Adding Front And Rear Seat Heaters

[Squiggle Dog]

The front seat wiring harness arrived today. YEE-HAW!

It looks like the two brown ground wires (one plain, one striped) were cut at the ends so I will need to crimp some connectors on (I will probably use OEM connectors from a scrap harness so it looks like it hasn't been messed with).

The main power wire has an intact connector at the end where it attaches to a small fuse box under the hood. From there a short wire splices into what appears to be the wire that powers the radio (red with a stripe and a fuse on it), so I am assuming that at the factory they ran the power to the heated seats from the radio power wire, with a small fuse box in between.

Looking at the wiring harness it appears that there is no relay module, unlike the W126 and later sedans.

I should now have everything I need to install heated seats. I'm putting W126 heat pads in the seats right now and hopefully they will work until I can afford to rebuild/replace/reskin all seats and install new pads (and splice in the factory connectors on the them so they plug into the factory wire harness).

Sometime in the not-so-distant future I am going to remove the cracked dashboard and start removing all of the ACCII climate control components so I can start converting the system to a manual heat system that came from a Euro W116. At this time I'll be able to install the seat heater wire harnesses.

When it comes time to put it all back together I have a near mint condition brown dashboard with excellent wood from another 1980 300SD that I will install. Unfortunately, the replacement dashboard has the ACCII "sniffer" which will not be necessary, no slot for the middle vent slider, and no hole for the idle knob. I imagine a slot for the middle vent slider could be carefully cut and then the trim be inserted. Cutting a hole for an idle knob would be much more difficult.

[AMG69]

Hi Gents!!

Yes, I bought the seat heaters for WGB's 6.9 off Ebay.  I have to say in partly restoring what is now WGB's car this was one of the most satisfying "upgrades" I managed to achieve - and a big part of it was due to Major Tom's help.  I bought the after market generic new seat heater kit off EBAY from the USA.  I then spent probably six months trawling EBAY and miraculously one day found black interior matching second hand W116 B pillars with the seat heater switches in a "pick n pull" (?!) in Florida USA. I paid $250 for those Bill!!  Anyway, with MT's brilliance we fitted all four brand new seat heater pads and oEM switches which MT soldered on (replacing the modern ones).  given the rear seat was already the very rare electric reclining one (only one in Australia I believe) the heaters set it all off!  I had a guy in Wembley WA (near the Herdsman)  fit the new front switches in the burl wood surrounding the gear lever. He did a great job!

Why did I sell that car again?

Oh yeah, kids.....sigh....

[Squiggle Dog]

Hello, AMG69! I had a 1977 450SE with one heated seat and a 1979 300SD with 4 heated seats and I thought that it was a common option until I started looking around. So far I have not seen heated seats in any other W116 I've looked at except for a very few 6.9s!

I am also not sure if I want to cut holes in the zebrano wood to insert the switches, but I have a few ideas.

One idea is to use a black vinyl SLS switch housing that I have (attaches on console) and install the seat heater switches in it. I would paint the vinyl in bamboo to match the interior. So, in a sense it would be a pod like the rear seats have and would match.

Or, I could get a deleted-option switch plate for above the heater controls and cut a hole in each end to place the seat heater switches there.

[bgiovan]

I still have that console wood from the Euro 280SE 

[bgiovan]

Might be able to work something out with the radio knob area?  Not in the best of shape but I redid the one on the 126 myself and it came out pretty damn nice if I don't say so.  Here's the one I have (think I sent you a picture before...) Link

ps..still have all the other bits  

[Squiggle Dog]

Might be able to work something out with the radio knob area?  Not in the best of shape but I redid the one on the 126 myself and it came out pretty damn nice if I don't say so.  Here's the one I have (think I sent you a picture before...) Link

ps..still have all the other bits  

I was lucky to get a really nice console piece from eBay Deutschland. I can see from the backside of yours the holes where the seat heater switches would have been punched out. Mine only has one hole in the plastic backing, where yours has two. Mine is from 1978, though. I am wondering if a second square punch-out exists in the wood in mine behind the plastic backing.

I think I still want your manual window regulators with cranks since mine (at least on the driver side) are sloppy and worn out. I think those tan velour seats are great too (I even have a spare set of tan velour headrests if I wanted to add rear headrests) but I think shipping to Washington state would be a killer (for what it would cost to buy them and then have them shipped I could probably almost buy new seat skins).

[Squiggle Dog]

I think I have a solution for installing the front seat heater switches without putting holes in the console wood. I think the switch housing above the heater control area would be a good place for them.

My car has 4 switches in this area; dome light, power antenna, rear window defroster, and sunroof. My CD player has a built-in antenna switch so I won't need the factory switch anymore. I am going to convert the sunroof to manual, so I won't need that switch, either.

