General Heater resistor changed, Still not working

[nickthegeek]

Afternoon all

So I had the usual heater blower only working on number 4 for a while, Then it stopped working completely.
I changed the Heater resistor under the passenger footwell but this has not fixed the problem. I ordered 2 of the resistors as the other half has a corsa so I know it works ok. I've tried to locate the fuse for the blower which is a nightmare in itself.
I found it easier just checking every single fuse instead, Again I can't see any fuses blown at all. Wiring loom 'looks' to be in perfect condition.
So... anywhere obvious I should be checking for this?

I've googled this to death and tried 'I think' everything to locate the problem.
Thanks for you help in advance

Nick

 

[varesecrazy]

So youve got no power getting to the plugs.. or just minimal voltage?

The fan motor should run slowly if fed @6 volts..
but dodgy connections can cut it to 2 volts.. then even the fan you got spinning on a direct feed still wont work back in the loom

 

[Mike1alike]

Does the fan motor work at all? Test it by applying direct DC to it (12V).

 

[nickthegeek]

Afternoon all

Thanks for coming back to me.

I tested the resistor on all 4 points and the plug that goes into it with the dial turned on from 1 through to 4 and showing no voltage at all with the multimeter.
So no the fan does nothing as it is not getting any voltage. I checked the wiring loom for any burnt damage but nothing obvious.

So assumed no voltage even getting as far as the resistor which would lead me to the main fuse. I can't locate the correct fuse for this so just checked all of them

Whats next?
Nick

 

[varesecrazy]

Did you try various earth points?

 

[nickthegeek]

Hi varesecrazy

Do you mean make sure the earth points are clean and not corroded?
The one by the battery is clean as a whistle.

Or do you mean when checking the voltage with the multimeter?

Regards
Nick

 

[OldEngineer]

First thing...
The switching is on the Earth side so you won't get Live on the resistor.
Live goes straight to the motor and then the Earth runs out through the switch and resistor.
Now the main point...
These Heater Motors decline with age and then overload the Resistor. So the real fix is to get a new Motor. Yours has burnt the resistor then seized so it won't even work on position 4

 

[OldEngineer]

The wiring diagram
N085 is the motor. C016 is the Earth point

 

[portland_bill]

The Corsa D, when new had a habit of seizing its heater motor. BSM had four thousand cars on the road at the time, and many had new motors under warranty. And we were changing the cars at 7 months.

As Grande is based on much of the Corsa, you need a new motor. Used to be plentiful on eBay.

 

[nickthegeek]

Thanks for the explanation, That explains the voltage showing on the plug into the fan but not the resistor. So replacing the resistor was worth while also as its probably cooked the old one. Can the motor be changed or is it the whole unit that needs to me changed?

 

[chris3234]

Check the pins on the resistor connector then can get hot and become loose in the plug if they have got hot meaning they don't make a good contact

 

[portland_bill]

https://www.google.com/search?client=firefox-b-d&q=fiat+grande+punto+heater+motor