Refreshing my wiper post

Started by Bigdog, Mar 23, 2024, 05:23 PM

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Bigdog

My wiper motor DR3A works, when I put power to the switch then plug in the 2 wires the wipers start to work but only go half way then back and as soon i put the switch off it keeps blowing the fuse, do these need a rotary switch, I got this Lucas switch which I assumed was the correct one ,help much appreciated

Dormy

Have you got the wiring the right way around. The motor should have an ignition feed and the switch provides a path to earth (like the self parking switch).

Have a look at wiring diagram 8 in the link below: -

Series 2 Wiring Diagrams
"I'm sorry for the man who hears the pipes, and who wisnae born in Scotland."

Wittsend

#2
I have posted up this DR3 wiring diagram a few times - it come from a respected classic car electrical book.



I've bench tested my own DR3 motor and it works well, self parks when it should.

If your motor is not working then it is wired up wrong or there is an internal fault on the auto park switch. Look for something shorting out inside the motor body.

Compared to the later Lucas 14W wiper motors the wiring for this type is really very basic.
 
There is nothing special about the dash switch - it's just OFF or ON.


:screen

Bigdog

On my wiper motor I have 2 wires that go to the switch and an earth from the motor to the body, then I have one live feed to the switch from the fuse panel and that's all I have, is this correct or am I missing something here,

Wittsend

#4
I think you are missing something.

Look at the back of the motor, you will have 2 terminals and am earth point, as per the diagram ^^^.

The fused 12 volt supply goes to terminal 2
Terminal 1 connects to one side of the dash on/off switch.


Post a picture of your motor to confirm or otherwise.



Bigdog

Maybe it's totally the wrong switch, do I need a rotary switch, how does the screen wash connect etc

Bigdog


Wittsend

#7
Your green/red and green/brown wires are confusing you. They are not needed for this motor set up. Forget them. They are for the later Lucas 14W motors.
They are red herrings  :red_herring
Place a wire (green) from the fuse box direct to terminal "2" on your motor. Take a wire from terminal "1" to your ON/OFF wiper switch. The other side of this switch you take to earth. You earth the wiper motor body.
The wipers should now work and auto park (self park) when you switch off.

Forget washers and rotor switches at this stage.

Find a simple Lucas ON/OFF switch and wire that up as per the diagram. Get the motor working without the "extras".

You can work the washers from a separate on/off switch. There's no reason to have them work off the same switch.

As washers were not standard equipment on Series 2s and early 2As owners/dealers had to make their own arrangements.
Rather than a standard ON/OFF switch they would use a push button. Press to work the washer. This is more logical/convenient than a traditional on/off switch.

Later Series 3s had a combined wiper/washer switch. A 3 position switch.

1) = off
2) = wipers on
3) = wipers on and screen wash

This last function of the switch was spring loaded.

Once you have ascertained your wiper motor works you could consider this more sophisticated set up.

Bigdog

Perfect, so for the earth do I connect from the switch to the terminal on the motor that's marked E which I assume is the earth one or do I earth it another way

Bigdog

Also that switch I got is a Lucas on off one so hopefully that will work

Wittsend

You earth the wiper motor body with a wire to an earth point on the bulkhead near by. Drill a hole and with an eyelet secure with a self-tapper screw.

For the dash mounted wiper on/off switch make another earthing wire, from the on/off switch to a point (behind the dash panel) on the bulk head. Drill a hole and secure with another self-taper screw.

You earth motor, and you earth the on/off switch.


 :RHD

Bigdog

Perfect, going to try that now

Bigdog

Perfect wiring description I now have a working motor 👍🤞, my only problem is I seem to have a live feed to my switch all the time, so my wipers can work with no ignition on through the switch is this correct, also,I connected the green wire from no2 on my wiper motor to the fuse as per advice but have I done it correctly, green wire top right as per picture, also wipers only appear to go half way then back is this normal, thanks

GlenAnderson

If your green wire is connected to a permanent live on the fuse box, then yes, it will be switchable all the time. Pick a fuse that is only live when the ignition is on.

Yes, they should move more than halfway.
 

Bigdog

👍, what can I do , look at to make them go more than half way, thanks