Really Odd seat heat problems

dallas90 · #1 (**permalink**) 10-26-09, 06:46 PM

All lights work, relays snap once when turned on, but no heat to any seat or seat back. All 4 fuses are good. Pulled the plug on the rear seat and checked Ohms, showed continuity for all 4 pads.
I removed the positive cable from the battery, waited an hour, replaced cable. Had RT Front seat heat but no other (not just killer hot, but I wasn't sitting on it either). Still had all lights and one relay snap per seat.
Removed positive cable again, waited an hour, now no heat at any seat. Still have all lights and one relay snap per seat.
Will seat heat throw codes? Any guesses as to where the problem is?
I installed an aftermarket tire pressure system last month. I'm taking power from the battery for memory and the IGN 1 relay for the display head. I don't see how this could be causing my problems, but I tried the seats with the power line removed from IGN 1 and even swapped the relay with the reverse light relay. No difference, no heat at all 4 seats.
The latest, and weirdest. Short drive home from the Y, put on heat on both front seats. No heat. Put drivers seat into "massage mode" hear a click. Passenger seat heat now working well. Drivers seat may have started to heat as well, but pulled into the garage. Still no heat on the rear seats.

dallas90 · #2 (**permalink**) 10-26-09, 09:25 PM

The latest is, after the massage mode was used the rear and passenger seats are heating, but not the driver seat.

**Ranger** · #3 (**permalink**) 10-26-09, 09:35 PM

That sounds like a loose wire somewhere. Have you tried the drivers massage mode?

dallas90 · #4 (**permalink**) 10-26-09, 10:27 PM

It was the drivers side that I put in massage mode, I haven't tried massage mode on the pax side. I'll try that in the morning. After that I'm thinking of checking continuity on the drivers seat heat pads.
I'm pretty sure I need to remove the wires from the smaller of the two boxes under the drivers seat (there is only one box on the pax side, it's the same as the small one on drivers side).

dallas90 · #5 (**permalink**) 10-27-09, 11:31 PM

All right, today I took the seats apart. I used the control module from the Pax seat on the drivers seat and it didn't make the seat hot. With every thing apart I could hear the relay double click. So now I'm pretty sure it's the damaged element. I have the plugs out of the module and I saw a diagnostic someone posted, but the ohm readings I got don't make sense. In other words, The labeling on the plug doesn't seem to match the letters on the diagnostics. So I'm still not sure which elements are bad. Tomorrow, if I have the time, I'll take it apart to the point of taking the leather off the seat and try to figure out from there which ones are bad.