The 'E' Type Forum

I am trying to determine the wiring for the heater motor. Browsed the forum but could not find a wiring diagram that would explain the available wires on the heater motor on my 66 2+2, which are
1) black
2) Red
3) Yellow
4) Green
I took a picture before taking out the heater motor and it shows that the Green wire is connected to the red wire, whilst the Yellow wire is connected to the Green Yellow wire on the resistor (which was replaced).
Black goes to earth I presume.
Can anyone confirm this?
Cheers
Jan

Hi

Sounds like a PO may have altered things slightly.

The black goes from the motor to ground.

Then there will be 2 feeds from the switch. One for slow speed and one for fast. According to the wiring diagram, you should have Green-Blue going from the switch terminal 6 to the resistor and Green-Yellow from terminal 8.

The output from the resistor would join the Green-Yellow and connect to the remaining motor + terminal.

It sounds like a your green is connected to fast position instead of Green-Yellow. So connect the red to the resistor output, and the green red joined wire goes to the motor terminal. Your Green-Yellow connects to the input on the resistor. I am not sure why you have a yellow. You might want to check which connections are on the switch terminals. That would help you work it out.


It is shown quite well here on this diagram.
https://dl.dropboxusercontent.com/u/849 ... Colour.jpg

Thanks Mark,
The wiring on the heater motor was a bit of a mess when I took it off the car with all the terminals cut of and the green and red wire were soldered together.

Just to be precise
The red and green wire soldered together coming out of the heater blower motor were not connected to anything else in my picture. But then again, this could have been some leftover from the previous owner messing about.
The green blue and green yellow wires from the switch were connected to the same colour wires on the resistor.
The yellow wire coming out of the heater blower motor was soldered directly onto the green yellow wire on the resistor.

So if I follow your instructions, I have a "redundant" yellow wire. Anybody any idea where it should be connected to?

That gets even more strange. At least one of the wires coming out of the blower motor needs to connect to GND. No idea where the yellow would go. Never seen a yellow wire in that area before, or a red for that matter.

Check your switch, and what might be connected there. It definitely seems like a PO has changed things around, so check the connections on the switch first and work from there.

I opened the heater motor.
The red wire and black wire went downwards and were connected-soldered to one bush each.
Upwards on the casing, a yellow an green wire were connected to one side each of the "engine".
Basically on my car, the black wire was indeed earth.
The red and green wire being connected-soldered together allowed/required for the yellow wire to be soldered on top of the green yellow soldering onto the resistor.
I brought the motor to a local car electrician who will try to clean things up and put everything back together, hopefully.
Not in the mood to spend £120 on a new one.
Will keep you posted.