heater motor quit

cdnp6

cdnp6

Member
My ignition barrel had some play in it recently which caused it rotate with the key when starting.
This rotating was causing my heater motor to run intermittently.
After tightening the barrel, everything seemed OK. Wiper motor and heater motor both working.
My heater motor has now given up the ghost, although my wipers work fine.
The rubber cover on the spade connector that connects to the ignition switch was a little melted so I spliced in a new connector.
Still, wipers work OK, but no heater motor. Where do I need to look next?
 
Assuming the fuse is good then check if you have power getting to the motor. If you have then there is either a bad earth (possibly the connecting strap for the control lever) or the motor is kaput. If not then check the various bullet connectors in the circuit.
Bruiser originally only had the heaters fast speed working until I changed the heater control which restored her to a two speed heater. I couldn't see anything wrong with the old one though.
 
There is a three-pin connector where the loom goes to the heater blower motor, it's on the right hand side of the heater box on RHD cars. There you can measure, whether there are 12V when you switch the motor on. You can also feed 12V directly to test whether the motor actually works. These motors do fail. It happened to me.
 
I'm not sure if mine has failed. Took the car on its first "long distance" highway drive tonight - 40 Km at 80 - 95 kmh. while at speed, air comes forcefully out of the dash and floor vents, but I can't say that I can hear the motor running. Mind you, I have a manufactured hole in the drivers footwell by the pedal box (my mechanic says this was done somewhere in the past to provide clearance for gearbox removal. Not sure what to think of this), and my soundproofing and carpets are not installed at the moment, so the cabin is somewhat noisy. At idle I can't say that I hear the motor.
Will air come forcefully through the vents if the heater motor is not working?
Is this 3 pin connector in the cabin or under the bonnet? Can you post a pic so I'm sure of what I'm looking for?
Heater motor info seems to be sparse at best in the workshop manual...
 
You will get ram air through the vents when driving at speed, no blower required. The heater motor plug is on the engine side of the firewall on the rhs of the heater box. (from the drivers seat) Just peer down into that dark corner with a torch and you should see some wires coming out from behind the heater into a 3 plug Lucar terminal. They are all brown with different coloured tracers.
Try checking the fan without the engine running. With the ignition on you should be able to hear it going although a good fan is pretty quiet.
 
Thanks for the quick response Kiwirover.
Found the three point connection, all bullets are tight, no sign of overheating.
Dropped right side glovebox, the groundstrap is well connected at both ends.
Checked the two leads from the control lever, again, connections are tight, no sign of overheating.
I ran my finger over the two raised contact points and found these to be quite dirty. cleaned them off which made.... no difference.
I still need to try adjusting the copper slide to see if it needs to make better contact.
The fan should run in the accessory position shouldn't it? If so, I have no fan.
Arrrrgh...
A telling sign may be that I found a spare control in my box of parts.....
Some numpty cut the wires rather than unplugging the bullets. I'll try splicing on some ends and plug this in to the wiring and see if it makes the motor go.
It looks like the control is screwed in from the back, so if I need to replace the control I have to remove the radio console to get to the attachment screws?
 
The fan control switch basically just earths the wires so if you unplug the 2 wires from the switch and ground them one at a time with the ignition switched on, you should be able to rule out the switch as the problem.
Next you need to probe the 3 motor wires with a test light or multimeter. With the key on, one of them should be live. The other 2 go back to the switch. If you have power here and earthing the other 2 does nothing, then the motor is dead. :(
If there is no power, then check all the fuses and fuse box connections 'cos that's where it goes.
 
I can confirm that I do have a working fan... occasionally...
Still does not turn on when the key is in the accessory position, but when driving the car, it will come on every now and then.
I had the fan working at a full stop at an intersection, and at another stop fan was not working.
When the fan was on, I checked it's output in all control positions and in the top position the fan does shut off.
In the run positions, I can't feel much difference in fan speed.
I have checked the ground strap, all connections, fuse and fuse box connections and all seems good, I still have to probe the 3 way connector in the engine bay - one of my to do's this week.
What else should I do?
 
I'm sorry to say that it sounds like your blower motor is probably in need of some new brushes at the very least. Worn brushes will cause intermittent running as you describe. It could still be a bad connection but I doubt it. Unfortunately, the heater box has to come out to get to the fan motor which is a right pain in the @rse on a 2000. I haven't tried it for a long time but I believe you need to remove the rocker cover first.
 
KiwiRover said:
the heater box has to come out to get to the fan motor which is a right pain in the @rse on a 2000. I haven't tried it for a long time but I believe you need to remove the rocker cover first.
Click to expand...

Never had to do that.
 
To be fair, I'm not sure. I've only removed 4 cylinder heaters from cars that have already had the engine out but I know the heater box has to come forward a fair bit to extract the fan lever before it can go up. I seem to recall something in the manual about the rocker cover... but I bow to your superior knowledge Harvey. :D
 
I had a chance tonight to test the leads with a mechanic friend.
The wires in the three way connector tested fine. We took of the metal mesh over the heater box and turned the fan blades with a long screwdriver. This got the fan to run slowly.
My friend moved the wires around to see if that changed the speed at at all, and we were able to get the fan running close to normal speed when he pulled on the live wire going to the blower motor.
So added to the list of things to do is to check the connections at the blower motor.
Is there any way to access the motor without having to fully remove the heater box?
 
I found these heater removal instructions on the Swedish Rover Club website.
They are for a non air con V8. For those who have done this, how do I need to modify the instructions for a 2000 TC?
Anyone got any good pictures of the procedure?

Removing the heater box

1. Disconnet the battery

2. Remove the wipers.

3. Remove the windscreen valance.

4. Open or remove (not necessary but makes it easier) both glove boxes.

5. With a really long extension and a 5/16" socket feed the extension in behind the radio unit from the right hand side while you look and grope on the left hand side to loosen bolts joining the heater forks to the top/bottom - hot/cold levers.

6. Using two 5/16" spanners disconnect the fan lever from the heater box tang.

7. Remove the air cleaner.

8. Remove the coolant hoses from the heater.
9. Disconnect the three wires from the right hand side of the heater box.

10. Undo the four bolts holding the heater box in.

11. Man handle the darn thing out.


You my also need to unbolt the throttle linkage bracket but I can't remember doing that in the V8.

Another thing that can go wrong is the linkage spindle can break internally so that the lever does practically nothing.
 
That pretty much sums it up for a V8. It will make life easier if you remove the bonnet first but that's not essential and the throttle linkage should be fine (at least on a rhd) When you are wrestling with it, you need to try to keep the lower flap closed or it will catch in the vent under the box. Again I refer to the manual which suggests removing the rocker cover and the rear rocker cover stud for clearance as the heater has to come forward before it will come up.
 
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