DR2 Wiper Motor

[klm]

Over the next few weeks, I hope to refurbish the Lucas DR2 single speed wiper motor shown below. As I understand, the procedure for adjusting the wiper parking position is by rotating the parking switch cover. As the cable from the field coil to the parking switch is very short I find that it does not allow much rotational movement of the cover. The wiper motor I have looks original including the cable which shows signs of ageing. Is the parking switch cover always placed at the position shown on the photograph and is there another method of adjusting the wiper parking position?

[mogbob]

Kim
In a word ....no.
What you can do is to replace the wire with a slightly longer one.It MUST be of the same thickness, not smaller.
It is frayed anyway and the wire is exposed... not good !

Very gently prise open the metal retaining tag.Heat up the solder with a soldering iron / gun and release the old wire.
Do the same at the other end and use the old wire to measure a slightly longer new replacement.

Another tip is that the insulator, that helps to keep the brushes separated, is fairly fragile and breaks easily.Don't go at it " like a bull in a china shop ".Treat it with reverence. (I was having a bad day....OK ? that's how I know )

Bob ( born under the Star sign of Taurus... the Bull )

[bmcecosse]

The standard wire is obviously long enough to do the job - so why do you think you need a longer one?

[klm]

Thanks for the responses. I have been looking at suitable cables to use and found the silicone insulated cables to be the best as they are more flexible than the standard pvc auto cable. How much current is this cable required to handle? Can this current be safely handled in a slightly smaller cable? The reason is I cannot find flexible (silicone) cable of the same size as the original.

The insulator to keep the brushes separated was not fitted to my wiper motor. Mine is a 1959 manufacture and Lucas documentation states that insulators were not fitted to early DR2 wiper motors.

[MarkyB]

Flexibility isn't an issue at all with that wire, once adjusted it doesn't move.

[klm]

As the cable originally used is rubber insulated there was a recommendation in a forum on the internet to use a flexible cable rather than stiffer PVC insulated cable. I don't know the exact reason but it could be not to over stress the terminal on the parking switch cover.

From a Lucas technical publication, the maximum stall current that DR2 wiper motor draws under cold conditions is 15Amps. I now need to check if the slightly thinner silicone insulated cable could handle this maximum current.

The grease originally used by Lucas in the gear assembly is not clear although the racks were treated with 'Ragosine Listate' grease from an old British company. I found by searching the internet that the modern equivalent is Shell Turbo 41 grease. A Lucas service manual recommended Duckhams HBB grease to be used in the gear assembly. Does anyone have any comments.

I have completely disassembled the wiper motor as shown below and hope to start the restoration soon.

[bmcecosse]

I doubt you need a very precise grease - just use normal lithium grease.

[klm]

I cleaned the wiper motor by glass bead blasting the main body, aluminium base and end cap, gearbox cover plate and parking switch cover. The main body and other steel parts were protected by applying POR15 paint. The final finish is as shown below. I still need to select the correct cabling and the grease to be used.

[mogbob]

I endorse Roy's grease suggestion any decent Lithium grease will do.Should last you another 20 / 30 years !

Cable size / recommendation.A short length of 28/ 0.30 PVC cable should be used.It's the size most reference books recommend for wipers.
I'm sure you will have a supplier over their but if that's the only cable you need, I'd try and find an Auto Electrician/ Classic car restorer and chat them up.I'm guess they'd give you a short piece for free !!
Bob

[klm]

Thanks Bob and Roy for the advice. Yes, I will use Castrol LM grease and look around for 28/0.30mm cable. I checked the old Lucas recommendations and found that the original cable is 28/0.012" of which the current metric equivalent is 28/0.30mm. Thanks again.

[klm]

I tried to solder 28/0.30 cable to the field coil end and found that it is too heavy for solder to hold. After soldering the bonding broke off when the cable was moved slightly. I trialled with few different sizes and the photograph below shows the heaviest gauge 25A cable tried and on the right is the thinner silicone insulated cable. At the centre is the original cable and I found the flexible silicone insulated cable was successful in holding a sound bond. It is still uncertain if the silicone insulated cable could handle the maximum current through the parking switch.