P38 electrical gremlins...

[Talkwrench]

Are there any P38 electrical experts around? My 1997 4.6 Autobiography has a few niggly faults that I'm trying to get to the bottom of. The heated windscreen and heated seats do not work. When the buttons are pressed, no indicator lights illuminate. The rear screen demist does work and the rest of the heating system functions normally.
Ive checked all fuses and relays and everything is as it should be. I've also checked and cleaned all connections at the fuse box and at the BCM.
When I short the relay contacts in the fuse box, the heated windscreen works correctly so the main live feed is fine. It is the switching circuits that are at fault.
What is the most likely cause? Fuse box, HEVAC or BCM?
The fuse box doesnt look burnt or overheated anywhere.
All ideas most welcome!

[Trooper2]

You say your not getting a confirming "on" light. Have you checked the continuity of the switches in on and off positions to make sure they are working?

You didn't mention it in your post so I thought I'd ask..

[agent006]

I'd go with a dying hevac panel. From what i remember, it's quite easy to get the front off to then give the buttons a quick bath of contact cleaner.

[Talkwrench]

Should have mentioned that I've had the HEVAC out and stripped and cleaned all the contacts. For those who've never been inside, its a rubber membrane type front panel - the sort you find on calculators and mobile phones.
No continuity problems. I tried shorting the switch contacts out but still no indicator light or correct operation.
It does seem that the HEVAC is the most likely cause.
Oh well - its take the plunge on Ebay, I guess!

[CY88]

Seats can be a problem because the heating filament breaks from wear and tear. Here's an article on DIY fixes.....

http://www.rangerovers.net/repairdetails/seats/sea...

[Talkwrench]

I'm aware of the seat element problems but I believe this is a different problem. I'm showing no indicator lights when they are switched on - and likewise for the heated screen. I'll have to take the plunge with the hevac, I guess - unless anyone else has experienced the same problem and found it to be something else?

[agent006]

Blown bulbs? Does the screen actually work?

[Talkwrench]

Ahh, If only it were that simple!
No, not just the bulbs unfortunately.
Neither the seats nor the screen are getting warm.
As I mentioned, if I short the relay contacts for the screen, it works - so the problem is definitely in the switching circuit. And no power reaching the seat elements either.