Sunroof opened by itself while driving

[Mr. C]

today the sunroof opened completely by itself while I was driving.. It wouldn't close using the buttons. I only managed to close it from the button with the engine switched off and key on Acc position after a few tries. Than when I started the engine on it opened again..drove 2 min in the cold weather (-2 C in London) until destination where I managed to close it in the same manner with the engine off. I did notice a sound like an electric motor that keept trying to operate even if I wasnt pushing any button and sunroof already open. I called the AA and the mechanic tried to disconect the switch, couldn't do it. Than he called his advisor and came back with the proposal to take all headlining off to disconnect the electric motor. (he was told over the phone that there is no fuse relating to the sunroof and it could be the sunroof control module that might be at fault) I didnt let him take the headlining off - he worked really raugh..He was looking for a 3rd fuse box (He didnt even know about the one in the boot!). When I started the engine after the AA guy left, I got lucky: It hasn't opened again (maybe he disconnected or moved some wires around the switch) I am too scared to try pressing any button arround the sunroof now as it would be ridiculous to drive around with it open in this freezing weather. I stopped by Halfords and bought a roll of ducktape.. just in case it opens again - and I need to tape some plastic over it until i get home.

Anyone experienced this? Any advise? I searched a bit the internet and it seams some VW and BMW owners experienced it too. They talked about shorts in the switch or the wires between the switch and motor.

[devilmaycare]

I've never experienced this on my 300C, but I have on my elderly Audi A4. The problem on the Audi is not uncommon and is down to dirty contacts on the rotary switch which make or break with road vibration, so could be similar problem with 300C. I know the Audi switch can be removed without disturbing the headlining and would have thought the 300C would be similar. One nice touch with the Audi, which appears to be missing on the 300C, is an emergency "Allen" type key to close the roof manually in the event of electrical problems, although I've never had to resort to this in 16 yrs.

[Mr. C]

Originally Posted by devilmaycare

I know the Audi switch can be removed without disturbing the headlining and would have thought the 300C would be similar. One nice touch with the Audi, which appears to be missing on the 300C, is an emergency "Allen" type key to close the roof manually in the event of electrical problems

The AA tech removed partially the map lights/sunglass storage subassembly he couldn't manage to get clear access to the back of the switch, but I think with patience, experience and good hands one could do it. Than his next try was to disconnect the motor for which indeed the head liner needs to come off. And yes, other cars have the manual back-up system, the Grand vitara had it..Not really impressed with this particular AA guy..He asked me about the manual..

[devilmaycare]

Originally Posted by Mr. C

(he was told over the phone that there is no fuse relating to the sunroof

I think this is correct. I could find no reference to any fuse in the manual, so if there's a short or overload, the component or wiring just fries!

[Petman]

Fuse is listed as number 44 in the boot 20amp.....was the temp below zero, maybe some condensation froze in the module and made a contact

[DESIREE]

For what it may be worth, here's a description as to how to gain access to the sunroof control module and its attached wires in a north American-built 2005 300C:
To remove the overhead console from the overhead console compartment, place finger tips at rear edge of overhead console and pull down until the rear clip releases. Then go to the left and right sides and do the same. Then pull about 2” of wire harness into the overhead console compartment from within the headliner to allow the overhead console to come down and gain access to plugs. The white plug and the black plug are held in their receptacles by clips that need to be squeezed to release the plugs from the sockets. The plug on the end of the orange wires plugs into the socket of the sunroof switches. A small, thin screwdriver needs to be inserted next to the plug to back-off the retainer clip to allow the plug to be extracted.

[devilmaycare]

Originally Posted by Petman

Fuse is listed as number 44 in the boot 20amp.....

Confirmed! Don't know how I missed this one, although it is the last item in the list. I did think it odd not to have this component protected.

[ivanford]

Some of these breakdown personnel are absolute butchers, shouldn't be let loose on a wheel barrow. A friend of mine recently had his bike badly damaged when the recovery guy jump started it with a 24 volt commercial vehicle supply.

[UK CHRYSLER 300C]

You should never jump start a bike with a car battery with the car running or with thick leads,cheap thin leads and the car turned off is ok.....I think the recovery guy would have known just to use one of his batteries to jump it .....unless he didn't know about bikes of course

[badgx]

Originally Posted by Mr. C

today the sunroof opened completely by itself while I was driving.. It wouldn't close using the buttons. I only managed to close it from the button with the engine switched off and key on Acc position after a few tries. Than when I started the engine on it opened again..drove 2 min in the cold weather (-2 C in London) until destination where I managed to close it in the same manner with the engine off. I did notice a sound like an electric motor that keept trying to operate even if I wasnt pushing any button and sunroof already open. I called the AA and the mechanic tried to disconect the switch, couldn't do it. Than he called his advisor and came back with the proposal to take all headlining off to disconnect the electric motor. (he was told over the phone that there is no fuse relating to the sunroof and it could be the sunroof control module that might be at fault) I didnt let him take the headlining off - he worked really raugh..He was looking for a 3rd fuse box (He didnt even know about the one in the boot!). When I started the engine after the AA guy left, I got lucky: It hasn't opened again (maybe he disconnected or moved some wires around the switch) I am too scared to try pressing any button arround the sunroof now as it would be ridiculous to drive around with it open in this freezing weather. I stopped by Halfords and bought a roll of ducktape.. just in case it opens again - and I need to tape some plastic over it until i get home.

Anyone experienced this? Any advise? I searched a bit the internet and it seams some VW and BMW owners experienced it too. They talked about shorts in the switch or the wires between the switch and motor.

You may have a faulty switch, that's the button on the overhead console or even a relay. For the time being, close the sunroof and pull the fuse to stop power to the sunroof. Wait till summer when the weather is better then you can investigate further