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My blower is only working in postion 3 i have swapped the leads round but only that lead will work on any of the sockets ie 1 & 2 whereas the other leads will no work in the other positions

any idea's

new motor !!!!!

[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry


John

No. The three positions introduce different resistances into the circuit to vary motor speed. Fault likely lies in the 2 failing switch contacts. If the motor works at one speed it will work on the other if they are correct.


TR7 Spider - 1978 Spifire - 1976 Spitfire - 1988 Tercel 4X4 - Kali on Integra - 1991 Integra

Or it might be that the two resistor coils are short-circuiting.
They are situated at the top of the ventilator housing ...



... with the two coils inside, hanging in the fresh-air-stream.

<center>
<font color="blue"><i>1981 TR7 FHC Sprint (better known as 't Kreng)
1980 TR7 DHC (my first car currently being restored)
In parts a 1980 TR7 PI DHC, 1981 TR7 DHC, 1981 TR7 FHC</font id="blue">
<font color="red">http://tr7beans.blogspot.com/</i></font id="red"></center>

Hi John, it might be corroded connectors providing too much resistance for the lower speeds to operate. I had the same problem and did these things which worked for me. I checked them again when rebuilding my heater last week.

1 Connections to motor on the left hand side of the heater box. Stick your hand up there and you'll find the green or green / black wires (I think) that connect to the motor. You can't see them unless the dash is removed but you can run your hand up the cables from the speed controller to find it.....Move the female connectors up and down on the male tab to clean up the connection. Note - the heater box is upside down in this pic



2 Remove the fake speaker panel from the top of the dash to find all the connector blocks. One of the smaller ones and most likely at the top left is the heater block. Green / green black wires again I think. Pull apart and clean / check for corrosion and correct position of pins / tubes in the blocks. Don't pull the wires too hard as there isn't much slack as the motor resistor panel is very close by at the top of the heater. Damage this and the dash has to come out..........

One of the s/hand heater boxes I bought had fried 2 of its resistors on this panel. Hopefully this hasn't happened to yours. Easy to replace in the top of the heater box itself, the bare resistor wires are in the fresh air stream, but the dash has to come out.......

3 I don't know if this helps connectivity but if your heater levers have become sloppy they can be tightened up easily with a small hammer and dolly. Remove the dash cover from the heater lever section and just tap both ends of the shafts gently together and they will close up. This firms them up and restores the friction required to stop them free falling on their own.



Hope this helps.


Adam





TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights. S/S Heater Pipes. No Door Stickers. Mine since July 1986, V8 from 1991

fantastic

you've gotta just love this forum thanks everyone


sorted

[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry


John

John,

"Sorted"

Does that means you fixed it already?

Yep fixed already

from the posts it gave me a clear set of prcedures to follow so i simply took the radio out and proceeded to check and clean every connection.

and viola it worked (for Now) as i still think there is an underlying problem here, i know for sure that the fans okie dokie and the switch is good what i'm not convinced on is the resistance coils, although they looked ok if the problem returns i might swapp these over with a new set

but for now i'm sorted.

as for the speed that i achieved this i was reading your last post whilst in the process of going through the items as i had the laptop on within the garage [:D]

[8 whole cylinders worth of punch to ram the world through the windshield and out the rear view mirror. Car & Driver]
1981 Grinnall TR7 v8
1981 Black FHC
1979 & 1980 Black Premium FHC(laid to rest) Sorry


John

Does anyone know the value and rating of the resistors to get replacements?

I've never seen the ratings and they're not available separately. Basically there are two bare coils of resistance wire soldered to a small circuit board. This is located at the top of the heater box with the bare coils in the air stream, as per Beans's photo. I presume there's no 3rd coil as no resistance is needed for the top speed.

The circuit board and wiring harnesses are listed as available by Rimmers et al etc http://www.rimmerbros.co.uk/Item--i-AAP281

Adam



TR7 V8 DHC Jaguar Solent Blue. 9.35cr Range Rover V8, Holley 390cfm, JWR Dual Port, 214 Cam, Lumention, Tubular Manifolds, S/S Single Pipe Exh, 3.08 Rear, 200lb Spax & PolyBushes all round, Anti- Dive, Strut-Top Roller Bearings, Capri Vented Discs & Calipers, Braided Hoses, 4 Speed Rear Cylinders, Uprated Master Cylinder & Servo, AT 5 Spokes and Cruise Lights, S/S Heater Pipes, Replacement Fuel Tank. No Door Stickers. Mine since July 1986, V8 from 1991