Thread: P38 heated seats

Hmm, that is very interesting. Now it is time for RAVE research to understand how to replicate the switches and test to see if the BeCM has any input to the process and if the Australian programming of BeCMs disables the elements in a different way.

Are the HEVAC switches a mechanical toggle switch like the hazard lights or a momentary switch like the air distribution switches?

Does the heated seat switch retain its setting after removing the key?

Originally Posted by glenhendry

Hmm, that is very interesting. Now it is time for RAVE research to understand how to replicate the switches and test to see if the BeCM has any input to the process and if the Australian programming of BeCMs disables the elements in a different way.

Are the HEVAC switches a mechanical toggle switch like the hazard lights or a momentary switch like the air distribution switches?

Does the heated seat switch retain its setting after removing the key?

When i turn the seat heaters on with the Faultmate, the relays sound like they are coming from the BECM.

Rave seems to be telling me that I need to earth wire 6 from Connector 1279 to turn on the drivers seat and earth wire 15 from the same connector for the passenger seat. After that it looks like the BeCM does the rest.

I will try this weekend. Anyone who wants to warn me of blowing stuff up, please do. Anyone who wants to confirm my wiring diagram readings, please do

Originally Posted by glenhendry

Are the HEVAC switches a mechanical toggle switch like the hazard lights or a momentary switch like the air distribution switches?

Here's a pic of mine - seat heater switches are bottom right and bottom left. Right seat is on, it's a momentary switch that makes the light on the switch light up and a solenoid under the seat clicks on.

Serves you right for owning a P38 rather than a PROPER RR.

My 1994 Classic RR (Vogue LSE) had seat warmers AND they worked.

Originally Posted by VladTepes

Serves you right for owning a P38 rather than a PROPER RR. My 1994 Classic RR (Vogue LSE) had seat warmers AND they worked.

I'll ignore that, on this P38 forum .

There is a problem, fuse 2 is missing from the BeCM, that means I may be missing more than just the switch on the HEVAC head unit. All the wiring cant be difficult to put back in though, if I am keen enough.

Originally Posted by glenhendry

I'll ignore that, on this P38 forum .

There is a problem, fuse 2 is missing from the BeCM, that means I may be missing more than just the switch on the HEVAC head unit. All the wiring cant be difficult to put back in though, if I am keen enough.

keep us informed!

I have just installed a HEVAC from UK with the heated seat buttons. The lights on the buttons work as expected, and I hear a click behind the dash. I also confirm that there is 13v going through the becm and into the connector under the seat. Since I get no heat, I assume that the seat element is broken. The summary is though, for HSEs at least, you can just plug in the HEVAC controller and you should be good.