grohgreg

Relays have a failure rate, just like any other component. Could be bad spring, could be bad contact, could be bad anything. From the perspective of "time is money", your troubleshooting has essentially taken you to the lowest practical level for the moment. Replace the suspect part. If the issue persists, THEN invest in additional troubleshooting.

//greg//

ArneeA

this

Brit6

I have an update on this, it worked for 2 weeks without hassle. Went to turn on my seat yesterday and no heat, checked the fuse again and it has blown. Put in another 5amp and the seats work again, but who knows for how long.
I have ordered a new relay for $8 from usa.

fast996

OP, where was that relay under the dash for the heated seats? easy to get to? thanks

dcflyer

I'm interested in where that relay would be too...I have a similar problem with my driver's seat.

Brit6

Argh......I installed the new relay under the dash and it worked for maybe 2-3 weeks max. It keeps blowing the 5amp still, not always on start up, but I didn't even get a day from the fuse i put in yesterday.

The next idea I have is the control unit under the drivers seat. It's about ~$60. The rear seats won't work with any of the fuses being blown so they must be all connected.

Guy's PM your e-mail addresses and i will send you the documents

Brit6

I also thought that it possibly could be a main battery issue.

XR4Tim

I would suspect the control unit next. There is one under each of the front seats if I remember right. I have the Porsche seat heating test plan. I'll look at it tomorrow and see if I'm forgetting anything.

chasz

Speaking generally, when heated seats fail it is usually the heater mat in the seat that has a short or break in the element. It could be that yours is simply an intermittent short in the mat.

Dennis C

In my case the passenger's side seat heater no longer heats the seat, and the seatbelt warning chime for that seat no longer works. The fuses look good.

Slow Guy

Well Dennis, I do like my heated seats but could do without the seatbelt chime, if you figure out how to get the one w/out the other please let me know.

Dennis C

I'd take the seatbelt chime over the "wife chime" telling me about how the heated seat doesn't work...

Slow Guy

Well you could let her drive and you ride bitch.

Just sayin'

Brit6

I am still troubleshooting this annoying issue.

I replaced the main battery about 2 weeks ago, I turned the front seats on and they worked for about a day then the fuse blew again.

I noticed in the Porsche seat heating test plan this:

Seat heating relay
8 Switch on ignition and check voltage at pin
1 of seat heating relay (in relay carrier at
left of dashboard, slot 8).
> 11V
→ Step 9
Check lead and plug connection
from fuse F39 in fuse carrier at left
to seat heating relay, slot 1.
9 Switch on ignition and check voltage at pin
5 of seat heating relay (in relay carrier at
left of dashboard, slot 8).
> 11V
→ Step 10
→ Step 11
10 Switch off ignition and check voltage at pin
3 of seat heating relay (in relay carrier at
left of dashboard, slot 8).
> 11V
→ Step 11
Check lead from pin 3 of seat
heating relay to fuse F22.
11 Switch on ignition and check voltage at pin
2 of seat heating relay (in relay carrier at
left of dashboard, slot 8).
< Replace 0.3 V relay
for seat heating.
→ End
>0.3V → Step 12
Check lead and plug connection
from pin 2 of seat heating relay to
pin 75 of Kessy control unit.
12 Check Kessy control unit function, seat
heating part.
→ 966619 Removing and installing
Kessy/immobilizer control unit
→ End

This is interesting as i just replaced the 2 mosfets and the 6 resistors on my KESSY module so that fixed my Entry And Drive issue.

I wonder if that would have fixed my heated seat problem?

Only thing left would be Seating heating switches, Seat heating control unit, or a faulty mat.

Brit6

Just tried it when I got home, put in a fuse in #34 and it blew when I turned on the passenger seat.

Running out of patience, this might be a dealer fix.