Heater blower motor
Discussion
Paulprior said:
I will give it a go, but not very optimistic, the resistance from motor supply to earth is very high but resistance across the 3 speed options is only 2 or 3 ohms, does anyone know if there are 3 sets of windings or just a set of 3 resistors feeding a simple motor?, 3 resistors for the speeds would explain my readings, i looked at how to access it today, not looking good, theres so much of what looks like white silicon holding that cover in place, i will remove the battery tomorrow and have a better look.
I also looked at the flow valve to the heater matrix, it moves nicely so i guess there must be an air lock causing the return pipe to stay cool, i guess i need to rip it all out and have a look, is there any other way apart from removing the pipes and putting air through it to test for a blockage?
There should be resistors at the back of the motor.I also looked at the flow valve to the heater matrix, it moves nicely so i guess there must be an air lock causing the return pipe to stay cool, i guess i need to rip it all out and have a look, is there any other way apart from removing the pipes and putting air through it to test for a blockage?
Yellow wire is high speed so would be best to confirm the motor runs. In later cars this is the only wire used as the speed control is done in a module in the dash.
If the air lock won't clear disconnect both pipe and run a garden hose to one of them. When you have a good steady flow (and worth flushing it in both directions for good measure) clamp of both ends so the pipes remain full then reconnect them where they belong.
Steve
Paulprior said:
Can i access these pipes any where else apart from up inside the left of the passenger footwell, it doesnt look so easy to refit the pipes without loosing the coolant there?
Paul
No, I meant in the engine bay.Paul
Just flushing the heater from the footwell will not clear air in the rest of the pipework.
Steve
A slight re-working of the original question from me; namely, how likely is it that the blower motor itself needs changing/repairing?
Having replaced the 2amp fuse in the blower control box and having a working fan for 1 hour, it subsequently gave up the ghost again. My assumption is that the blower fan is old/gummed up and is creating too much resistance and subsequently blowing the fuse. If it is a change of blower fan I assume passenger footwell and bending into a pretzel shape to get to it will be required?!
Having replaced the 2amp fuse in the blower control box and having a working fan for 1 hour, it subsequently gave up the ghost again. My assumption is that the blower fan is old/gummed up and is creating too much resistance and subsequently blowing the fuse. If it is a change of blower fan I assume passenger footwell and bending into a pretzel shape to get to it will be required?!
See if you can find the connector in the footwell as described earlier in this thread and put fused battery voltage on it to see if it will run ok.
If you run it for a while it may free up.
If it runs ok you need to check the voltage supply to it.
Horrible job getting it out though so good luck.
If you run it for a while it may free up.
If it runs ok you need to check the voltage supply to it.
Horrible job getting it out though so good luck.
After two mended control boxes and various other fixes, Mat Smith had to change mine a few years ago. It's in the side wall of the car, by the passenger's left foot. It's an awkward sod to get out, and they don't make that model of fan any more, so you need to get a suitable alternative.
While you are in there, check the heater matrix isn't clogged up with rubbish from the roads.
Mine was, and after Mat had cleaned it I had a lovely toasty heater for the fist time in my ownership.
While you are in there, check the heater matrix isn't clogged up with rubbish from the roads.
Mine was, and after Mat had cleaned it I had a lovely toasty heater for the fist time in my ownership.
Thanks for the info, I’ve pre-ordered one from these guys https://racetechdirect.co.uk/ who have been awesome (and are 10 minutes from me); I’m just screwing up my courage before the rummaging around in the footwell. I’m clearly going to have to fix the fuse under the dash again, another PIA job!
QBee said:
After two mended control boxes and various other fixes, Mat Smith had to change mine a few years ago. It's in the side wall of the car, by the passenger's left foot. It's an awkward sod to get out, and they don't make that model of fan any more, so you need to get a suitable alternative.
While you are in there, check the heater matrix isn't clogged up with rubbish from the roads.
Mine was, and after Mat had cleaned it I had a lovely toasty heater for the fist time in my ownership.
While you are in there, check the heater matrix isn't clogged up with rubbish from the roads.
Mine was, and after Mat had cleaned it I had a lovely toasty heater for the fist time in my ownership.
I read this thread with interest because my fan doesn't work either I have the later aluminium switches with the ribbon cables. The light to the switch does work however. I checked all the connections at the black box (heater control unit) - all absolutely fine with no signs of over overheated wiring, checked fuses 14 and 16 - all ok. Checked the connection on the left side passenger footwell (a few inches infront of the door and found this (all taped together with electrical tape
There's the 4 wires coming out of the footwell wall, connecting to only 2 wires in the other connectors. The two blue wires weren't connected to anything, and neither were the white and white/pink wires...
It isn't meant to be like this surely - or has Stevie Wonder been trying to fix the heater before? When I look in the passenger footwell and see the loose wiring, random relays on the end of said wiring, and a fusebox bolted to the wheel arch with one 13mm nut, a cold shiver runs down my spine...
There's the 4 wires coming out of the footwell wall, connecting to only 2 wires in the other connectors. The two blue wires weren't connected to anything, and neither were the white and white/pink wires...
It isn't meant to be like this surely - or has Stevie Wonder been trying to fix the heater before? When I look in the passenger footwell and see the loose wiring, random relays on the end of said wiring, and a fusebox bolted to the wheel arch with one 13mm nut, a cold shiver runs down my spine...
Soooo.... I have finally accessed the TVR passenger footwell. The blower motor works fine on 12V direct, Fuse 14 is good and the output from the control box varies (not sure what the figures should be but I get 8.5V to 10.5V) and yet connecting the 2 together results in no whirring from the damn thing. What could be my problem (other than not really understanding electrics very well!)?
Belle427 said:
Have you inspected the control box connector?
The most valid comment.Many before you have found signs of burning at pin B1 or even worse that end of the connector melted.
You may have to bypass that pin and wire direct into the box.
Steve
PS You would not expect to get an output from the box as this wire is on the negative side of the motor.
Thanks Steve, I will put the footwell back together and faff with the control box again. Nevertheless if the wires from the box are providing variable voltage (I re-measured and got 10 V to 11.9 V from the plug in the footwell) surely that should get the motor spinning?
I do have a slightly heated looking connector at the pin mentioned btw.
I do have a slightly heated looking connector at the pin mentioned btw.
Edited by djwazza68 on Saturday 20th April 10:25
djwazza68 said:
Thanks Steve, I will put the footwell back together and faff with the control box again. Nevertheless if the wires from the box are providing variable voltage (I re-measured and got 10 V to 11.9 V from the plug in the footwell) surely that should get the motor spinning?
I do have a slightly heated looking connector at the pin mentioned btw.
As I said before the green wire at the fan is +12V the yellow wire back to the control box is from the negative side of the fan so there should be no power at the box. However, whilst I'm quite familiar with electrics I'm not so competent with electronics which is what is happening in the box. Perhaps someone else can explain why you were getting some sort of reading from that wire.I do have a slightly heated looking connector at the pin mentioned btw.
On earlier cars the switch supplied power to the fan via 3 different wires 2 of which went through resistors at the fan to change the speed. Our later cars have the control box which just connects to the fan 'high speed' circuit and the box controls the speed using 'black magic' (electronics...probably a MOSFET or somesuch).
Steve
Edited by Steve_D on Sunday 21st April 12:00
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