Heated Seats

[Cobra2top]

Alright, when one seat heater works and the other doesn't, and the indicator in the EATC display does come on then it usually means one of the resistance circuits is toast in the seat that doesn't work. There are other possibilities but this is a good place to look first.

I mentioned in a post above to disconnect the battery and wait a few minutes to make sure the airbags are disarmed before working under the seats. I don't know if it is really possible to accidentally deploy the airbags by unplugging the wrong connector under there, but the diagnostic procedure is full of warnings about disabling the SRS. So take care.

The two connectors you guys want to disconnect are the 4-pin connector (C364) to the seat cushion heater and the 2-pin connector (C365) to the seat back heater.

Measure the resistance between pins 1 and 4 (the two outside most pins) on C364 component side. Is the resistance less than 5 ohms? YES - go on, NO - replace the seat cushion heater.

Measure the resistance between pins 1 and 2 on C365 component side. Is the resistance less than 5 ohms? YES - go on, NO - replace the seat back heater.

Measure the resistance between pins 2 and 3 (innermost pins) on C364 component side. Is the resistance less than 300,000 ohms and greater than 50 ohms? YES - install a new heated seat module. NO - replace the seat cushion heater.

So, get yourselves a good digital VOM and check those circuits. Let us know what you find out.

Also thanks!! I have a good VOM so I am going to dig into this week and let you know. I think I burned mine up the other day when it got pretty hot. I bet it is the resistant curcuit.

I'll report back.

 

[jrford]

Just to make it easy there seems to have been a change in mid production '03
In my FSM book for '03 there are two heated seats diagram - early build and late build.
From the looks of it early build has a module which i would guess is under the seat. No such module in late builds. . . .'04 is the same as late build '03 which i posted above.

 

[rrgone]

Just to make it easy there seems to have been a change in mid production '03
In my FSM book for '03 there are two heated seats diagram - early build and late build.
From the looks of it early build has a module which i would guess is under the seat. No such module in late builds. . . .'04 is the same as late build '03 which i posted above.

I've got an '03 FSM too, and it has no such differences listed. Your's must be newer than mine. I also have one for the '02s that has lots of early/late build distinctions. I didn't know that Ford did it again in '03! I helped a friend recently with his seat heater on his '03 EB and it must have been an early build.

Anyway, I would think that the first two steps I listed for checking seat heater resistance are still valid even for a late build '03. If you folks having problems don't have the heated seat module, than step three is obviously not valid. Here's the seat illustration I have. Part #30 is the heated seat module. Note it only has one connector. Also note that item #23 is connector C364 and it too might be different if you don't have the module, might only have 2 pins? Good luck guys. Please let us know.

 

[taygrib76]

rrgone,
could you reference the connectors that need to be tested to the diagram that you posted.

4-pin connector (C364) is #?
2-pin connector (C365) is #?

I also have a 03 EB and my drivers side does not heat, but the pass. side works fine. both show the "heater on" icon on the display when the button is pressed. there is some good info in this post, thanks

 

[jrford]

My '03 FSM is actually the wiring schematics, its the paper book.
It could be wrong. . .

 

[rrgone]

rrgone,
could you reference the connectors that need to be tested to the diagram that you posted.

4-pin connector (C364) is #23
2-pin connector (C365) is #Not shown

I also have a 03 EB and my drivers side does not heat, but the pass. side works fine. both show the "heater on" icon on the display when the button is pressed. there is some good info in this post, thanks

 

[skidoomxz99]

Alright, when one seat heater works and the other doesn't, and the indicator in the EATC display does come on then it usually means one of the resistance circuits is toast in the seat that doesn't work. There are other possibilities but this is a good place to look first.

I mentioned in a post above to disconnect the battery and wait a few minutes to make sure the airbags are disarmed before working under the seats. I don't know if it is really possible to accidentally deploy the airbags by unplugging the wrong connector under there, but the diagnostic procedure is full of warnings about disabling the SRS. So take care.

The two connectors you guys want to disconnect are the 4-pin connector (C364) to the seat cushion heater and the 2-pin connector (C365) to the seat back heater.

Measure the resistance between pins 1 and 4 (the two outside most pins) on C364 component side. Is the resistance less than 5 ohms? YES - go on, NO - replace the seat cushion heater.

Measure the resistance between pins 1 and 2 on C365 component side. Is the resistance less than 5 ohms? YES - go on, NO - replace the seat back heater.

Measure the resistance between pins 2 and 3 (innermost pins) on C364 component side. Is the resistance less than 300,000 ohms and greater than 50 ohms? YES - install a new heated seat module. NO - replace the seat cushion heater.

