Comments: 164 Seat Heaters

[Sabo Rajko <Rajko.Sabo@domain.elided>]

When I was not satisfied with the operating temperature of the seat heating
system two years ago, I was obstinate enough to trace the problem to the
core and even get a seat stripped to heating wires.

1.	I suggest that one checks the electrical circuit up to and including
the switch (behind the switch you put a tester and observe if the bulb in it
turns on and off according to seat heater switch position (on, off).
2.	after this works correctly you have to open the seat to gain access
to temperature thermostat located somewhere at the back side of the bottom
part of the seat and check it out (now in the winter it is the right season
for doing this as you need low temperature in or outside the garage (0 to
20.C (68.F)) to cool down the thermostat enough to make it conduct through).
Ideally the thermostat should operate so as to preserve the seat temperature
at some degrees above the body temperature (around 40.C or 95.-105.F).
Higher temperatures make the seat too hot and thus uncomfortable for a
longer period.
3.	According to my experience heating elements (multiple-S curved hard
wires ) are thick and robust enough not to fail. They are designed to
sustain an effort of carrying heavy passengers. It is not likely that they
would be broken, however, bad mistreatment can damage them too (e.g. by
pressing the bottom with a knee really very hard. You can check those
elements (one in the bottom and the other one in the back part of the seat)
by by-passing (bridging over) the thermostat or even the switch. You simply
connect the heater to some spare accumulator or another 12 V source for a
minute or less.
4.	After 1, 2 and 3 are checked, the next most important issue is the
position of the thermostat. If it happened to slide near or on heating wires
after hundreds of seat-downs, the seat will remain cold even if 1, 2 and 3
all work OK - in separate tests.

The details were transferred from Alfa Digest posts to Alfa Romeo 164 FAQ:
see the group 40: Electrical, Seat Heaters in
/alfa/FAQ/164/notes0.htm
</alfa/FAQ/164/notes0.htm>  .

Rajko Sabo, Slovenia
'90 164 QV Zender
'81 Renault 18 TL
Web: http://come.to/rajko.sabo.si <http://www.come.to/rajko.sabo.si> 
e-mail: rajko.sabo@domain.elided <mailto:rajko.sabo@domain.elided> 

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