wiper motor mystery

[lurtch]

Hello PagodaMen,

This may ( or may NOT be ) common on our 40 year old cars.
My windshield wiper motor went  INOP and  blows a fuse every time it is operated.

Touching  jumper leads from my battery to post 4 and the ground post on the plug interface got no movement out of the pump shaft. Seems like my motor is fried.

On eBay I found a good one but from a later car.

While bench testing it , and doing plug-in checks, I found some weirdness going on.
Crosschecking several  wiring diagrams revealed that these later ones eliminated
 the wiper motor relay.

Problem now is:  some how this thing is getting 12V  - - -  although my relay is not activated.

The replacement seems to  work fine but the wiper switch will not  shut it off. I am trying several approaches to wire in a temporary "ON-OFF" switch, until I can get the armature rewound on the old one.

Anyone out there have any bright ideas on this pesky little problem?

I can just see my self pulling over whenever  the rain starts  - - - -  in order to plug it in so I can get home!

Comments Please !!      Larry in CA

[Naj ✝︎]

Power to Pin 4 is for parking only, and remains energised when you switch of the wipers.

Try ground and one of the other pins.

One is for slow speed and the other, second speed.

naj

[Allenh]

This may or may not be relevant here.  Inside the gearbox is a disc with a plastic insulator that interupts the power from the parking lead.  over time this section gets progressively worn.  It  is possible it has worn through and prevents the motor from parking. 

It would be best to first ensure the voltage is off on the high and slow speed feeds.  If the voltage is turned off, an internal fault would be indicated.

I have repaired two of these wiper motors successfully.  It is not difficult