Heated seat pad

[rajinder_1]

Hi Guys,
just a quickie, can any heater pad be used to replace a faulty one in a SL320 or do you need to have the correct one, thinking of cost, its cheaper to buy certain pads for certain cars.....
its just 2 wires i believe that will need to be connected...

Raj

 

[television]

Hi Guys,
just a quickie, can any heater pad be used to replace a faulty one in a SL320 or do you need to have the correct one, thinking of cost, its cheaper to buy certain pads for certain cars.....
its just 2 wires i believe that will need to be connected...

Raj

No reason why any heater pad could not be used, are not there 3 wires

 

[BlackC55]

I think it comes with the leather......

 

[rajinder_1]

No reason why any heater pad could not be used, are not there 3 wires

Oooops maybe, i was hazzarding a guess thanks malcolm

Raj

 

[rajinder_1]

I think it comes with the leather......

yes i thought that but i dont want to replace the whole cover just for the pad.
i have read on here that you can remove the cover and put a pad under it, it supposedly does work proably not as effective as the one in the leather but then at least my tooch is warm....

Raj

 

[television]

Oooops maybe, i was hazzarding a guess thanks malcolm

Raj

Yes they are as Black say and stitched, the reason why there is more than two wires is the they have 2 settings, but you could use any pad as long as it fits

 

[richard]

Yes they are as Black say and stitched, the reason why there is more than two wires is the they have 2 settings, but you could use any pad as long as it fits

Malcolm. There are 2 wires to each pad - On the 129 SL, one side of the base pad is grounded, and the positive is commoned with the one lead to the backrest pad, and that common positive and the other lead from the backrest go back to the control unit. So the control unit is doing something clever with the backrest pad (more than whatever its doing with the base pad).

Certainly on the newer cars the control unit cycles the power to the seat pads to do the different heat settings. Full on applies power all the time. From memory the cycle has a frequency of about 25Hz with about 30% on for the 2 stage heated seats. No idea about the 3 stage variety in ML/E etc

What is particularly clever is on the W203/W209/A/B the control unit, when on low setting, alternates the power between the two seats to keep the peak current demand lower. I dont think this happens on the SL (R230) where there is a control unit per seat and the heated seat switches are not in the same control panel.

Cheers
Richard

 

[Alfie]

No reason why any heater pad could not be used, are not there 3 wires

There are different heating pads for different cars/trim levels. For example the heated seat pads for an A/B class with leather are different to those for a car with cloth.

Care needs to be taken here as the seat pads draw a significant amount of current and getting things wrong can cause serious problems (fire). Mine are protected by a 25 amp fuse which is the standard for an A class.

Be careful not to use seat pads that draw too much current for the wiring for that car otherwise its not just the seats that will get warm

 

[television]

Thank you Alfie and Richard, pulsing would certainly cut down on the wiring to these things, being fused at some 25amp does show that some serious current is flowing ( there has to be) even if running at 15amp that is quite a load on the cables.
Thank you again

 

[rajinder_1]

i was looking at a seat pad from a ML for my SL but it seems like this will not work then???

 

[television]

i was looking at a seat pad from a ML for my SL but it seems like this will not work then???

Well I will stick my neck out and say why not as they all operate on the same principle.