Login Register

Thermostat replacement on heated seats.

Help, Advice and DIY Tutorials on Volvo's P80 platform cars -- Volvo's 1990s "bread and butter" cars -- powered by the ubiquitous and durable Volvo inline 5-cylinder engine.

1992 - 1997 850, including 850 R, 850 T-5R, 850 T-5, 850 GLT
1997 - 2000 S70, S70 AWD
1997 - 2000 V70, V70 AWD
1997 - 2000 V70-XC
1997 - 2004 C70

This topic is in the MVS Volvo Repair Database » Volvo: House calls with App based Pick up and Delivery service
Post Reply
tailor
Posts: 570
Joined: 12 November 2006
Year and Model: 2004 XC90 2.5T AWD
Location: Toronto
Been thanked: 2 times

Volvo Repair Database Thermostat replacement on heated seats.

Post by tailor »

Heated seat thermostat replacement.

Firstly let me start by apologizing as I have been searching for posts about fixing the heated seats, for some reason I cannot find them, if necessary (The Mods) may move this post to the correct spot or as an add on to seats in general.

I am going to assume that every precaution and a good dose of common sense will be employed when tackling this and any other repairs.( There are no stupid questions , only stupid answers.)
As I stated in my post about swapping seats, 97 into 94, some months ago I needed to get the bum warmer going, for enthralling reading see post: https://www.matthewsvolvosite.com/forums ... hp?p=52203
Seems as if my pics have gone missing! Matt!!!!
Also worth a visit and read is Ozarks foam replacement
https://www.matthewsvolvosite.com/forums ... hp?p=30367

Why I chose a day of -12c to do it I am not certain :roll: .

I proceeded to do the back probing, to check if there was continuity or power under the seat.
I made use of this post here by Ozark Lee: http://volvospeed.com/vs_forum/index.ph ... try1245971
Everything was good until I tried to check the thermostat, a quick peek below the seat showed me that the wires where in fact disconnected. Not so quick slim!
I found that the seat had been worked on before and a lousy job had been done of it. The connector came off in my hands and the pin on the thermostat had been broken off, the problem was solved.....in theory at least!
The offending item!
Image
The piece of the pin in the connector
Image
This is what the connectors looked like.
Image
This what they should look like.
Image
With the seat removed I tackled the removal of the metal rings on the sides and the front of the seat cushion, I did try save as many rings as possible.
I also removed some the metal rings from the right top side of the seat cushion to allow the leather to be peeled back a little further to give me access to the thermostat. The thermostat just " drops in."
Image
Image
Above shows the thermostat hole from the top side of the seat.

A quick re-crimp of the wire and insertion of another thermostat, I happened to get a few from the yard on my last visit, lucky for me. :mrgreen:
I pushed in the connectors, but did not do any extra tape or cable tie work, I hope that it will suffice.
Image
Image
The closing up of the seat was not too hard, I must strongly agree with a previous poster who (I think it was a post about replacing the seat foam) suggested using cable ties on the seat cushion, it is less of a fight, I used the metal rings on the outside of the seat as OEM method.

All back in and bolts tightened to spec. Toasty 8) 8)
1994 850 Auto Turbo wagon 306000km (Sold)
2004 XC90 AWD 188000km

"Life is like a reel to reel tape recorder,
the closer you get to the end,
the faster it spins."
Abe Gottschalk

Ozark Lee
MVS Moderator
Posts: 14798
Joined: 7 September 2006
Year and Model: Many Volvos
Location: USA Midwest
Has thanked: 4 times
Been thanked: 75 times

Post by Ozark Lee »

Well done Tailor, pinned to the repair database. I guess -12° C isn't so bad with working seat heaters.

