Strange electronic clicking sound behind dash

[Ecoglo]

Today Ive heard a strange clicking electronic sound behind the dash. Like a stuck fan or switch. It makes a sound both when engine is running and when switched off. 

Anybody have an idea what this is and how to stop it. I had a new pioneer head unit fitted when I bought the car. Could it be this. 

Any thoughts would be helpful..

[John Harrison]

Sounds like it may be a faulty relay???

[Ecoglo]

Relay, as in the heating system?

[dezufo]

2 hours ago, Ecoglo said:

Today Ive heard a strange clicking electronic sound behind the dash. Like a stuck fan or switch. It makes a sound both when engine is running and when switched off. 

Anybody have an idea what this is and how to stop it. I had a new pioneer head unit fitted when I bought the car. Could it be this. 

Any thoughts would be helpful..

It will not be the head unit, it's more than likely the heater/air flow diverter flap motor, the control box has a disc with copper tracks that wear out and then the motor "hunts", the disc can be replaced I think an Avensis or Camry one fits but you will need to check that. the box can be found up behind the dash approx inline with the parking brake pedal

[Ecoglo]

Thanks for this response. It's a mixture of clicks and whirring. Could there debris in the vent?

 

 

[Neil_c]

Sounds like the heater flap motor as dezufo said. Iirc it's called a blend door actuator.

Had similar with mine, I 'fixed' it by pulling the actuator out and opening it up. I can't quite remember how much trim, if any, I had to remove to get to it but a bit of googling will probably see you right.

As per dezufo's post, the contacts in the position potentiometer had worn grooves into the tracks. I just bent the contacts so that they don't sit in the grooves any more and instead are on an un-worn part of the track. That was quite a few years ago and it's been fine since. Well the noise has stopped but I'm not convinced the air out the blowers is the same temperature as what it says on the dash but that might be unrelated...

If you're at all handy with tools etc then this isn't difficult, though getting the actuator out and back in was a bit fiddly.

[Ecoglo]

Thank you. I'm told by the garage that it might be debris that has been sucked in the vent and that it will clear. 

How likely is this?

[Neil_c]

I'm no expert but I would have thought any debris would have to get through quite a bit of the blower system before getting far enough to cause noises you can hear inside the car.

 

Try adjusting the temperature to see if it goes away. Maybe slowly go from min to max and vice versa. If it's wear in the blend door actuator, by adjusting the temperature it might move to a position where the wear doesn't affect it as much and it stops making the noise.

[dezufo]

2 hours ago, Ecoglo said:

Thank you. I'm told by the garage that it might be debris that has been sucked in the vent and that it will clear. 

How likely is this?

Very unlikely as there is, or at least should be, a pollen filter behind the glove box