Fan switch not working?

[wizard79]

Hi all,

Hope you can help, the fan switch on the right of the Cold/hot switch, the ones that changes the output to the front fans, feet or fan near window is not working. I flick it left to right etc and no change, it is stuck on the front window fan. Is this a fuse or something more serious?

Thanks for your help
Jon

[fitz_vt]

mine does this sometime, all i have to do is start the car get the AC going and then swap it, it changes eventually but it might take its time depending on your car...

[VT-565]

Hi all,

Hope you can help, the fan switch on the right of the Cold/hot switch, the ones that changes the output to the front fans, feet or fan near window is not working. I flick it left to right etc and no change, it is stuck on the front window fan. Is this a fuse or something more serious?

Thanks for your help
Jon

I'm pretty sure they are all vacuum operated, hence why you should hear a slight hiss when you change controls. I'd be looking to see if any lines have become dislodged.

[azzaVT]

Sounds like it might be the vacuum solenoid pack... do the exec' models have them?

[wizard79]

Where would I buy the solenoid pack, and where can I find the pack under the hood? Thanks.

[wizard79]

I see a small hose which seems to be plugged into nothing. It is behind the engine. I guess this may be it?

[Phreddy]

It might also be the vacuum reservoir - many models of Commys - not sure exactly which ones, but I know VR and VS had the reservior up inside the front passenger side mudguard - this has a one way valve which allows manifold vacuum to also be present in the reservoir, so that when the engine is off or under load (when manifold vacuum drops away substantially) the controls will still work. If a line has become disconnected from this reservoir, there can be no vacuum built up to operate the solenoids.

As mentioned, there should be a brief hissing sound when you turn the control knob - if there isn't, there's no vacuum present. That can be caused by a number of things - the reservoir as I mentioned, the main vacuum source line to the control mechanism, or a few other points along the system.

Listen for vacuum leaks - run the engine at idle (there's plenty of manifold vacuum at idle), and listen closely. Stick your head inside the passenger side front guard, in the footwells both sides, and even in the engine bay. If you hear a sucking / hissing noise, try and zero in on it. If you find a line that's disconnected, have a look nearby to try and see where it came from - reconnect it, and see how you go!!

Hope that helps... Cheerz!

[Phreddy]

Ah, just read your last post wizard. I reckon you're on to something there - see if you can spot where it came from - probably around the throttle body somewhere.

[Farlig]

you havent recently switch your stereo have you? sometimes people switch stereos and bump the hoses out and dont put them back in, meaning your vents are on demist, since that is the setting they go to when there is no vacuum.

[accentstencil]

I see a small hose which seems to be plugged into nothing. It is behind the engine. I guess this may be it?

That's the hose that supplies the vacuum. It plugs in at the rear of the intake manifold.

[fitz_vt]

yeah, i think that you'll find thats either a condensation output or a vacuum hose i recently found a vacuum hose leak in mine (fixed it though)

[wizard79]

Yep, all fixed it was the vacuum hose! Learn something everyday, thanks guys!