my rear seat heater is not working...never have since i bought car last year...any suggestions?
98 S70 GLT 135,000

Seat Heaters in the rear? Perhaps your thinking of your S Class and not your S70.

i have a heater switch in console facing rear....was told by previous owner that the rear seats are heated...rare?.....i will check on the "lumbar theory" but i'm sure this is for rear seats

If you have a switch mounted on the rear of your console, your car is at least wired for rear heated seats. The circuit is fairly simple: there is a fuse, a relay, the switch, 2 thermal/circuit breakers (one in each rear seat), and 4 heater pads (2 each cushion and backrest).
When you operate the switch, an LED in the switch should turn on (this is separate from the light that comes on with your headlights). If it does, this means the fuse, relay, and switch are all OK, and the problem lies in wiring to the seats, the breakers, or the heater pads. If the LED does not turn on, the problem lies between the battery and switch. I have a circuit diagram with wire colors and component locations if you feel capable of "troubleshooting".

my light on the console is on, so i will attempt to trace it back to the breakers or pads...i would greatly appreciate the diagram. Have you ever seen a S70 with rear heat?..Thanks

Send me an eMail message at n0v8or@cox.net and I will reply with the wiring diagram attached as a JPG image.
You should be able to check continuity of the breakers and heater pads from one of the termainals of the switch, with an ohmmeter. It seems unlikely that both seats would fail simultaneously; my guess is that someone removed the rear seat, disconnected a wire, or a connector, and did not reconnect it when replacing the seat.

No, I have never seen an S70 with the rear heated seats. My sales brochure from 1998 lists them as an available option in Canada.

I think he might be referring to the lumbar section of the front seats?