E-Type S1 wiper system, help needed

[No Quarter]

First, let me set the scene. This E-Type was bought in the US 15 years ago, and it was not in a driving condition. Buyer took it apart and sold it to me 2 years ago. So the electrical system has not been in use for at least 15 years, but who knows, maybe not for decades…
Wiring is now installed as part of this restoration, and most things work, but the wiper system doesn’t move at all, neither on Slow or Fast.

Part 1, is it the motor, the wiring or the switch:
My guess would be the motor, since neither Slow nor Fast works. I’ve checked the switch / wiring and found the wires creates ground like this:



Which looks about right to me, a constant Red to Park and Brown for Slow and Yellow for Fast. But I’m guessing.
I took the motor off and took the endplate off. First, it looks too complex for me. But I could see the “coles” were not worn beyond usage, and I saw no wire solderings broken. I tried random +/- wiring and with the Red it tried to turn but didn’t and no other combinations had any effect at all.

Part 2, if it’s the motor, repair:
It’s a DL-3 75404D. I’ve just read in the knowledge base about it, but didn’t learn that much more. I did learn that there’s a thermal overload switch on a 75404D. And often the problem is the ground for the Park (but again, mine doesn’t move at all). Any suggestions? I’m usually quite good at these things, but this one has so much stuff crammed in a tiny space I need an instruction where the dots are close so to speak.

Part 3, if it’s the motor, replace:
My faithful local parts dealer says he can’t find me one, I need to ship my old one to England for repair. With Brexit that means twice freight+customs+vat, a small fortune. Any other ideas? And for sure I want to be certain that the motor is in fact the problem before I spend that small fortune. BTW, is the DL-3 used in other cars?

Any suggestions welcome

--
Or of course stay home in the rain!

[Heuer]

These articles from the Forum Knowledge Base may help:
Wiper motor operation DL3 guide: https://www.dropbox.com/s/x7f9u2g650up8 ... l.pdf?dl=1
Wiper Motor DL3 operation and wiring: https://www.dropbox.com/s/hxrf5x1ws1zac ... s.pdf?dl=1
Wiper motor LHD to RHD conversion: http://www.xkedata.com/resources/read/?id=9
Wiper motor operation (5 wire): http://www.mgb-stuff.org.uk/electricstext2.htm#wipers

There is a lot of information in there so always worth a browse.

[No Quarter]

I had plowed the Technical help section first. BTW, 1 and 2 seem to be the same.

[cactusman]

The wiper system wiring is ahem, complex. Providing the wiring colours and connections between the switch and motor are followed it should work. If the park contacts fail open the wipers will stop the minute they are switched off. If they fail closed the wipers will run continually. If they don't run and the wiring is correct suspect either no supply on the green wire to the motor or a motor fault. Id start by verifying 12 volts at the green wire to the motor. It is fed from fuse 7 when the ignition is on. If there is 12 volts then try setting the switch to slow and then ground the red wire from the motor. This should be connected to a red-green trace wire in the loom that goes to terminal 3 on the wipers switch and also the park contacts on the mechanism. Grounding the red wire with the switch in slow should make the wipers run. If they don't then assume it is a motor fault. It may be the thermal cut out inside the motor or possibly the brushes...

[cactusman]

I should add that the above is a series 1 with the park switch on the wiper mechanism central wiper spindle...later series 1 the park contacts are on the motor

[No Quarter]

Good explanation Julian, tested today, motor out of the car. And yes I have park mechanism on wiper arms

No continuity through thermal cut out (in 3C ). So I took it out of the circuitry, put green and blue together. Continuity from green to blue, so my "repair" is ok. Checked all soderings I could find and continuity to brushes, ok.

Then battery, power to green, ground to red. Didn't move. Also tried power to blue

A few sparks present at battery, so checked continuity from green to red, yes, 0 ohm, that's not right, is it? When motor was in the car, it didn't burn fuses though.

So an internal winding problem? Or what do I need to test next?

BTW, what is the plate that sticks out of the metal endplate?

[cactusman]

Hi Mikael. Not sure what you mean by sticking out? Do you mean the brush carrier?

Looking at your picture someone has been there before you...the red evil crimp joint ain't what Lucas would have done.

Suggest you remove the brushes and armature, clean up the inside. Check the resistance of the field windings for continuity. They should be a few ohms and to end but NO connection to the case. If the thermal cut out has died either bypass (but be aware that if the wiper mechanism seizes you will risk burning out the motor) or replace with a thermal fuse (non resetting but it will save cooking the motor) as the original cut outs are.no longer available and there is very little room to fit anything big. Something with a trip temp of around 70C would do. Axial thermal fuses are available with this temp. Radiospares sell a 73C axial fuse rated at.15 amps. Order no is 797-6064. You have to buy ten but They are less than a pound each.
Reassemble and check the armature spins and do check that the wiper mechanism isn't seized...
Hope you get it going...

[No Quarter]

Hi Julian. Haha, the evil crimper is me, a temporary solution shorting green and blue off the thermal switch...

I probably mean the brush carrier, is that also to be cooled?

Ok, so I try to remove as much stuff and measure resistance from one end of windings to the other. And that both ends do not touch housing. Later today

Not too worried about the lack of thermal switch, I think I can own and drive this car for 5 years without being in the rain, it will never be more than 200km from home, my Longchamp does the cross Europe duties...

[No Quarter]

Measured the following:

-Wire connector to where they are soldered on: 0 ohm (remember that blue and green are now connected)
-"Body" to any wire/soldering/winding: no connection
-Blue and green to left brush (missing in picture): 0 ohm
-Red to right brush: 0 ohm
-White to brown winding: 9 ohm
-Brown to yellow winding: 10 ohm
-White to yellow winding: 19 ohm
-From each brush up to soldering: 0 ohm

Reading the DL-3 75404 pdf in Technical part in this forum, my measurements are pretty much perfectly as they should be?

Anything to measure on the rotating thingy? Or what to do?

[Andyp_67E]

If you can repair it yourself then fine.
But if not I recommend Steve Hunt's services, he knows these motors inside out and made a good job rebuilding my S1 with wiper parking switch which burnt out, came back better than new.
For contact details he advertises lucas wiper motors on ebay with his name on the pic.