First project - Wipers

[2manykids4a7]

Hey everybody,

So I am trying to get my 1975 Series 3 109 FFR passed inspection and the latest snag is that the wipers have quit working. I am pretty sure the switch is working correctly. I pulled the cover off the wiper motor, pulled the harness from the switch (light grey in the picture) and got the following results with a test light.

Green wire - always lit
Green/Red wire - bulb goes on and off as the wiper switch is turned left and right.

So, if I am correct in my assessment of the switch then it is the motor right? And this is where I get stuck, do I just replace the thing? Can I test it? Rebuild it? Could it be something else? etc.etc.

Thanks for any input, Steve..

[mechman]

Steve, I'd try disconnecting the drive cable/linkage first, then give the motor a whirl again. You may have a frozen cable or spindle that's keeping it from running. If you disconnect the cable and it still doesn't spin, then the motor is fried.

BTW, did you check the ground wire?

Mech

[2manykids4a7]

Mech,

Thanks for the response.

I will try disconnecting the drive cable (I assume that is the mechanical one coming out the top of the unit) and checking the motor.

This may be displaying my complete lack of knowledge but how would I check the ground wire? I understand the need for a circuit to be grounded but have no idea which wire to check etc.

Thanks, Steve..

[Leslie]

There should be a wire that goes from it to a ring terminal that one of the mounting screws holds against the bulkhead. That would be your local ground for it.

[2manykids4a7]

Leslie,

Thanks, I should be able to get to it this afternoon and take a look. Again I am sure I am displaying my ignorance (but hey that's how you learn right), assuming I find the ground wire, how do I check that it is doing it's job?

Steve..

[mechman]

The easiest way to check the ground wire is to hook your test light to the hot wire at one end and the ground wire at the other. Since you know that the hot is hot, if your light fails to go on then your ground wire is at fault.

Mech

[2manykids4a7]

Thanks Mech.

OK so although it is only a small thing I am pretty excited to have, with much appreciated help from Mech and Leslie, tracked down the problem. The circuit wasn't grounding. You can see the ground wire in the picture below, it ran up behind the dash and ended at a tab style connection on the windscreen when I disconnected and clipped it to the bulkhead everything worked great. So my new questions are these. I know the wipers were working before so for some reason the windscreen was grounded but now isn't, should I be concerned about this and try and fix it so I can use the existing ground? Or should I just not worry about it, change out the connector on the ground wire and attach it elsewhere? I could put a ring connector on it and then use one of the mounting bolts for the wiper motor (this is what I clipped it to temporarily) as a grounding point, or I could create a new one all together.

Steve..

[mechman]

I'd drop a ring connector on it and ground it to a wiper motor mounting bolt, just as you said. That way, if (when) it gives you grief later, you'll know exactly where that ground runs to.

Mech

[2manykids4a7]

Picked up the the ring connector and new wiper blades (actually a single blade that I cut in half and added a clip to one piece) on the way home today. Everything went back together really smoothly and I now have functioning wipers. I will take it for inspection tomorrow.

Steve..