• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.
    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

TR2/3/3A TR3 Wiper motor

Share this page

R

rthevenin

Freshman Member
Country flag
Offline
Hi

I've nearly finished the restoration of my TR3.
I cannot get the wiper motor (Lucas DR2) running though.
Before I remove it from the car to clean it and repair it, it was working fine :-(.

When testing it on a bench and put power on the spade connectors the rotor gets 'stuck' on the stator and doesn't move turn. I can also hear a buzzing noise (like electric power lines).

I've tested the commutator with a ohmmeter using the 3 recommended resistance tests (180° , bar to bar, shaft); and obtain similar values.
And when I put power to the commutator, it creates a magnetic field.
So it seems the rotor is in good order.

The stator also creates a magnetic field when connected.

Any idea on what could be wrong with the motor ?
 
Positive ground or negative?

The ground is key. Power from terminal 2 goes to *both* the armature and the field coil, then both back to ground (it's a parallel circuit). Check out the continuity for both of those. Be sure to use a battery, not a battery charger, for power supply.

Here's an excellent reference on rebuilding/repairing that DR2 motor:


Tom M.
 
As an aside, be aware that many wiring diagrams show a live feed (green wire) going to the wiper switch. Wrong! The purpose of the switch is (as pointed out above) to act as a ground
 
I just went through this... Turns out that I had a little extra paint on one of the casings and the motor shaft wasn't EXACTLY centered when I put it back together. Basically, the shaft would not turn or got hung up. Super easy fix. Just be super careful that the re-assembly is perfectly centered. Works like a champ now.
Joel
 
NutmegCT said:
Positive ground or negative?

The ground is key. Power from terminal 2 goes to *both* the armature and the field coil, then both back to ground (it's a parallel circuit). Check out the continuity for both of those. Be sure to use a battery, not a battery charger, for power supply.

Here's an excellent reference on rebuilding/repairing that DR2 motor:


Tom M.
Click to expand...
Thanks Tom.
I'm using a 12V power supply - not a battery charger or a battery. Where should I connect + and - ?
 
Assuming your 12v power supply provides the needed amps for the motor ... positive from the power supply goes to terminal 2. Ground goes to terminal E.

You can see the 1, 2, and E in this photo:

wmr37.jpg
 
Mac, if the car is positive ground, should the negative lead go to terminal 2, ground to terminal E to spin it in the intended direction? And possibly avoid smoke (although I have not thought the smoke issue out yet).
Bob
 
Last edited:
H are two pics of my positive ground wiper motor. HTH!
 

Attachments

  • B59094CF-62C0-4B4C-B75E-18EAEA79A898.jpeg
    B59094CF-62C0-4B4C-B75E-18EAEA79A898.jpeg
    2.7 MB · Views: 81
  • 503312D8-2B51-4962-83B7-9DA71ECE15B2.jpeg
    503312D8-2B51-4962-83B7-9DA71ECE15B2.jpeg
    3.4 MB · Views: 86
I think you will find it makes no difference if it is + or - earth like the starter motor it will only rotate one way.

Graham
 
I put the field coil assembly 180 out once and the motor went back together fine, but would not work. Mine kept blowing fuses until I finally figure out the field case was put together wrong. Could you have yours flipped around.

steve
 
Back
Top