jokerman826

I did an extensive search and cannot find anyone else with my problem. My passenger seat heater doesnt seem to want to work. I decided since i have some time off of work this week i would tackle the problem before it gets too cold. I unbolted the seat and gained access to the heater plug. While taking resistance readings i got 54 ohms and 108 ohms. So that means the elements are good. Then i checked for voltage coming from the switch while in both positions and I get 12V both ways. I know there is the occupant position sensor for the airbag but does it also work with the heater, i doubt it does but just curious. If anyone could provide a little help on this one it would be appreciated. My wife keeps complaining that her butt doesnt get warm in my car and i am tired of hearing it.

I think this may be in the wrong section. Its electrical, but also is a problem. So mods, if you deem this should be in the problem and fixes section, i have no problem with the trhead being moved.

I just got done sitting on the passenger seat for an hour. I had the heater switch in high and made sure everything was connected. During that hour, i did not feel any warmth for about 20 minutes. I couldnt determine after that hour if it was the heating element or my butt that warmed up the seat. I know it didnt heat up like it should, the seat should have gotten hot enough for me to know that it was the seat that was actually heating up since i had the switch in high. I am still getting proper readings on voltage and resistance and cannot figure it out.

Even though my numbers did not look bad, i decided to check the drivers seat. I sat in the seat and it heated up in under 3 minutes. I took resistance readings and I am getting 5 ohms on the driver's seat heating elements. So even though I thought the passenger seat numbers were not bad, I guess they actually are.

If someone could provide the resistance numbers for their working passenger seat heater it would be appreciated. I would just like a little confirmation before i go and order a new seat heater.

Deerole

I have the same issue with the pass seat but only the back not the bottom of the seat...luckily i still have warranty. once i take it to the dealer ill try to get some info for u

KN_TL

iTrader: (3)

I'm pretty sure there isn't a element in the back of the passenger seat. The occupancy sensor takes it's place.

I NEVER ride in that seat so I can't say for sure.

jokerman826

^^thats correct, there are not heating elements in the back of the front passenger seat.

My only problem is that it seams that the elements are fine but it turns out that they are not. They are not showing an open but when compared to the drivers seat, they are not right.

Deerole

^^ so the driver side back is heated n the pass is not? if thats the case i guess i dnt have an issue...but ill still ask the dudes at the dealer for u if i dnt 4get. hopefully itll get u some good info

KN_TL

iTrader: (3)

I took a look at the service manual and the continuity check is to be done at the bottom of the seat. They don't spec a resistance just that you should measure continuity.

I would assume the resistance would likely differ between the two seats because there is the seat back element in series with the seat bottom on the drivers side and not on the passenger side.

Have you swapped the switch positions to rule out the switch if one seat works and the other doesn't?

Also while looking at the service manual verified there is no element in the passenger seat back. There is a sensor to turn off the airbag in it's place.

jokerman826

Switch is fine, power gets to the heating element. I unbolted both seats and checked the continuity of the heating elements. The passenger is getting upwards of 110 ohms but the drivers is only 5 ohms. I would really appreciate if someone could check the continuity of their working passenger side heating element. Since my drivers side heater works and I get a low resistance reading and my passenger side element doesnt work and I get a much higher reading, even though it isnt bad, the only thing I can think of is that the element is bad. But I need confirmation before I go spend over $200 for a new element.

KN_TL

iTrader: (3)

I would check but there's something very different between an 04 and an 06. I just checked the cost of the element and the 04 is over $200 and an 06 is a fraction of the cost (around $78).

jokerman826

I have the 04-05 electrical troubleshooting manual. I guess they decided to change the design in 06. They did do other electrical changes to the 06 model year. but i wonder how different the heating element is from the 04-05 to the 06 model year. Hope someone can chime in on the electrical drawing from the 06 model.

I hate cars

FWIW, the seat heater has been flaky even when the car was brand new. Sometimes it will heat up right away and stay hot. Sometimes it takes 10 minutes. Sometime it barely gets warm. Have you tried it in the low setting? I know the logic used was weird but something about it was not meant to be run in high for very long.

There's a thread on this problem with a resolution but it's buried deep in here. I would go at least a couple years back in the search.

I would also imagine they don't run 30a through the switches so there's probably a relay somewhere.

jokerman826

I tried it in the low setting but not for very long, maybe a min or two. I had it in low be accident, when i realized that it was in low i switched it to high. I will go check it in low here in a few min. I know my drivers seat heats up a good amount in 2 or 3 minutes.

There is one relay that feeds both switches. It looks like it gets split after and not at that relay. But since i am getting the proper voltage at the heating element plug then i doubt its the relay.

I will search again and see if i can come up with something this time.

jokerman826

Looking at the service manual diagram and not the electrical T/S diagram. There is a breaker and thermostat in the high circuit. So I am going to do what IHC suggested and try the low circuit for a little. I will come back with my findings.





I just finished testing the low circuit and after sitting on the seat for 20 minutes I got no sense that the heating element was working. I have attached the diagram for the circuit with this post.The diagram shows that the high circuit has a thermostat and a breaker. I feel so stupid about this problem, I should be able to figure this out

I am just going to take the whole damn seat out and pull off the cover to look at the element directly.

