4 bolts), then work the cover loose. There are many metal camps holding the cover to the wire seat frame, needlenose pliers work good to remove these. When reassembling, it will be much easier to use plastic zip ties. Work the cover off over to the side with all of electrical controls, it's easier to leave that side assembled. After the cover is off, you'll see the heating element, which is sandwiched between fabric. Pull appart the halves of the fabric to reveal all of the wiring. The issue might be very obvious, as in you have a burnt wire segment, or it not be, like there is a poor connection at one of the solder points. For me, my issue was not obvious. I resoldered everything, and it worked great. If you want to make sure that you've actually fixed it, re-attach the track and set the seat in the truck and turn the car on without reattaching the cover. That way you can be sure you got it.

I've done this procedure twice in the past. This time my issue is very odd. My passenger and drivers side seat will work but only if I don't press the brake pedal. As soon as I do, they shut off. I thought it was my headlights that turned them off, but the issue appears to be related to the taillights/brake lamps. If I don't hit my brakes, like in the garage idling, the seats work, but weakly. I haven't had time to fuss with them any more recently, though I still plan to. I still believe I have a ground issue. I've cleaned a few under the hood already without success.

Goodluck with your project!
-Jared

 

[Zack1978]

Mine is very odd......The first time that you hit the seat heater button after the car has been started, the light will flash on for just a few seconds, and go out. The light will not flash on at all again, until you shut the car off and start it again. Then if you hit the button, it will flash on again for the few second cycle. Any ideas?


Thanks,
Zack

 

[GreenGuss]

Zach, your issue sounds like mine. Here is the sequence of what happens. Turn the car on, hit the seat heater switch (both driver and passenger). They'll stay on until I do one of the following:

1. Hit Brakes: sometimes it isn't the first time, or second time, but they (both) definitely shut off at some point when I'm braking.
2. Headlights are turned off, and I turn them on.

If I try to turn them on again after they have been shut off by either of the above circumstances, then they will flash on for a fraction of a second and turn off only the first time after they've been shut off. After that initial try, then they are just off, no flashes.

I took the Ex to the dealer this past week to have a few things fixed, and I wanted the seats fixed as well. They couldn't find the issue and quoted me $470/seat to repair the heater elements. I'm 95% sure the heater elements are fine, I've checked the drivers side and it has a fully-functioning closed circuit. I haven't checked the passenger side, but why would that impact the drivers side when only it is being used??

Anyway, I've had enough digging around. Too much to do to dink around with them anymore. I'm having aftermarket seat heaters installed this week. $325 for seat pad and seat back heaters on both seats, (includes labor) HI/LO setting and lifetime warranty. Sold. Figure I'll have this for another 3 years or so, or as long as it's reliable, so it's worth it to me.

Sorry I don't have anything good to report on my own success with this. If you end up figuring it out, please post your story. If I knew where the ground was for that circuit, that is where I would start and then would work back from there. Have you tested your elements to make sure you have closed circuits?

Goodluck,
-Jared

 

[rabbit91]

my drivers side doesn't work but the passenger side does. the heated seat light comes on when pushed. I have to remove the seat and salder the where there is a poor connection? maybe me obvious might be not ?

 

[waren]

been surfing this site for years ... great resource. Hoping someone can help me out with this.

Zack did you ever get your seats working? I have the same problem buttons light and then go out ... no heat in either seat.

http://ww2.justanswer.com/uploads/mi/Micharoe/2013-05-18_020607_1998_explorer_heated_seats.gif

the most obvious thing would seem to be a problem with the 30A fuse. I checked and the fuse is good. I will check for a broken wire but seems unlikely. trouble shooting the modules seems like a dead end because both seats are doing the same thing and the modules aren't connected to each other.

 

[waren]

Found the problem. There is a splice S312 I believe in tha passenger rocker/sill loom that sends power to the driver seat heater. The splice was was badly corroded causing resistance dropping the voltage to less than 5 volts. Replaced splice voltage drop is gone.

