Heated seats broke but not usual problem?

Hi, Can anyone help please?

Car is a 1998 P38 DSE with heated seats not working.

I've tested the elements with a mutimeter and get a reading from both parts on the passenger seat but only the seat back on my (driver) seat meaning all should work apart from driver seat base.

I've tried the paperclip fix to bypass the seat squab element and so just heat the back part but still no heat on both seats.

Fuses are all ok.

The light comes on to say seats should be working with engine running so this part also seems ok.

Any relays or more fuses etc. that anyone is aware of that could have failed?

Also, how can I test if power is coming to the seat connectors coming out of carpet underneath each seat when the switch is turned on? Is this worth trying?

Thanks
John.

Just stick a multi-meter between the pins of the connector to the seat, that should give you 12V it's working correctly.

What readings are you getting when you test the elements?

Hi, thanks for the reply.

I'm really crap on electrics and multimeters but here's what I've tried but it may be wrong...

I started the engine and switched the heated seats on. With the connectors unplugges I went to the parts that comes up out of the carpet as I think these are the feeds. I tested both (there are only two pins in each) with my multimeter set to DCV 20. Nothing registered on either connector.

I tested the connectors that drop down from the seat and changed the multimeter to OHM 20K. On this setting the MM shows 1 . on the display. When I connected to the big connector for the seat base nothing changed (I think this means the element is broken somewhere?) When I teste the smaller connector for the backrest part of the seat the rreading changed and showed all zero's - does this mean the circuit is intact as that also happens if I touch the MM probes together?

Maybe I'm just doing it all wrong - if not does it mean I've got no power to the heated elements?

Thanks again for the help.
John.

Well, you haven't electrocuted yourself or burnt your car to the ground so you can't be that bad at electrics.

No volts at the feed means there is a problem with the fuses or relays, so check them both over. Do you have the ETM from RAVE?

Try a lower range for the resistance reading, the element will have a resistance of ~1 Ohm if it is ok. Your multimeter must show infinite resistance, an open circuit, as 1, and this will be your broken element. It shouldn't show all zeros as this would blow the fuse, so make sure it isn't shorted anywhere.

I might try the same later with my seats, blinking things have never worked either...

Right, actually did check my seats last night, and got the same results as you did, the seat base had an open circuit, and the seat back read 10 Ohms, however when switched I received 12V at the supply connector.

Looking at the circuit diagram, the switch will light up even if the supply fuse or relay is defective, as the switch is an input into the BECM.

Check your supply fuse and relay, but odds are you also have an open circuit in the seat base, which is pain in the ass to fix but is possible.