Can anyone recommend first steps in diagnosing a heat seating problem?

Before I take it in for the $90/hr (please bend over) charger to diagnose and fix this problem, I thought I'd run it by you guys and gals (any gals out there).

Description: '99 C280 with heated sport seats
Passenger side seat heats
Toggle lights are working on drivers side (low/high)
Neither seat bottom or seat back warm on drivers side.

Questions: Is there a separate fuse for the drivers side seat and the pass seat?
If it is the heater fillament, which I suspect, is it possible to repair oneself?

 

Is it that cold up there in the PNW

There are 2 fuses #1 & #11.

The control unit requires 11v minimum to operate but since the rt side works, input voltage shouldn't be the problem.

There are 2 elements per seat - bottom cushion and backrest - resistance should be 2.5 - 3.0 ohms for each. I cannot say which connector (X55) is b/c our car is not equipped, but the connector is directly beneath the front of the seat with the rest of the wiring, look for broken or chaffed wires since these are exposed and easily damaged.

The control unit is what the switches are mounted to, remove radio to replace (about $135us).

Good luck!

 

Thanks for the reply.

Fuses 1& 11 look OK.

Do you suppose the control unit is bad if the pass side is working?

Some background:
The dealer I purchased the car from is sending me an element. ( I purchased the car some distence from where I live.)
He believes the problem is the element, but I've not had the car diagnosed, and he is simply guessing.
Why is he guessing? He would like to help me, but dosen't want to pay for the whole job. I purchased the car 'as is' and feel I have no recourse but to accept the help he is offering; such as it is.

I suppose I have to suck it up and have the problem diagnosed. The wires appear in tack under the seat. The toggle switch lights up for both high and low settings.

More seat questions:

Are the pass and drive side seat bottoms interchangeable? They look identical and I'd like to give the pass side some wear while giving tghe drive side some rest.
If I need to replace the element, am I correct in thinking the seat cushion would be accessable?

Again, thanks for the reply.

 

the control unit could very well be at fault, the question is, has either the bottom or seat-back heater ever worked, drivers side of course.

The heaters are wired in parallel so if they both failed at once, it would most likely be the control unit or wiring. If they failed one at a time, then it is BOTH heater elements.

Just curious, what amp rating are those fuses that you looked at? The reason that I ask is that my print shows a 5a and a 20a. the 20a must feed BOTH left and rt seat heat.

As for interchangeable cushions, I don't know, but when you try it you can swap heaters as well and kill 2 birds with one stone...

 

They are: 1=5a, 11=20a.

I've decided to have a pro fix the heating prob. At the same time he'll rebuild the seat with a new pad and springs.

It seems that one cannot just switch the passenger cushion with the drivers. The passernger seat (at least on my model) has the child sensor integrated into the cushion. One would lose air bags permently on passenger side by switching cushions. If one wants to do it anyway, and then try and fool the system with creative wiring, be my jest.