1970 intermittent wipers only working on low speed

I turned the wipers on and discovered I only have low now. I also don’t have the wash function.
It’s possible I did something silly or have a bad switch. I did remove the dash to repaint the lower, but didn’t unplug the switch. Car has original intermittent wipers, but the delay doesn’t work either.
I looked at the schematics and before I dive into it I’m wondering if the symptoms are indicative of an easily solved issue (like the ground needing to be cleaned, the switch being bad, etc.).
Thanks.

Im not 100% on this, but I recall an issue b4 and it was the motor. See if you can plug another one in to test your system.

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When I talked to the original owner of m 70 XR-7, he said he had to do something in the box. I think it was adding a ground. If the simple things like checking the motor and grounds doesn’t work, I’d look for a T.S.B. on it. and or find someone who is good with older electronics.

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Switch must be grounded to dash to work correctly on all positions. And there are alot of moving parts in that switch to fail. The shop manual has a table you can use to check out the switch.

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I fiddled around with it some more. It does the delay and low, so it’s just missing high speed.
I appreciate the responses. I’m going to clean the grounds and see what happens, then go from there.

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Removed the switch and found the ground wire in tatters. The old riveted wire terminal was in pretty poor condition, so I drilled it out and replaced it with a new terminal, riveted on, and a new wire.
Still no high speed, but it needs that ground no matter what. So, I looked at the motor ground and found it was the world’s okayest ground. Fixed that, and still no high speed.
So, I guess I’ll test the motor now since I suspect it’s dying or the magnets have weakened over the years.

The switch gets grounded to the dash directly when mounted, so the wire is just extra assurance. While removed, verify the switch is good using the table in my earlier post before you tear into the motor.

I used your very helpful share of the diagnostic procedure. Couldn’t get it to do anything where the resistance value was, but it looks like that’s for the delay portion. So, I sort of figured I was holding my mouth wrong since the delay and low work but High does not.
Couldn’t get anything but OPEN on my meter.
That might mean the switch is deader than disco. IDK.

You are right, the resistance test is for intermittent and you should see it vary as you turn the knob. Mine was open and unrepairable. Found a NOS switch on eBay. Anyway, if those terminals truly were open your intermittent wipers would never go.

Sounds like your meter might be deader than disco (love that analogy!). Meter battery ok?

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The meter seems okay, but I probably do need to swap the battery for a fresh one.
Looks like replacement switches are thin in number now. I’ll keep my eyes peeled for a spare, but I’m probably just going to rain-x the windshield and keep moving forward getting ready for power tour.
Looking at the schematic, it appears I can feed 12v to the high speed circuit through the switch plug and test the motor from inside the car. Once I can establish the motor is good I can safely conclude it’s the switch. Or, I’m wrong about testing it and will find out.

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Was it the motor?

Yes and no.
It’s possible the motor and switch are bad. I decided to drive it a bit and see how it does, if it limbers up and works again after not being used in the rain for a while. Still only have low, but it was intermittently stopping altogether and then starting again.
I need to do a full test again and see what I see.