Alfa Romeo Forums banner

1 - 7 of 7 Posts

·
Registered
Joined
·
8,373 Posts
Discussion Starter #1 (Edited)
Uncle hasn't made a career of installing wiper motors...up until now. After hours of chasing blown fuses, paying dearly for rebuilds, and bending the ears of every expert I know across cyberspace and cellular air waves I can now report with certainty there is a God.

The most important thing I learned is there are six ways to connect wires to 3 poles--1,2,and E and there is only one correct one that will operate the wipers, park them, not blow fuses, and burn your house down. The caveat is the ONE way depends on whether your system is POS or NEG ground. They are not one and the same wire connections but are exclusive to each. Please read the attachments in entirety. They are priceless documents. I hope this clears up the misconception that Lucas makes junk and that they are built with shorts in them. Praise God!

"Per common tradition, reassembly is the opposite of disassembly. Maybe
clean the grease off before you put it back in the car. When it's back
together you can test it by applying power + and - to terminals 2 and E
respectively for negative earth, or + and - to E and 2 respectively for
positive earth. Connect terminal 1 to E to make it run. Disconnect terminal
1 to allow it to park. Rotate round cover to set the park position. Park
position will be slightly different running free vs under load, so this may
require a small re-adjustment after installation. " MGAguru.com


Special thanks to Les Hurlock and be sure to open the two attached sites. The MGAGURU is a master of instruction and entertainment


Wiper motor rebuild

MGA fused ignition circuit, wipers
 

Attachments

·
Registered
Joined
·
66 Posts
One note:
Battery Polarity doesn't matter to these Lucas motors, just crossing up #1 and #2 wires will be a short. I run my Giulietta Normale Negative Ground , just switched the coil and re-polarized the generator. I never had problems with the wiper motor afterwards. Excellent drawing of the wiper unit!
Craig
 

·
Registered
Joined
·
8,373 Posts
Discussion Starter #3 (Edited)
One note:
Battery Polarity doesn't matter to these Lucas motors, just crossing up #1 and #2 wires will be a short. I run my Giulietta Normale Negative Ground , just switched the coil and re-polarized the generator. I never had problems with the wiper motor afterwards. Excellent drawing of the wiper unit!
Craig
That's what I thought..it tested fine on the bench with battery poles to either
1+ 2- or 1- 2+. (no E wire)

Put it in the car with no connections and touch BATT lead from the trunk ( -) to 1 and it arced every time with no other connections other than the battery grounded (+) to the chassis.

I followed the MGA guru instructions and Les's drawing and it worked like a champ.. It's all black magic that I am not going to touch again. Somethings I just accept, not many, but if you say my motor will work wiring it the way I have it and only that way and add the world is flat.. I can live with that. . I have seen wiring diagrams either way but it didn't work on my motor either way.
 

·
Registered
Joined
·
126 Posts
Thanks for a great post. I've been battling for months with mine and tried it every which way..... except the right way!
 

·
Registered
Joined
·
4 Posts
Follow-up info for 4-wire 1-speed wiper motors

We're rewiring our '57 Sprint and became somewhat perplexed by the wiring diagram (original from 4/58) that shows four wires each going to the wiper motor and the dash switch. The wiper motor is original to the car; it's a SWF brand with part number SWA3305 stamped on the bottom--see attached photos.

I thought briefly that maybe we had a 2-speed wiper motor; opening up the gear case on the motor made it immediately obvious how it all works. It's a 1-speed motor with two completely separate circuits for ON and PARK operations. Dash switch ON supplies +12V (Green wire on circuit diagram and in the photo) to the motor, which has a Ground (Black) wire to the chassis. Meanwhile, the motor has a separate +12V supply (Red wire on diagram and in the photo) powered with the ignition switch. When the dash switch is flipped to the OFF position, the return wire for the PARK circuit (White/Black wire on diagram; plain black wire in photo) is grounded at the switch to complete the circuit.

Seems unnecessarily complicated, but it all works. I cleaned up and lubed the internals on the motor, which were all in good shape save for the gummy 54-year-old grease. It'll go back in the car today!

Happy holidays to all,

Dave (& Scott) Walker
'57 Sprint Abnormale
'59 Sprint Normale
'59 Spider Veloce
 

Attachments

·
Administrator
Joined
·
4,044 Posts
Sprint wiper systems

Dave, Scott, Uncle R, et al

There were 2 different wiper systems fitted to the Sprints, one is the Lucas worm & wheel job, which is standard on British sports cars of the period, the motor unit is fitted up-n-under the dash on the RHS between the glove box and the A pillar. The fixed dash top makes installation a swine of a job.

The other unit is the SWF which is operated by rod linkages & the whole assembly is mounted to a triangular bracket which in turn is fitted under the middle of the dash.

Ciao
Greig
'57 Sprint 05262 with Lucas worm & wheel
'57 Sprint 05880 with SWF
'58 Sprint V E06193 with SWF
Others
 

·
But Mad North-Northwest
Joined
·
11,120 Posts
This thread was a huge help a few weeks ago in getting my Lucas wiper motor working. It wouldn't park properly, so I disassembled and fixed the broken park switch contact. As soon as I did that, it immediately started popping the thermal fuse each time I used it.

Turned out the PO had swapped the #1 and #2 wires, which works fine only so long as the park switch is disconnected. Literally took me an hour with my head under the dash to get those two little screws and wires swapped: what a PITA! Anyway, it now works properly.
 
1 - 7 of 7 Posts
Top