DR3A Wiper motor test

[Grahamgl]

Good evening,

I am currently in the process of replacing the wiper wheel boxes on my 4A. As I am going to have to make a new rack tube, the one from the wiper motor to the first wheel box, I want to be able to test the operation of the wipers before I re-fit the dashboard et al. Can someone please advise me how to Jury rig the wiring from the disconnected battery to the wiper motor as I do not want to put power through the loom with all the loose cable ends being exposed.

Thanks

Graham

[peejay4A]

The colours might be different on your car but this is how mine works. The case of the motor is earthed. The green wire has a permanent live supply to it (normally via the ignition switch). When you connect the green, if the motor is off park it will run to the park position. To get high speed connect the Red/Green wire to earth. To get low speed connect both the Red/Green and the Brown/Green wire to earth.

 

If you're replacing the rack tube from the motor to first wheelbox I strongly advise you to get hold of a second hand one as I could not get a new one to bend in the right places. It's not a particularly complex bend but unless you have a pattern to work from you'll likely have great difficulty in getting the motor installed properly.

 

Best of luck.

[JANA]

Graham,

 

When you do come to refit wiper boxes, they are very awkward to assemble with the flared end of the tubes in the exact position in the wiper boxes, and holding, while you attempt tighten the fixing screw.

 

Someone on this forum , from Belgium I think ? , gave me a brilliant tip! Use an elastic band round the wiper boxes to hold evrything in position, and this leaves your hands free to do the necessary. It really helped me , and I didn't have to get a Gynecologist to do it after all. There is very little room if you have big hands ! Great help to me .

 

Incidentally, my wiring is the same as Peter /Peejay if that helps. The curve as Pete says is simple , but it has to be spot on to locate with the motor. A pattern would help you a great deal I think ?

 

Goodluck

Bob.

[tthomson]

If you are testing your wiper motor on the bench, it is important to follow exactly what Peejay4A suggests. for Slow speed both Red/Green and Brown/Green must be earthed. If you only connect Brown/Green, it can seriously damage the motor. (A few seconds won't hurt, but any more that that will cause a problem). This also has implication for the wiper switch, which must earth both wires when slow wipe is selected.

 

Good luck

 

TT

[Grahamgl]

Thank you Peejay4a and Bob for the wiring advice. I know that the wiper motor works as it has been rebuilt and was used on the RBRR and subsequently. The task I have in hand is changing the wheel boxes and, following the advice above, I have obtained a good second hand rack tube, wiper motor to first wheel box. What I want to do is check the running of the wipers through the new wheel boxes using the wiper motor before I put all the dashboard back and do not want to do this through the car's loom as there are numerous loose wires under the dash. The electrical test will be done after the load to move the rack cable has been measured.

[JANA]

Graham,

 

I well understand your concern to ensure 'all is well' with the wipers before putting the dash back having just gone through that process myself this winter. It is time consuming and tedous , but , a great opportunity to sort out all the wiring and parts that PO / Repairers didn't quite get right. I also used the situation to strip and clean Gauges etc. No regrets as it proved very worthwhile ultimately.

 

Don't forget to set the park facility on the wiper motor when you get to the final leg. ( round cap on the motor held by 3 small hex. headed screws)

 

Hope you feel it was all worth it in the end, I did!

 

Good Luck.

 

Bob.

[Grahamgl]

Thanks for the advice chaps. Rack tubes and wheel boxes installed and operationly tested. Dash re-installation started including under dash tidying.

Graham