So, get yourselves a good digital VOM and check those circuits. Let us know what you find out.

RRGone - Thanks for the reply! I just spoke to my cousin and the resistance on the heated seat module is like 30,000 so it looks like the heated seat module is the problem.

Does anyone know where to buy a heated seat module cheap (and part number for 02 EX)?? So far, the one dealer who has it in stock is looking for $105. I tried calling RockAuto.com but they don't carry it.

Thanks again for all the help! I will keep you posted with what I find out.

 

[rrgone]

RRGone - Thanks for the reply! I just spoke to my cousin and the resistance on the heated seat module is like 30,000 so it looks like the heated seat module is the problem.

Does anyone know where to buy a heated seat module cheap (and part number for 02 EX)?? So far, the one dealer who has it in stock is looking for $105. I tried calling RockAuto.com but they don't carry it.

Thanks again for all the help! I will keep you posted with what I find out.

Swap the one out from the working passenger side to make sure before you spend $100 for a new one.

 

[skidoomxz99]

RRGone - good idea.. Question, can you get to the heated seat module without removing the seat (the car is 2 hours away from my house)?

 

[rrgone]

RRGone - good idea.. Question, can you get to the heated seat module without removing the seat (the car is 2 hours away from my house)?

IDK - mine doesn't have heated seats, don't need 'em in Tucson. The manual says you don't have to remove the seat to get to the module but you might have to be nimble to get it out. You tell us.

Make sure you get the right module as there were two used in 2002. Early-build/late-build thing. Get the part number off of one of yours before you order.

 

[taygrib76]

after pulling back my seat cover on my 03 EB explorer, i saw that the bottom element had a burned out coil, however the connection for the lower seat element is a 2 wire leading to a green 2 pin connector. The other connector apparently coming from the seat back, was a gray, 4 pin connector. This is backwards from the description above. Do i have the late 2003 model? Also where can oem compatible replacements be purchased? or will those aftermarket heating elements work well with the factory setup?

 

[rrgone]

after pulling back my seat cover on my 03 EB explorer, i saw that the bottom element had a burned out coil, however the connection for the lower seat element is a 2 wire leading to a green 2 pin connector. The other connector apparently coming from the seat back, was a gray, 4 pin connector. This is backwards from the description above. Do i have the late 2003 model? Also where can oem compatible replacements be purchased? or will those aftermarket heating elements work well with the factory setup?

That's weird. I looked again in the '02 and '03 FSMs and they both say the 4 pin connector goes to the seat cushion heater, not the seat back heater. That's what I recall seeing in a friend's '03 EB as well. What does your's look like on the other seat?

 

[taygrib76]

Turns out I have a late model 03, so there's no sensor wire in the cushion or the back ( I was wrong, 2 wires for the back as well). So both elements have a 2 pin connector. All is well now, I installed a seat cushion element today and everything works.

 

[skidoomxz99]

I wanted to follow-up on this post. I appreciate all the help, especially JRFord and RRgone. The heated seat element and heated seat module was replaced on the drivers side seat. The seat now gets warm and within spec of the passenger side OEM element. We used a temperature sensor and the passenger seat will get about 80 degrees (OEM heated element), where as the drivers side is 75 degrees (OEM replacement) after one cycle.

One last question, does anyone know why the light on the heated seat switch does not light up when turned On (on the side of the seat)?

Happy Holidays!

 

[skidoomxz99]

Also where can oem compatible replacements be purchased? or will those aftermarket heating elements work well with the factory setup?

I bought an OE replacement heated seat element from Rock Auto for like $22..

 

[rocco123]

Looking for a schematic for my '02 Limited seats. Would like to design a time delay (maybe 5 seconds) after remote starting to turn both seats on.

Any help would be appreciated. Haynes does not show much on the wiring.

 

[rrgone]

Looking for a schematic for my '02 Limited seats. Would like to design a time delay (maybe 5 seconds) after remote starting to turn both seats on.

Any help would be appreciated. Haynes does not show much on the wiring.

I just ordered one from here a few days ago. Hasn't arrived yet though. For only $10 including S&H you need it.

 

[rocco123]

Thanks for the info on the wiring manual. Will order one today. I'm sure I'll use it.

 

[twotterguy]

cobra2top:
hey man thanks for the help everything working fine now. shortened down the seat back pad till just above the problem and resoldered works fine thanks again for the resistance check info
harry

 

[nasty_north]

wow i hope i dont get an airbag in my face! glad i read up on that i would def not have disconnected the battery. but i plan on switching the switches first before i even break out the volt meter. thanks for posting the wiring diagram anyways!