Morris Minor Owners Club

I know it seems a stupid question where does the live wire from the heater go ? I have just brought a 1956 split screen moggie and the heater was not working. So I dismantled all the pipe work disconnected the earth wire followed the live wire and discovered it went nowhere. Whilst the heater was out I ran it across the battery and it works fine. I have looked at the wiring diagrams in the old manuals I had with the car but they do not show the heater. Cheers

As the heater was an option it's quite likely it wasn't shown in the normal service manual - usually you can find these details in the back of the manual in the supplements section. However, all your heater motor needs is an earth and an ignition fed live from the fusebox. Check you get the earth and live correct if you have converted car to negative earth as "some" of the old heater motors will run backwards if connected the wrong way round.

The 'reverse running' was recently proved incorrect I believe.........

bmcecosse wrote:The 'reverse running' was recently proved incorrect I believe.........

Quite possibly which is why I said "some" as I don't think we have tested everyone ever made yet
Anyway, as the heater is out of the car it will be an easy check to make.

I have recently traced the heater wiring on my 1956 splitscreen and the live heater cable runs from the voltage stabalizer on the instrument panel. This is shown in some circuit diagrams but others show it connected to the fuel guage. Its operation would not be affected by these instruments it is just a convenient place to spur off a live feed. The blower motor on my smiths heater will run when the polarity is reversed but it runs slower.

Where do I find the voltage stabalizer on the instument panel ?

You haven't got one. On the 1098 cars with black dial the stabilizer is bolted on to the back of the speedo.

It's the little box on back of speedo - with the green wires attached - you want to take a connection from these green wires!

So would it be okay to take a connection straight from the fuel guage ?

bmcecosse wrote:The 'reverse running' was recently proved incorrect I believe.........

Not on my '66 Traveller. Reverse the polarity and the motor does indeed change direction. I have just changed a faulty motor for a used spare. Both of the heater fans have an arrow showing the direction of rotation and one of them even has a sticker showing which direction goes with the appropriate polarity

Indeed! I am v surprised. But if you have done the test....

lesrollins wrote:So would it be okay to take a connection straight from the fuel guage ?

If it is an unregulated supply (ie full battery voltage) then yes....

AndySSS wrote:I have recently traced the heater wiring on my 1956 splitscreen and the live heater cable runs from the voltage stabalizer on the instrument panel. This is shown in some circuit diagrams but others show it connected to the fuel guage. Its operation would not be affected by these instruments it is just a convenient place to spur off a live feed. The blower motor on my smiths heater will run when the polarity is reversed but it runs slower.

I'm not sure that is correct-reversing the polarity on a dc motor would not make it run slower. It might sound different due to the unidirectional blades but would run at the same speed just in the other direction and obviously not be quite as efficient-hence appearing to be slower.