4200 Heater controls still not working

Wack61

Member
Messages
4,637
Previously when the heater / A/C hasn't worked jiggling the key sorted it out until it didn't so i've replaced the ignition switch fully expecting it to cure the problem

The car starts and runs ok but heater panel is still dead and I've got what looks like a small cog in the display under the gear select number

Any more ideas on what it could be ?
 

safrane

Member
Messages
12,161
Thats strange... the 'cog' sounds like the <4`c symbol but at this temp it must be a glitch in the system.

Have you tried a A/C reset?

Hold Eco and Re circulate together and turn ignition on system then self checks.
 

Wack61

Member
Messages
4,637
Unfortunately because the buttons are dead I can't access the reset

This is what's on the display

20170722_154322.jpg
 

safrane

Member
Messages
12,161
That indicates faults in the heater / ventilation system.

Presume you have done a full reset via the battery?

Checked the fuses and the connections at the rear of the control pannel?
 

Wack61

Member
Messages
4,637
Thanks for that, I might try a battery reset again, the battery has been disconnected for a few weeks just been charged over 2 days on the ctec then started

I didn't know there were fuses on the rear of the control panel,I'll check that before I do anything else, thanks Peter
 

tcrote5516

Junior Member
Messages
85
There's no fuses on the rear of the control panel. I believe he was referring to checking the three connectors that go to the hvac control panel and checking the fuse in the footwell.
 

safrane

Member
Messages
12,161
As above... but there is also one in the rear of the NIT , but not sure if its linked to the heater or just the sound system.
 

CatmanV2

Member
Messages
30,852
Battery reset, then check fuses. That's the frost warning and a guess that external temp sensor has a bit of a paddy.

C
 

maseratimad

New Member
Messages
16
Afternoon all apologies this is an old thread but I too am now suffering with the same symptoms.

So far had drivers door card off and checked all connections to the external temp sensor, Put multimeter on this connection and when sensor made warm (thumb) the resistance reading changed so that is working ok even though the temp display in dash has all dashes in it ansd nothing else.

Had to pull the fuse out for the air con compressor as this was constantly clicking and didn't want to damage anything.

Checked all fuses and relays and all ok.

Cant HVAC reset as nothing is illuminating, the display on the head unit for fan speed and temp is visible but greyed out and does not change.

had centre console out and HVAC control unit opened up to see id a dry joint on the circuit board but all ok.

Its a strange on as used the car came back an hour later and HVAC system none operation and compressor constantly clicking.

I have been advised it could be the control unit its in the centre console that has failed suddenly but I still have a display albeit greyed out.

Battery reset several times and no difference.

Everything else on the car works as it should.

Any advice or ideas would be most welcome,

Regards

Anthony
 

safrane

Member
Messages
12,161
A few members have found loose connectors behind the head unit which after wriggling brought back normal service.
 

maseratimad

New Member
Messages
16
Hi Safrane, I have had the head unit out and checked all connectors all sound and firmly in place but thanks for advice