Wipers gone haywire

Link to a .gif follows.

Greetings, all....lately, my wipers went tango uniform. Nothing happens until they're on the HI setting -- no LO or intermittent wipers at all. When they're on HI, they just twitch. I've replaced the motor, but that seems to have proven nothing, as both motors do the same thing. It doesn't look as though the push rods are moving at all. I can manually push it and watch the wipers move, but this is all I get with the motor running.

Is the fact that I'm missing LO related, or is that a separate issue? What's going on under the cowl here?

Thanks!

https://imgur.com/a/ER7mZ8u

Since you have high speed, that means you have power to the system. It twitches because it's just going in/out of park. There's an issue with either the stalk on the column or the assembly on the firewall.

When you replaced the motor, was it the whole assembly or just the motor itself? Did it include the black box that the wires plug into?

Do you have 12 volts at the grey or green wire when the wipers are on low?

The problem is 99% the black box on the wiper motor. A good used one will fix the issue. If you are good at soldering, you may be able to fix the one you have. They are difficult to disassemble without breaking anything.

When you say "black box" ....are you referring to what functions as a "cap" over the gears, with a circuit board, a plug, and a rotating disc inside it?  It's hard to see what might have gone wrong with it..

BrotherJohn wrote:

When you say "black box" ....are you referring to what functions as a "cap" over the gears, with a circuit board, a plug, and a rotating disc inside it?  It's hard to see what might have gone wrong with it..

Yes.