 

[Jason_pike14]

I had the exact same problem, with the seats turning on for a brief moment then shutting off. Happened on both seats. Checked the wire loom in the passenger kick panel / rocker and sure enough the lt bl/wh wire was corroded just as warren described. Replaced the splice and the seats are again functional.

To verify before tearing the witing apart you can test the voltage at the heated seat connectors where they plug into the modules. Under both seats from behind you will see the lt bl/wh leads. Using a volt meter you should be getting approx 13.9V. If it's under 13V, 90% you problem is coming from the splice in the kick panel. It should be quite obvious once you remove the tape as there will be green corrosion seeping through.

Good luck and enjoy!

I can upload an image of the schematic if someone can tell me how to upload photos...

 

[ilievdh]

Driver seat heater element was broken. I've fixed it soldering the broken heater joint with heater wire from my old Volvos seats. After the fix, the same problem like Zack1978 happened. I'll try to remove the seat and inspect and fix the S312 splice, but there is one question about my safety in my 2000 Explorer limited. If one splice can lead to malfunction in the heated seats, are there splices in the wiring of the side airbags that are integrated in the seats?!

 

[ilievdh]

Today I've tryied to check the S312 splice, but I can't find it.

Where exactley is the S312 splice?

http://docslide.us/download/link/10112751-2002-explorer-diagrams
Says "under the centre console", buth there is nothing under my centre console, just the carpet.

 

[ilievdh]

Finaly I've found the splise S312. It was so corroded, that when I have cut the tape, the splice just broke in to pieces. I've cleaned the wires with a knive and soldered them. Now the driver seat heaters are working. I suppouse that the heater element in the passenger seat is broken and need some repair work. Thank you all for the advices!

 

[haas_chris]

ilievdh: You mention that your driver side seat was the culprit and you fixed it with the S312 splice, in the picture below it appears to me (Maybe I am looking at it wrong) that you have the passenger side taken apart. Is the splice you fixed on the passenger side or drivers side? If it is on the passenger side does it control the drivers side? I am having a issue with my drivers side heated seat and just trying to gather information before I start digging into the problem.

Finaly I've found the splise S312. It was so corroded, that when I have cut the tape, the splice just broke in to pieces. I've cleaned the wires with a knive and soldered them. Now the driver seat heaters are working. I suppouse that the heater element in the passenger seat is broken and need some repair work. Thank you all for the advices!

 

[haas_chris]

Sorry for the double post back to back,

My issues I am having with my drivers side seat heater follows some of what was covered but the more I am thinking of it I have an additional symptom (from last year). I recall that last year when the heater was working the auto shut off (thermostat?) stopped working on the drivers side. I would turn the seat heater on and the driver side would get VERY hot, I would have to turn it off or it would be uncomfortable. Previously, the seats would warm up but seem to automatically shut off to keep the temperature warm not hot. Anyone run into this symptom?

 

[ilievdh]

ilievdh: You mention that your driver side seat was the culprit and you fixed it with the S312 splice, in the picture below it appears to me (Maybe I am looking at it wrong) that you have the passenger side taken apart. Is the splice you fixed on the passenger side or drivers side? If it is on the passenger side does it control the drivers side? I am having a issue with my drivers side heated seat and just trying to gather information before I start digging into the problem.

The splice is on the passenger side. It is 3 way splice. The power in, and the power outs for the driver and the passenger seats. I had problems with both of my seats. When the power switch for the heating don't light on, there is a problem with the power supply, or the controller. If the switch lights on and seat don't heat - its broken heater element, or connector (most cases heater element). I've managed to restore the power of the both seats. The heating elements was broken too. It's possible to be repaired, but the solution is very temporary, because it will last only a few months. My heating seats are broken again. This time I'll replace the heating elements with a universal ones and I''ll transfer the sensor from my old ones.

 

[clynnic]

Can someone please provide a picture of where the heated seat control module is in a 2011 model? I have searched under both front seats and nothing.

 

[Brem95]

Can someone please provide a picture of where the heated seat control module is in a 2011 model? I have searched under both front seats and nothing.

This is the wrong section. This specific thread is for gen 2 explorers.