Need advice please

[Mazza]

I am going to retrofit heated seats in my 1998 Z3 as need to appease the wife. She likes the car but complains that the leather seats are cold!
Thanks to SFIAC, I have the two heated seat switches on their way, but I am not sure about what heat pads to buy. There seems to be loads, and fairly cheap, but not sure of the quality of offshore products. Is there anywhere in the UK I can get them? Or anyone that can recommend any.
I am aiming to strip down the seats and install the heat pads under the leather covers. ( and get a small leather repair done while I’m at it)
Also if anyone has done this before some info on the wiring would be useful.

Any help gratefully received

 

[t-tony]

@Antm72

Tony.

 

[andyglym]

@mrscalex has just about completed a 100% refurb for me, including heated pads.

 

[Antm72]

I retro fitted the heat pads in to mine and have had them in pushing 2 years now with out issue. The kits with the honeycomb mesh are on the cheap side but i have not had any issues at all fitting them.
The seats already had the wiring as they where heated but they had failed as the BMW design is not the best and the honeycomb system allows the pads to be cut and shaped.
The retro fit kit comes with complete loom i believe that @Dino D has just fitted the complete kit to his car.

 

[hard top]

@Mazza have a read of this thread ....

https://zroadster.org/threads/heating-standard-seats.20980/#post-354927

 

[Dino D]

I retro fitted the heat pads in to mine and have had them in pushing 2 years now with out issue. The kits with the honeycomb mesh are on the cheap side but i have not had any issues at all fitting them.
The seats already had the wiring as they where heated but they had failed as the BMW design is not the best and the honeycomb system allows the pads to be cut and shaped.
The retro fit kit comes with complete loom i believe that @Dino D has just fitted the complete kit to his car.

Yep I’ve done that on my Sparcos and used the OEM switches.
The systems is much better than OEM because if a strand breaks it doesn’t stop working or cause a hot spot. The OEM also gets rusty when you door seals inevitably leak..
They are from China but the wiring seems a decent gauge, but thicker than the original I think.

Will be fitting a set into the family bus next.

The wiring was actually simple as it just 2 wires - live and nuetral. I think I made a post about it last year when doing it.

 

[Dino D]

This will help with the wiring, it’s actually simple but I looked at all the switch wiring that comes with the kit at first, it’s reduntant as you will use the OEM switches and the Cars wiring that is already there.
https://zroadster.org/threads/heated-seat-wiring-help-aftermarket-kit.19309/#post-324094

 

[Mazza]

Dino D,
just looked at the link from Hardtop, and found an eBay link.
They look ok and at about £55 they have got to be better than the £8-10 ones that I had previously found online.

Thanks for the wiring pictures........

Soon to be a happy HOT BOT !

 

[Mazza]

Just been out looking for the black 4 way Connector under the seats with no luck. Must be buried in the carpet somewhere. On the circuit diagram it is connector X733. I did see a picture of this connector and it is an AMP part. The Amp number is stamped on it so if anyone can tell me the number Starts 1-xxxxxxxx-1. I was an electronics buyer before I retired so I should be able to locate the mating half and correct crimps once I have this part number. I can then make the proper connection for the heated seats.
Also, just found out that the passenger seat. Goes up/ down but not forwards and backwards. Possibly motor duff.
BMW ref 67318398810. If any one has a spare send me a message as could well be in the market for one.

Just one thing, to get the seat out, it states move seat back undo front bolts, move seat forward and take out rear bolts.......if it doesn’t move how can you get the bolts out???

 

[t-tony]

Just as a possibility, have you tried giving the motors, on both seats, a gentle smack with a small hammer?

Tony.

 

[Mazza]

Drivers side works fine, it’s just passenger side that doesn’t go forwards and backwards. I have hammers from small pein, to 16lb sledge......but would a rubber mallet be better?

 

[t-tony]

Drivers side works fine, it’s just passenger side that doesn’t go forwards and backwards. I have hammers from small pein, to 16lb sledge......but would a rubber mallet be better?

Usually a sharp metallic contact is better.

Tony

 

[Layor]

Mmmm... something like a whacker plate then, Tony
Colin.

 

[Mazza]

Just put a meter on the connections under the seats. All ok other than there is no continuity through the passenger side forward/ backward motor, so need to get it out to either fix or replace.
But How ?
Seat won’t move so how do you undo the 4 bolts that hold the seat in place. It may be possible to get to the front ones albeit bloody difficult, but I can’t even see the rear ones.

 

[Mazza]

Found out a way of moving the seat.
Raise the seat up ( this motor works!) and you can see the horizontal motor at the front of the seat. If you release the two screws, there is enough movement as drive shafts from the motor are sprung loaded, to be able to remove the shafts. Then insert the shafts back into the seat rail drives and turn them by hand to enable the seat to move. One side goes clockwise the other goes anti-clockwise. (Find out which way when I do it)
Apparently it takes ages but at least you can expose the nuts to be able to remove the seat.

You may need someone to wiggle the seat while you turn the shafts to make it easier, and you can, room permitting, attach a battery drill that has forward and reverse to the shaft and turn it that way. But only about half an inch at a time on each side so you don’t jamb it up.

I’ll update tomorrow and advise if this actually works!!!!

 

[Mazza]

As you can see it worked and took about 20 minutes to get the seat out.

I took out all 4 Torx screws to release the motor (actually 3 as 1 was missing), the found there is a lot a movement in the shafts so it came off quite easily. Then pulled out the shafts from the motor. I used the smaller one in my battery drill and alternated between the drive boxes to move the seat bit by bit forward and backwards and exposed the fixings.
Once they we out took the negative terminal off the battery, removed the seat belt , and then removed all the electrical connections under the seat. Then just lifted it out ( with the roof down!)

I found the heated seat connector which is an AMP 1-828819-1. Unfortunately on the Tyco website this number comes up as a restricted product. Which probably means BMW have blocked sales of this and the mating half.
That’s a shame as it would have been good to use the correct connectors when I fit the heat pads.

Motor definitely duff......no continuity through the coil.

 

[t-tony]

Just in case you didn't know, when you reconnect the battery don't turn ignition on until the seats are fully reconnected or you may cause the Airdag light to come on. Best to leave the key out of the ignition altogether.

Tony

 

[Mazza]

Just for info, the I took a couple of pics of the cables under the seat. The black connector is for the heated seats.

Good news .....I found £1.20 .............Bad news......the £1.00 is no longer legal tender

Need to get the hoover out now........wonder where the wife keeps it?

 

[Mazza]

Just in case you didn't know, when you reconnect the battery don't turn ignition on until the seats are fully reconnected or you may cause the Airdag light to come on. Best to leave the key out of the ignition altogether.

Tony

Thanks for that. I think you have saved me a lot of hassle!!

When I disconnected the battery there was a noise from an alarm system in the engine bay (on the passenger side under the fuse box. Not loud and only lasted about 30-45 seconds then stopped. I didn’t think the alarm worked anyway so was a bit surprised to hear it.

 

[Mazza]

Just in case you didn't know, when you reconnect the battery don't turn ignition on until the seats are fully reconnected or you may cause the Airdag light to come on. Best to leave the key out of the ignition altogether.

Tony

While I already have one of the seats out, I thought, while I am sorting out finding a replacement motor, I may as well remove the drivers seat and the centre console to find the red connectors for the heated seats switches, and strip the seats down to install the heat pads.
Is it ok just to reconnect the battery neg terminal so I can move the drivers seat back and forward to get to the fixings, then disconnect again before undoing the seat connections.