Heating control unit not working

Dora115

I have a Vauxhall corsa 55 plate (no I'm not one of those chav mobiles!)
My heating unit which controls the rear heated window isn't working. No lights or speed settings work.
Air comes through when driving just slowly and no nose from motor.
I've had the switch changed, a new unit fitted and fuses changed (which where previously ok)
Still no heating?
Help would be great!
Very cold person!!

Marktheshark

Did they change the heater resister ?
A very common fault that causes those symptoms, quite an easy DIY fix with plenty of youtube videos and info on google, new resistor pack and unscrew the old one and slot the new one in, usually under the glove box area.

Dora115

Nope! - the only info I find on resistors is the new shape (corsa d) I shall give this a try! Thankyou kindly.

wrightk

Marktheshark wrote: »

Did they change the heater resister ?
A very common fault that causes those symptoms, quite an easy DIY fix with plenty of youtube videos and info on google, new resistor pack and unscrew the old one and slot the new one in, usually under the glove box area.

Surely if it was the resistor the fan would be working on full speed just not the other speeds? Sounds like the blower motor

facade

What happens on the Corsa-C (I had one) is water somehow gets into the heater, this can be from attempts to sanitise the air-con, or a drainage problem.

The design of the heater is such that all this water collects at the bottom of the motor, and rusts the lower spindle bearing. Then the motor starts to run slow, makes a noise and usually burns out the resistor pack when it seizes.

Changing the resistor pack might "fix" it until the new one burns out (or on a zafira sets the dash on fire)

The good news is that if you take the glove box out, you can remove the motor complete in its housing from the passenger footwell.
Then the motor can be lubricated or replaced. I drilled a couple of 6mm holes in the lowest point of the housing to drain any future water away.

When all is working, you can change the pollen filter by lifting the plastic cover at the base of the windscreen, and check for piles of leaves blocking any drain holes in there.

wrightk

facade wrote: »

What happens on the Corsa-C (I had one) is water somehow gets into the heater, this can be from attempts to sanitise the air-con, or a drainage problem.

The design of the heater is such that all this water collects at the bottom of the motor, and rusts the lower spindle bearing. Then the motor starts to run slow, makes a noise and usually burns out the resistor pack when it seizes.

Changing the resistor pack might "fix" it until the new one burns out (or on a zafira sets the dash on fire)

The good news is that if you take the glove box out, you can remove the motor complete in its housing from the passenger footwell.
Then the motor can be lubricated or replaced. I drilled a couple of 6mm holes in the lowest point of the housing to drain any future water away.


When all is working, you can change the pollen filter by lifting the plastic cover at the base of the windscreen, and check for piles of leaves blocking any drain holes in there.

Good point
Always good to be mindful of the current zafira recall which has exactly the same water ingress/fan/resistor problems too, and vauxhall are doing a scuttle panel sponge 'fix'. Plenty of corsa owners out there not happy too

Dora115

facade wrote: »

What happens on the Corsa-C (I had one) is water somehow gets into the heater, this can be from attempts to sanitise the air-con, or a drainage problem.

The design of the heater is such that all this water collects at the bottom of the motor, and rusts the lower spindle bearing. Then the motor starts to run slow, makes a noise and usually burns out the resistor pack when it seizes.

Changing the resistor pack might "fix" it until the new one burns out (or on a zafira sets the dash on fire)

The good news is that if you take the glove box out, you can remove the motor complete in its housing from the passenger footwell.
Then the motor can be lubricated or replaced. I drilled a couple of 6mm holes in the lowest point of the housing to drain any future water away.

When all is working, you can change the pollen filter by lifting the plastic cover at the base of the windscreen, and check for piles of leaves blocking any drain holes in there.

Thankyou! Mine hasn't got air con etc does this still Apple?

facade

I would have thought so.

I don't know if the fan motor is your problem, but as Wrightk says, usually the motor still works on the full speed setting if the resistor unit has failed.

So it is either a fuse (in which case why did it blow.....) or the motor.

It has been a few years since I had mine, but definitely I got the motor out without any dismantling except the glovebox, I think the screws have torx fastenings, so you need a set of torx keys from a motorfactor.

I had to lie upside down in the footwell to take the motor unit out, a couple more torx screws and a few of those plastic buckles to unsnap if I recall correctly, and then the motor drops down attached to the lower half of the shell.
(It looks a bit like a snail shell sticking out of the side of the heater.

There are plenty of spare motor units complete on eBay for around £20.

It could always be something other than the motor, but if you are able to undo a few screws working upside down in a small space, you can save a fair amount over paying a garage.