Morris Minor Owners Club

I have a 1970 Traveller with the late type heater
It doesnt work.

It appears to be an earthing fault, I have a 12 volt feed going in on the green and yellow wire that goes directly into the heater motor. I assumed it earths through the body of the heater and the bolts that hold the heater to the bulkhead the bolts are earthing to the bodywork. But no dice there appears to be no earth at the connection on the motors. Can someone shed any light on this?

No it does not earth internally.
I can't speak from personal experience, as my SII has an after market heater, but I do know the instructions in the Workshop Manual for fitting this latter type of heater state:

I had a similar issue and it turned out to be a faulty switch. The heater had to come out anyway for a spruce up so I replaced the switch while I was at it - and yes that's how Ted's heater is wired up, I thought it odd to be connected to the wiper switch.

I thought it odd to be connected to the wiper switch.

Indeed. I'd have thought a good earth to the body would work / be all that was required?
Best wishes,
Mike.

jagnut66 wrote: ↑Mon Jun 13, 2022 12:00 am

I thought it odd to be connected to the wiper switch.

Indeed. I'd have thought a good earth to the body would work / be all that was required?
Best wishes,
Mike.

Only if they were designed that way with a earth connection from the motor return brush to the casing, such as the way the Dynamo is wired up.
If you look at comparable heaters of the time, such as the quite similar looking Mini one, it has 2 cables.

My Tudor after-market has 2 wires, as does the classic Smiths Round heater.

Generally, simply relying on an equipment casing to vehicle body for the earth return connection does not work out well for manufacturers. They do not have any control over the quality of the metal to metal connection. The Fuel Pump earths internally, yet they found it necessary to provide it with a separate earth lead.
It's different with the Dynamo or Alternator; they have comparatively massive mounting bolts to their brackets and engines typically have significant metal to metal mating surfaces.

.

Thanks one and all for the advice