...Lee
'94 850 N/A 5 speed
'96 Platinum Edition Turbo
Previous:
1999 V70XC - Nautic Blue - Totaled while parked.
1999 V70XC - RIP - Wrecked Parts Car.
1998 S70 T5
1996 850 N/A
1989 740 GLT
1986 740 GLT
1972 142 Grand Luxe

User avatar
BEJinFbk
Posts: 4067
Joined: 5 January 2008
Year and Model: '98 V70 R
Location: Fairbanks, Alaska
Has thanked: 93 times
Been thanked: 146 times

Post by BEJinFbk »

Great Write-Up!
Glad to hear you got the bun warmers cooking.
It was -42 here today, and they make it a lot easier to deal with.
Gotta love those heated seats! :mrgreen:
'98 V70 R - Well Equipped for Life Up North... ;)

rezamash
Posts: 3
Joined: 20 January 2009
Year and Model:
Location:

Post by rezamash »

Hello,
I have a problem with my car seat. Sometimes it heats up and sometimes it doesn't work at all. Is it a thermostat issue or something else.

I have a '95 850GTL and love it to death.

Also, the back of the seat is not moving back and forth. However, I can hear the motor running. The seat itself moves up and down and back and forth. Any suggestion? I couldn't find a threat regarding this issue.

Thanks.

MadeInJapan
MVS Moderator
Posts: 13434
Joined: 31 March 2005
Year and Model: '98 S70 T5 '07S40T5
Location: Knoxville, TN American but born in Japan
Has thanked: 17 times
Been thanked: 35 times

Post by MadeInJapan »

Probably a bad/corroded connection for the heater to work some of the time. In regards to the motor working but not moving the seat, this is typically a frayed or broken wire. I believe there's a write-up on this in the repair database as well.
'98 S70 T5 Emrld Grn Met/Beige Tons of Upgrades Mobil-1
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo

rezamash
Posts: 3
Joined: 20 January 2009
Year and Model:
Location:

Post by rezamash »

thanks.

MadeInJapan
MVS Moderator
Posts: 13434
Joined: 31 March 2005
Year and Model: '98 S70 T5 '07S40T5
Location: Knoxville, TN American but born in Japan
Has thanked: 17 times
Been thanked: 35 times

Post by MadeInJapan »

Another possibility is that you have a broken wire and the movement of the seat will allow it to make contact at times and not at others- I would think it's an easy fix. Get down under the seat and check for a broken wire or one that's frayed and barely making contact. Good luck and keep us posted!
-MIJ
'98 S70 T5 Emrld Grn Met/Beige Tons of Upgrades Mobil-1
'04 V70 2.5T Red/Taupe Some Upgrades Mobil-1
'07 S40 T5 AWD 6 speed manual! Silver/Black Stage1 Heico & Elevate
'07 S60 2.5T Blue/Taupe- my kid's Volvo

rezamash
Posts: 3
Joined: 20 January 2009
Year and Model:
Location:

Post by rezamash »

I will.

Thanks again

milesursogood
Posts: 101
Joined: 26 September 2009
Year and Model: 850 T-5, 1997
Location: Portland
Been thanked: 1 time

Post by milesursogood »

tailor - where did you purchase the new seat thermostat? mine broke as well from the connector. they sure are flimsy specially if you're going to locate on a flexible cushion surface. anyway, how long did it take you to remove the seat & replace the bottom thermostat? do you have a reference instruction or link that you can post that you used to remove the seat & cushion off the car? thanks.

mdempst_79
Posts: 50
Joined: 18 October 2008
Year and Model: 2006,2007 XC90
Location: Durham / Ontario,Canada

Post by mdempst_79 »

Just an FYI on this repair, as I did mine last night.

My thermostat wires were broken, so instead of going through the pain of removing all of the clips to access the thermostat, just flip the seat over so you can get a good view of the thermostat going into the lower cushion. Then you can take your fingers and spread the hole while pulling the thermostat down (you should be able to feel the top of the plastic ring). Then it just wiggles out from below. You install the same way, but when you put it up, the thermostat should pretty much bottom out against the seating surface (you can feel that its installed, by touching the cushion and feeling it bottom out.).

Saves you a huge headache if that is your only problem.

Mark
2007 XC90 V8 Sport 265,000km
1994 850 Turbo Auto 365,000km (R.I.P - 2005-2017)
2006 Ford F350 Super Duty 4x4 Diesel
1999 Landrover Discovery II 259,000km
1992 Range Rover Classic 3.9 250,000km (In restoration)

Post Reply
  • Similar Topics
    Replies
    Views
    Last post