Heater Rheostat Removal

[Trickydicky]

Does anyone know if you can remove the round heater cover without draining and removing the heater? I have had a look and it seems possible, just wondered if anyone had done this.
The rheostat only works to halfway and I have a spare one I want to fit.

[bmcecosse]

Should be fine , but that' s from many years ago.

[mike.perry]

You will need to drop the parcel shelf to give room to remove the heater and undo the screws securing the heater. When you have unclipped the front of the heater and removed the switch you can carefully bend back the tags and strip the switch.You can then clean off the corrosion and the switch will work fine. If the car is neg earth you will get less corrosion, something to do with electrolytic action

[Trickydicky]

Thanks for that, the switch only works up to half way round then stops powering the fan.I have tried switch cleaner and moving the knob slow to fast a few times to clear any build up on the windings but it looks like a strip down. With the fan at full speed I was also hoping to improve the screen demist.

[mike.perry]

The switch should run from off, fast to slow. Check the Y connector is in place on top of the heater and the demister trunking is properly connected, otherwise it is open the quarterlights.

[Trickydicky]

Thanks again for your advice Mike,tried to remove the the front of the heater after dropping the parcel shelf but as the front is Bakelite and brittle, trying to remove the spring clips I was only succeeding in breaking chunks from underneath the clips. Rather than carry on and risk damaging it further, peering into the heater from the side I could see the wiper and it appears to raise up off the winding of the rheostat at about the 8 o'clock position, tried to press it back on but no luck but it did make the fan turn.

So with what Mike had said in his post earlier regarding electrolytic action my car is wired positive earth. Changing the car to negative earth is a job I had planned to do. So by changing the car to negative earth instead of the fan running slow it now runs in reverse and faster
Sledgehammer to crack a nut.........

Thanks again Mike.

[bmcecosse]

So you now need to reverse the polarity of the fan supply.

[mike.perry]

Having dropped the parcel shelf you should be able to pull the heater out as far as the hoses allow to lever back the ends of the clips. The wires to the heater are joined with bullet connectors, if the fan is turning the wrong way just swap the connectors

[Trickydicky]

Traced and swapped the bullet connectors over. Tried again to remove the heater front but no joy, I don't want to damage it. As the fan is working faster, the demister vents are connected ok I have decided to leave it be, I can live with it as it is (at least it is working)
Thanks again.