2 Wires into Bottom of Heated Seat

Post by **akitawagon** » 13 Nov 2006, 21:05

ooops!

You may have remove the seat to access the thermostat (as MadeInJapan mentioned above) if that's where the wire disconnects are.

Post by **MadeInJapan** » 13 Nov 2006, 21:18

Most people can reach in and pull it out of the seat, but I would guess that every one's situation is a little different and also depends on where the shorting wire might be.

Post by **Ozark Lee** » 13 Nov 2006, 21:25

These wires that break, by the way connect up under the seat to a round disc which is actually the thermostat to the heater.

Great information. I bought a seat cushion from Dmsee over on VSP and noticed the round switch imbedded in the cushion. I figured that it was a pressure contact so as to not turn on the heater if no one had their arse parked in the seat. Schematically that made sense as well as the entire seat heating system is a series circuit. 12volts hits seat heater on/off switch which flows to the thermostat which flows to the seat bottom and then the seat backrest before it goes to ground. The pressure switch concept made sense since - (why would you want to heat an empty seat?) - but the thermostat makes sense as well.

I'm still confused as well about the passengers side working on Svenska's car with the Red/White wire cut as that is one of the thermostat wires which feeds the power to the rest of the seat heater circuit. Was there some other ghetto engineering that shorted the red/white wire to the red/yellow wire on the larger white connector? Shorting those two wires bypasses the thermostat which would make the seat heater work if the thermostat is bad yet the heater coils are OK.

????

...Lee

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 13 Nov 2006, 22:56

Hey Guys, Thanks for all the great information. I am not 100% sure that the pasenger side works as I am always in the drivers side. My wife thinks it does but I think it would be hotter and she would know it works. Thus I will be investigating and there should be no loose wires. I have to pull my car out of the chilling rain and haul a seat out. I will let you know what happens.

Thanks Again!

Post by **KC95Turbo** » 14 Nov 2006, 06:47

Hey I just thought I would give you some hints since I just went through this a couple weeks ago. It was very easy to fix. First move the seat all the way foward and tilted up all the way. Next, from the back seat get down in there under the seat and reach your hands up in the bottom seat cushion hole where the two red wires are, you will feel a round plastic disc. Turn it sideways and work it out of the hole, it is not held in by anything so it comes right out with a little working of the foam. Once you get it out of the seat the you can take the old connector off of the wire that is broke (red/white wire was broke on mine). Either you can put a new connector on your wire or just reconnect the wire together based on where it broke. There should be enough slack in the wires to fix it without taking the seat out. When your done then just work the thermostat back up into the seat bottom where you took it out. When I did this on my car, both driver and passenger side had the broken red/white wire off right at the connector on the thermostat, so I couldn't see where it was broke until I pulled out the thermostat. Once I put new connectors on both seats heaters worked great and have been ever since. Hope that helps.

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 14 Nov 2006, 17:49

Good Stuff. That will save me some time. Always important when you have kids.

Cheers

Svenska 850 Wagon · Post by **Svenska 850 Wagon** » 14 Nov 2006, 21:45

Well 50% Success. The Passenger side is back up and working. I fixed the wires on the drivers side and no go. Faulty thermostat? Loose Wire in the seat? This car did spend the last 10 years in Banff Alberta in the Rockies so the seat heater was used 6 months of the year.

Jerbob · Post by **Jerbob** » 20 Dec 2006, 15:51

Just got the word that the driver-side seat heater thermostat is bad on my 850 wagon. Cost to repair would be $72.50, parts and labor. So I'd be interested to know if anyone else got theirs to work by tilting the seat and pulling out the disk? I could by one Michellin tire instead of paying for that repair

If you don't mind, please send your reply to me at [email protected] so I know I got a response. Thanks, much.

Post by **MadeInJapan** » 20 Dec 2006, 20:06

Jerbob...find a pick-and-pull and see if there are any 850's there with heated seats. You might get lucky to find one that works. The guys at the yard are bound to not know what it is, so you might just say, "Hey, I found this...how much?" If it's a no-go on a car grave yard, then contact www.erievovo.com (call them...they typically don't answer their email) and see how much for a good used one. Good luck!

Edit: Just read in VADIS that the 1988 and later 700 and 900 series Volvo also use the same thermostat although their operating temperatures are less (37C/98.6F cut-off) than the 850 (45C/113F cut-off). So if you don't mind a bit less heat the thermostats out of these will also work. Here are part numbers:
3521779-3 came in 1988 and newer 700 and 900 series Volvo's.
1395937-4 came in 850's and early 70 series Volvo's.

Oh, another note...there was a recall on these (driver's side due to over weight people)...they were getting too hot and were a fire hazard. See if your VIN had this replaced. If not, it might be for free. Just ask the dealer about the recall.

Baker · Post by **Baker** » 20 Dec 2006, 22:39

I believe you were trying to determine the proper wire polaritys of colored coded wires.

Why not down load the "Made in Japan" 95 service manual and look at the 58 wiring diagrams. (ELECTRICAL DIAGRAMS) The color code may or may not be there. If you need help locating the diagram I can help you.