Heated seats

[loely]

HI,
Is there a way to activate the switches for the heated seats .The are in the AC control unit but do I have to go to the dealer?Maybe via VADIS ?

Loely

[Antz]

Fit a heater panel with the switches in from the factory. It's thr easiest way. Fitting the switches into a panel without them doesn't work.

[loely]

I do have heated pads but without current arriving at the switch they will not heat,factory pads or not.So how can I get the current at the switches?
If nothing goos in ,nothing will go out.
The switches are original ones fitted in the AC control pannel. Nothing happens.

[flyingtech55]

Fuse?

TimR

[druid]

I looked at my blanks with a view to adding switches but the whole lot needs to be fitted.

[loely]

The switches are pushed into the integrated AC electronic command unit so there is no way of adding somthing more.
I doubt that Volvo wants you to pass by the cash desk at a dealer to activate the switches in the cpu .
Just like ABBA "money money...."
http://www.volvoforums.org.uk/images...smiley-004.gif

[ITSv40]

How I read it: You have a climate control panel with the heated seat switches fitted, but the heaters do not work.

Did the car have heated seats from the factory, if not, is there an unused plug hidden in the loom that needs plugging into the back of the panel/control unit. It could be that cars without heated seats but with ACC do not have all the plugs fitted behind the panel. I'm not sure if this will be the case, just a thought.

[loely]

ITSv40,
That is the case,no original heated seats but on the AC back there is no place to put in a plug and even without heating pads the control lights in the switches should light up (I think) wich is not the case. There is also no place to add a wire in the plugs. Because the switches are pluged in the intigrated circuit it is not possible to add a new wire.
loely

[ITSv40]

I've never tried to do what you are trying, however, I was always under the impression all you had to do was install the heated seats and plug them in to the wires under the carpet. Fit a new control panel with the seat switches and you were good to go.

Looking in Haynes: the power comes via the ignition switch to fuse 6 in the under dash fuse box. A red/white wire then goes to the passenger switch and then on to the seat heater - the drivers supply is piggybacked of the passenger switch. Both seat heaters are earthed - presumably somewhere down under the carpets. Not sure if any of this is of any use, but it may be.

[canis]

I don't actually know, but this is what I'd do if it was me:

Obviously check all relevant fuses. In particular, examine empty slots.

The seat heaters are almost certainly controlled by a relay, probably near the cabin fusebox. The relay is probably missing, if it wasn't specified. With it missing, although the wiring into the AC unit it present and connected (as you say there isn't any holes left unplugged) the actual circuit for the seat switches is all just a bunch of wires which go nowhere, and therefore don't light up.

I'd be inclined to trace the wires from the switches on the PCB to see which wires they connect to, note the colours and try to find the same colours (and wire thickness, number of, etc.) at the relay board under the dashboard. While you're in there, see if the relevant wires arrive at the computer module. If that's the case, it's gonna be more complicated as presumably the relays for the seats will be internal and the logic to control them will be anybody's guess.

Regarding wires; There are big clues to be had by noting the amount of them, the guage of them, and the colours form a kind of code. What you can be certain, is that the wires controlling the logical state (on/off) of the switches will be fairly thin. The wires supplying the heater elements will be thick. The wires supplying power to both will be equally as thick, likely red but don't bet your life on it. Be aware than any current returning from the heating element will be the same thickness as that supplied it. Two seats means two elements, two elements likely means four wires. Examine the seat connectors to be sure. Then find their other ends, which will be where the relay is supposed to be. Y'know, work it out intelligently - two bits of information can yield another third bit.

One thing to check (as I don't know) is if the buttons are a two position type, or momentary action. In other words, if they latch into an 'on' position and then unlatch 'off', the relay is likely a simple one. If they're a momentary action (like the dreaded fog light switches) then there'll be a logic controller, approximately the size of a relay but containing some more electronics to handle the on/off logic. It's not impossible to recreate all this electrickery, but you may find yourself better off buying the module, if such exists - I dunno, I'm thinking out loud here.

The wiring diagrams in the Haynes manual aren't always entirely accurate, but they're better than nothing and can help you verfiy your findings.