Heated Seats Got Me Baffled !!

singring

New Member
Messages
18
Likes
0
Location
Saskatoon SK Canada
#1
Since I bought my 1995 318i last year, only the backs of the front seats will heat up, with no temperature change on the seat bottoms. So, today, I checked for voltage at the connectors to the heat elements...all connectors say 12 volts. OK, then I checked for continuity from the heat elements themselves...now, I would expect to see that the circuit is closed for the heat elements for the seat backs( which work fine), and that the circuit is open for the heat elements for the seat bottoms( which don't work)....however, the ohmmeter reading for ALL elements is exactly the same, 6.3 ,so I checked the ohmmeter....probes apart, reading is 0.0...
probes together, reading constantly fluctuating....
What I don't understand, is that the continuity of the elements that work, and those that do not work, is the same, and since voltage is being fed to the elements connectors, then ALL the heat elements should be working.
Or, is there a fuse, or a fuse link, hidden somewhere, that may be blown and is not allowing the voltage to get to the seat bottom elements.
Everything else is working fine electrically, and mechanically, on this car, and I have checked the appropriate fuses, but all seem to be OK.
Any ideas ????
Thanks
 
Messages
4,917
Likes
18
Location
Reading,PA
#2
The probable explanation is that the heater elements are wired in parallel. That means that only ONE has to be good for your meter to read continuity, the rest can be open circuit (failed). It is very common for the seat back to work and the seat bottom to fail, due to the constant flexing from your weight on the seat bottom. The seat back does not get the stress of 100 - 200+ lbs. on it.

I am pretty sure that BAVAuto.com has a replacement kit.
 


Top