Replacement Wiper Motor

[RogerH]

Hi Folks,

as per my other post my water pump seized and left me with some spare time by the side of the M40 - deep joy.

 

However prior to my grinding to a stand still the wipers were playing up.

I had them looked at last Summer and they were working fine up to a few months ago but then became erratic.

 

So I took the plunge and bought a TR6 wiper motor from ebay.

This is where the problems start to build up -

1 - Obviously it has the self park switch - does anybody know the colour coding to the switch.

2 - Will it work with the TR4A push/pull switch

 

3 - I believe that the gearwheel inside is for 150' I assume the one from my 4A (120') will fit.

 

Roger

 

 

[Nick Jones]

Hi Roger,

 

Being ignorant of TR4s..... I assume you started with a "square" wiper motor (two speed version?) and now have a round one?

 

I went this route on my Vitesse and found many challenges.

 

Mounting method is different (though maybe not on the TRs?)

Wiring is different especially the self park circuit - definitely not plug and play. http://www.s-v-c.co.uk/wiper-systems/

Gearwheels are different and not interchangeable between types. The wheels are available new in many flavours though.

http://www.s-v-c.co.uk/product/14w-wiper-drive-gear/

 

I did get it all working in the end but actually don't find the second speed much benefit (Vitesse originally single speed). Would probably have done just as well well to refurb the original motor and clean/grease the rack and wheelboxes as I suspect the latter was what gave the most benefit!

 

Cheers

 

Nick

[keith1948]

Hello Roger

A cautionary tale regarding a playing up wiper motor. Mine on the 4A was slow, erratic and occasionally stopped altogether. So I fitted a recon unit. Still had the same problems. Eventually tracked down the problem to a loose fuse in the fuse box. Cleaned the holder and fuse, closed the bits that hold the fuse a bit and hey presto fault has disappeared. Suggest you trace the wiring and check and clean all the contacts. On the 4 and 4A the heater, flasher units and the wiper supply wires all join at the voltage stabiliser. The supply wire then goes back to the fuse box. There is also a bullet connector that links the wiper circuit to the flasher unit and optional reverse light switch. This is located under the dash above the steering column and is very difficult to find. It just "appears" out of the wiring loom. Obvious when you eventually find it. Also check the earth to the wiper motor.

The problem with the loose fuse connection was that there was then insufficient power getting to the wiper motor especially when the heater was switched on.

 

Switch 3477 on my 4A has black earth wire to pin 7, red/LG to 4 and Brown/LG to 8.

Pins arranged as below

 

1 2

3 4

5 6

7 8

 

For fast speed switch connects 4 to 7

For slow speed (2nd position) switch connects 4 and 8 to 7.

 

At the wiper motor end the green wire is the supply direct from fuse box via voltage stabiliser connection as described above.

The red/LG wire from the switch connects to the red/LG wire on the motor, brown/LG to same on motor. Black wire from pin 7 on switch goes to earth. Black wire on motor to earth. Basically the switch is used to earth the red/LG and brown/LG wires to the black earth wire that appears out of the loom with these wires next to the wiper motor. Took me a while to figure this out. In the wiper motor the fast speed wire (red/LG on mine) also connects to the self park as well as direct to the armature. The slow speed requires both the red/LG AND brown/LG wires to be connected via the switch to earth. At the motor the brown/LG wire connects (on mine) between the high speed resistance and field winding. I keep referring to how mine is wired. Other cars may be wired differently depending on what previous owners have done ( or bodged).

 

So

White wire from ignition to fuse box, Green wire from fuse box to voltage stabiliser B terminal. From same B terminal connection on stabiliser one green wire goes to the heater fan unit and the other goes via double bullet connector under dashboard to the wiper motor. (you will see 3 green wires on the B terminal, one is the supply from the fuse box). The other green wire at the double bullet connector goes to the flasher unit. Where the loom appears through the bulkhead next to the wiper motor you have 4 wires coming out of the loom. Green is the supply, red/LG and brown/LG connect the switch to the wiper motor and the black is the earth from the switch that is grounded next to the motor. There is also the black wire from the motor that should be earthed on the inner wing.

 

Hope this all makes sense 'cos I'd hate you to connect it up wrong and set fire to the car to add to your worries!

 

Good luck

Keith

[tim hunt]

It never rains but it pours. Actually Roger the TR6 14W type motor has a 115 degree drive gear, this does seem strange since the screen is the same as on the 4A. Actually on my car even after fitting a new rack and wheel boxes and overhauling the motor to remove all the slop I could the wipers were prone to override the screen rubber in heavy rain. This is now exacerbated by recent fitment of PIAA silicone wiper blades that have reduced screen friction. I am looking to source a 115 degree wheel for my motor, hopefully to keep the blades on the screen at all times, unfortunately the 14W gear does not fit the DR3A two speed 4A motor.

 

Tim