OEM Heated Seats Working Intermittently

[Silentnoise713]

I notice the OE heated seats work in a very funky manner. Sometimes it would work, other times it would not. Sometimes the Pass seat works, other times the driver side works, and on rare occurrences both work. I though it was due to the heating elements going bad, then I notice something in the OM that’s puzzling me.

https://www.mymazda.com/MusaWeb/pdf/manuals/2012_MZ5_OM.pdf#page=29 Page 29/440.

Use the seat warmer when the engine is
running, and do not continue to use it for a
long period of time.
The temperature of the seat warmer cannot
be adjusted because the seat warmer is
controlled by a thermostat.

^I’m confused as what the 2nd lines means. When working it does not turn off -unless I have not reached the breaking point of too hot (it get’s pretty uncomfortably hot). It reads as though this thermostat controls if the heating elements can be turn on, even if you flip on the main switch. If so, this is very misleading b/c the switch is illuminated. If so, would a faulty thermostat lead to this funky behavior and where would it be?



Looking at seat the diagram, I don’t see anything that’s identified as a thermostat. Is it using some other thermostat? I’m stumped. Anyone have a lead? How are your heated seats working?
http://www.jimellismazdaparts.com/s...odel=14357&modelYear=2008&ukey_category=20289

 

[njaremka]

when we first brought our 2008 home, we thought something was wrong with them, too. i would expect them to turn on, get warm, and hold a set temperature. but it seemed like they would cycle hot-cold-warm-cold-hot-warm-etc... talked to the dealer about it, and he said it was normal for them. never could figure it out. now, 6 years later, and they still work exactly the same as they did on day one. i never did like the way they controlled the heat, but they seem to work fine when you click them on after the car has been sitting all night in the cold. however, compared to the heaters in my 2011 mx5, the mazda5 seats still suck. my mx5 has the switch with 5 levels of adjustment, which seem to work much better than the simple on-off switches. i wish our mazda5 had a similar set up.

 

[Silentnoise713]

Thanks for confirming the wacky behavior! Anyone else have a GT and issues with their seats or are they working fine for you?

 

[X-Tanker]

My seats would also cycle on and off. I would have preferred them to stay on until I decided to turn them off. Don't have to worry about it anymore since my driver's heated seat quit working. One day it go extremely hot to the point it was very uncomfortable. Turned it off, waited 5 minutes, turned it back on and again it got very hot. Turned if off again, waited a few minutes, turned it back on and nothing happened. Hasn't worked since. It's out of warranty so dealer wanted like $75 just to diagnose the issue, which I did not do.