Hi all,

 

My car heater heat output is poor even when the car has been run for hours.

I have been told that there is an interior temp sensor somewhere in dashboard that could be faulty.

does anyone know where it could be, if it even exists?

 

many thanks

 

Craig

It does exist, as long as the car has A/C, and is inside the Heater/AC control module. If you look at the control panel, you can see there are some gaps at one point, and there's a tiny fan inside that draws cabin air into the unit across a bead thermistor.  Never heard of one failing, but it is possible, I suppose. Lack of good (hot) coolant flow through the matrix, or heater flap motor playing up are more likely reasons, I think.

You would be able to view the temperature reported by the interior sensor on VCDS if you have access. Measuring blocks within HVAC module. In my version its in MB003 "Temperature at A/C Panel (G56)"

 

Thanks for that, is it easy to check the heater flap/motor?

VCDS will tell you there are faults with V68 flap motor, I think, if it is misbehaving.

Is this different to an OBD2 scanner?

@craigsvrs - Agreed with the discussion so far, with the note that you need VCDS and not a generic scanner to access the ventilation system.

 

There's also an outside possibility that your problem is with the "sunlight detector" centre top of the dashboard, but again you need VCDS to test that.

Yeah, can usually delve deeper. Most OBD scanners will only tell you about faults in a few of the electronic modules, like engine, ABS, etc. as far as I know. But if you can scan the HVAC module with what you have, or can borrow, that's where this stuff will be found.

12 minutes ago, KenONeill said:

There's also an outside possibility that your problem is with the "sunlight detector"

Extremely unlikely, as Climatronic systems that might use this aren't fitted to the Mk1 Fabia as far as I can see.

Ah right,

looks like I need to find someone local who has VCDS, who can scan it for me.

 

thanks for the help.

VRS SE = water cooled EGR. You should be getting warmer quicker than previous model years. Something's wonky. Either a sensor or the thermostat, or possibly an air-lock. There is water in the expansion tank right?

Hi,

 

there is water/coolant in tank.

no warning lights are coming on.

I can be sat in rush hour traffic with gauge in central position but air is cool out of heater vents.

24 minutes ago, craigsvrs said:

Hi,

 

there is water/coolant in tank.

no warning lights are coming on.

I can be sat in rush hour traffic with gauge in central position but air is cool out of heater vents.

 

The heater flap motor has malfunctioned, it's quite common.

Hi,

how do I repair the heater flap motor?

52 minutes ago, craigsvrs said:

Hi,

how do I repair the heater flap motor?

 

I would start by using the search function up in the top right hand corner, but that's just me being self-sufficient and doing my own homework...

ok

Don’t take it personally,he is an arse to everybody.

7 hours ago, Wino said:

If you look at the control panel, you can see there are some gaps at one point, and there's a tiny fan inside that draws cabin air into the unit across a bead thermistor. 

 

 

Wow, I never knew that! I guess that's what this little dusty area is?......

 

Yup.

38 minutes ago, maccy said:

Don’t take it personally,he is an arse to everybody.

 

He didn't, you did.

I didn't, honestly.

hi,

 

just a follow on from heater problem,

heater flap is moving as I can hear a different noise when changing from hot to cold.

heater output is getting warm while driving but goes cold if you stop in heavy traffic.

could the water pump or thermostat be at fault?

 

temp gauge on dash always goes up to centre position even when in heavy stop/start traffic and air temp drops in car.

When was the cabin filter last changed? Just wondering if it's blocked.

about a month ago.

Ah, OK.

could it be the water pump as I think its the original one?