I want to get a switch housing piece with only the two center switch holes punched out, one for the dome light switch and one for the rear window defroster. Then I would place a seat heater switch on each end where the other switches would go (the holes would be cut only large enough for the seat heater switches). Apparently the switch housings can be bought new for $40. I wonder if they have any of the switch blanks punched out. It would be worth the money if they don't.

[Papalangi]

Are the seat switches factory?  Do they have more than one position?

The reason I ask is if they are only on/off and not factory (meaning you'd be willing to use a different style), you could try to find some unmarked rockers the same size as the others in that panel and I can laser a seat graphic onto them for you.

Plain on/off will be the easiest to find but I have found on-off-on switches at digikey.com

These could be painted black and the logo lasered into them which will make it light up.  It's not something I've tried yet but don't see it being a problem as long as we have one to burn.
http://www.aerocraftparts.com/Categories.aspx?Category=38940ec0-b260-4e9f-a23c-b80ff8e89c67

Michael

[Squiggle Dog]

These are factory W116 seat switches and they have a high and low heat position. I removed them from a 1979 300SD that had front and rear heated seats. I have the B pillars with pods and switches installed already.

The front switches mount in the center console wood, however the wood piece from that car has power window switches and my car now has manual windows. I bought a nice wooden console piece without window switches but it doesn't have holes for seat heater switches, either. In not wanting to put holes in the console wood I have tried to think of other places to mount them. I think putting the switches above the heater controls is the best idea (as my Gimp photo edit illustrates). I have the wire harnesses which the switches plug into.

Those aftermarket switches would work okay if I didn't have the original switches. The newer switches from a W126 would fit in the switch punch-outs above the heater controls but they would be sideways instead of vertical. I want the seat switches up front to match the switches in back. If I can find a switch housing with only the two center switch holes punched out or one without any holes punched out, then this idea should work out great.

[Papalangi]

I'm with you on keeping everything matching.

You can buy textured ABS and may be able to recover a four hole panel while still retaining the chrome strips but a new unpunched would be best.

Michael

[WGB]

The orange swirches are 116 originals and are switched off in the central position. If the swtch is pushed towards the single dot position  low heat is supplied to the particular seat to which it is connected.

If switched to the "2 dots" or high position the switch is illuminated and the seat heats up quite quickly.

I see there is a single seat heater switch on US e-bay at present and the buy it now price is US$170.

The following picture shows the front seat heater switches as AMG69 had them fitted to the console of my (our) car.



and in the position they are fitted in the AMG car in the museum in Stuttgart.



The 116 sales brochure shows them mounted in the console at the forward edge either side of the gear selector.



One thing that this shows is that my switches are mounted upside down - the high seat heat should be a forward press and the low heat setting should be a rearward press according to these photos.

The rear seat heater switches are as AMG69 says mounted in pods attached to the lower end of the B-pillar trim and the left side one is just visible in the centre of the right hand border of this next picture.



Bill

[Squiggle Dog]

Good pictures. It's interesting seeing all of the different variations of switch positioning in the console. The console wood the seat switches came from had them mounted forward on each side as in the brochure. If you look at previous posts in this thread you can see my B pillars which have the switches for the rear seats mounted in the pods.

[Casey]

The 116 sales brochure shows them mounted in the console at the forward edge either side of the gear selector.

I rather prefer this positioning as Squiggle Dog ended up getting in his car.  The only thing I'd like different is to have a zebrano  wood panel from an older W116 that has the raised dial fader rather than the recessed one shown here, such as this:



I think it pretty unlikely to find a combination of both the dial fader switch style WITH heated seat switches, but I'd be happy just finding one without the fader cutout on the side - I'm comfortable taking care with drilling the zebrano myself.  So please let me know if anybody knows where to find a zebrano version of the vinyl center piece pictured above.  Likewise I am also looking for all the other heated seat components!

[Squiggle Dog]

I have a zebrano wood piece with the holes for the heated seat switches plus the holes for the power window switches, but it has the newer fader style. I believe I also have a vinyl center console piece with the round fader knob and it had the heated seat switches, but it's vinyl...

In either case, I don't believe either style fader switch can be used with a modern sound system because they can't handle the power going through them. But as far as looks go, I imagine a round knob looks better than the newer style and could probably be altered to work correctly with a modern head unit. I was fortunate enough to find a brand new center console piece without any hole for a fader.

[Casey]

I have a zebrano wood piece with the holes for the heated seat switches plus the holes for the power window switches, but it has the newer fader style.

I might end up wanting to buy that off you if I can't find anything else - but I'd rather have one without any fader switch than the newer style.  I figure I'll either go with a Becker Mexico that supports the fader dial, or a modern head unit that uses neither.  The idea of getting a Becker installed is growing on me though.  I thought the issue with newer head units is that they have digital fader controls, not analog?