EDIT: (So I dont have a crapton of posts in a row, LOL)Just looking at the diagram again, when the switch is set to Low, the heating elements are out into series, which increases resistance, causing a low heat output, but when the switch is placed in high, the elements are placed in parallel which lowers resistance, in turn causing a higher heat output.

gt1

According to the diagram, even with the bad occupancy switch, heater still should work on the Low settings. And if the occupancy switch and at least one of the heater elements are good, you should get heat on High setting. What puzzles me is the 54 Ohm resistance reading. Given the 12V supply it results with less than 3W of the output power, which seems way low. To give you some baseline, I have electrically heated motorcycle clothing. My gloves use 25W and the jacket is 90W.

jokerman826

I am still searching through the threads. But i got the seat apart to check out the actual elements. They look perfectly fine. The resistance is the same as i got before. I checked out the resistance direcly on the thermostat and the breaker (which lie directly under each leg) that is with the heating element and they read minimal. So i know that they are sending power through to the element.

So this is whats I have found so far. The elemet has good continuity approx 55-110 depending on high or low, the element gets power from the heater relay and the breaker and thermostat for the element are good. I have checked all fuses and did not see any damaged ones.

Whiloe typing this i decided to stop and do one more check. I grabbed some 16 gauge power wire i have laying around and layed out approx 35 feet end to end. I connected it to the plug coming from the car on the high side. Lo and behold, the damn wire heated up. The wire had approx .3-.5 ohms of resistance on it. At first i tried a 9" piece of 16 gauge power wire and it blew the fuse instantly.

So my current theory is that the element is bad, even though i am not showing "bad" continuity.

What is the difference between the 2004 heating element and the 2006 heating element. I wouldnt mind getting the cheaper one if it would work.

jokerman826

the switches that are in the seat are a thermostat and a breaker (the breaker is the back-up incase the thermostat doesnt open the circuit.

jokerman826

I found this very old thread that talks about the passenger seat. One post mentions that the 2004 seat doesn't have a channel for the seat to fit properly. Click HERE to see what i am talking about. It is post number 5. I was wondering how accurate the post is. Mine is a 2004 and my seat cushion has the channel running down the middle of the seat. I dont think that the seat cushion has ever been replaced. I believe that the poster of that comment was confused on the model years.

I would really like to know the difference between the 2004 and later passenger side seat heaters and why the 2004 one is $160 more than the 2005-2008.

Kirk3272

iTrader: (1)

A little off topic but might be useful. I just added leather seat covers to my SUV and used some cheapo seat heaters off of Ebay. They work great and are about $40 for a PAIR(per seat). Thinking of getting two more pair and add heated seats to the rear of the TL.
Pair is, one for bottom one for back.

I do not know these folks and mine have only been installed for two weeks.

http://www.ebay.com/itm/260894212034...84.m1497.l2649

jokerman826

Thanks but i dont trust things like the seat heaters unless they are OEM. Its a safety issue for me.

gt1

Have you tried to measure resistances of the working seat?

jokerman826

Yup, it was in an earlier post, 5 ohms and 10 ohms approx

jokerman826

I got ahold of some low voltage two wire twisted 30 awg. I have decided to attempt to rewire the seat heater myself instead of paying $240 for a new heating element. Worst case scenario is that it doesnt work and all i lost was a few hours of my time. I will post an update when i start this fix.

jokerman826

I just did the rewire on one of the elements and my resistance is too low on the wire. I should have a mininum of 5 ohms and I am running just under 1 ohm. My guess is that all i need to do is put a resistor in the curcuit to drop the current so that the watts will not be too high. The resistance level that i have allows the element to heat up too much in low setting and the element starts to smoke. So I am going to find a small resistor to put into the circuit.

just figured out resistor wont work, the wattage for the heater would be to great for it.

DejaVu85

Did you ever find out if we can just buy the 06 heating element and use it in our 04 TL's?

I think I have the same issue as you, my passenger heated seat stopped working a few days ago.

07TL-S

I'm having the same issue in my TL. So is it safe to say that replacing the element would fix the problem? ..Is it easy to replace it?
Anyone have the part # for a 2007 TL-S?

jokerman826

I figured out that in order to replace the wire in the element you will need some special wires that have more resistance than a copper wire. But i have not yet found out if the 05+ element would fit the 04. I should look into it some more. Maybe purchase it and then if it doesnt work put it up on the black market. That wont happen for a few months, I need a little extra cash.

njkode

My gf always complains that her seat never gets warm. I have an 07 TL-S, I'll have to check the resistance. As well as sitting in my seat to see if there actually is a problem.

joeytheswede

O7 TL-S owner here as well. Seat heater not working on both sides. Took it to the dealer and was told both seat elements were bad. I'm getting it fixed under warranty. I'll inquire about the compatibility of the various years and report back to you. And yes, the passenger seat lacks heating elements on backrest portion of seat.

J35A8_Party

Is the driver bottom supposed to work? I only have back heater and nothing works on low. Passenger side is fine.
07 TLS 6MT

jokerman826

Driver bottom is supposed to work along with driver back. I still ahvent come up witht eh extra money to see if the different model years are compatable with the 04.

canuckshawd

if this thread is still being monitered...my 2012 tl sh-awd has the same issue (brand new car) no heat to the passenger seat back...asked Acura and was told this is by design...