Clicking behind heater/ac controls

Etheraldreamer · Post by **Etheraldreamer** » 31 May 2011, 16:32

I have an odd clicking sound behind the heating controls in my 98 V70 AWD. It sounds almost like a big relay constantly being tripped. With some experiementations I have been able to ascertain that it stops when the temperature knob is on full cold or full warm but anywhere in the middle will bring the nearly non stop clicking noise. The fan doesn't even have to be on for this to happen and has no effect on it's severity.

Any ideas would be much appreciated. Everything seems to be working perfectly fine, but it is EXTREMEMLY frustrating to listen to at stoplights and isn't something I'd prefer to live with, especially if it points to an imminent failure.

FCPEURO · Post by **FCPEURO** » 31 May 2011, 16:54

It is probably a bad servo motor behind the dash that controls the vents or the thermostat. Are any lights blinking on the from of the ECC when you first turn it on?

Maasai · Post by **Maasai** » 31 May 2011, 19:43

funny that I came across this. I have a 98 V70 GLT and does the same as you described. will try mess with it. was thinking of replacing the dial unit. someone even has this issue on YouTube. Will share if I will be successful.

Etheraldreamer · Post by **Etheraldreamer** » 01 Jun 2011, 09:34

No blinking lights at all. My service lamp is on for an oil change and no check engine lights.

Thanks Maasai, I'll watch for any updates and do the same if I figure it out.

Post by **jblackburn** » 01 Jun 2011, 09:35

Mine does that sometimes if it's cool outside and the AC is on.

If I turn it to full heat, give it a few seconds, back to full cold, and then to the temp I want it at, it will shut up. It is probably a jammed door or something.

Post by **rsavin** » 01 Jun 2011, 10:11

My 94 850 NA with MCC just started this clicking yesterday. My clicking sounds like it's right behind the glove box. Nothing stops it and everything works! Pulling the GB today to see what I can find. Sure won't be hard to locate. BTW I only have to turn the key to pos ll, no need to start the engine .

Post by **JRL** » 01 Jun 2011, 10:25

Jammed flap

Post by **BEJinFbk** » 01 Jun 2011, 11:42

That clicking is pretty much always a flap motor. And the ECC has something like 5 of them.
The ECC can tell what angle a flap is set to at any given time and if the unit fails between
the motor, flap and sensor, the ECC will keep on trying to change a flap angle that's just
not changing. It all depends on what part broke and how. You'll have to open it up and look.
Sometimes they can be repaired, but often need to be replaced when this happens.

Etheraldreamer · Post by **Etheraldreamer** » 01 Jun 2011, 12:17

Great info guys!
Is there a link or somewhere you could direct me for how/what I'm looking for when I get under there?
Thanks again! This forum rocks.