Intermittent wiper mod

[Dave Canfield]

Hi All,

A while back someone asked if it was possible to make the window wipers intermittent. I looked around and discussed the idea further with some of you. I wasn't going to bother with trying to get a system to work if it cost much money, but I did find a switch that I thought would work. I discovered that the switch was way too much $ but there are cheap knockoffs for as low as $20.
After much research I found a specification sheet for another switch (probably the original switch) that said what the connector block was that would fit the switch. I bought a pair of these connector blocks. The connector block needs the crimp connectors and I purchased these to fill that role.
Next I will cover the connections that need to be made to the switch.

 

[Dave Canfield]

Here are the connections that need to be addressed. The high speed connection can be ignored since we don't have two speed motors in the windshield wipers.
I made a pigtail of the new connector block and tied pins 1 and 2 together. Then I connected them to a 12 volt power source that I found down behind the control levers for the rear remotes. That power is coming from the "acc" position of the starter switch.
I did a temporary hack job for that power connection because I don't have the correct mating connector.

 

[Dave Canfield]

Next I made temporary connections to the original wiper switch connector block. Turns out that the wiper motors have positive power to them, and when you operate the switch to turn on the wiper, you are connecting the coil of a control relay in the roof of the cab to ground. Same thing is happening with the washer motor except there is no relay between the switch and the pump.
This allowed me to test the setup.

 

[MossRoad]

I built my own very similar to this back in the early 80s using a 555 timer chip.

 

[Dave Canfield]

After I found the connections that I needed to properly control the wiper motor and washer pump, I removed the connector pins from the original wiper switch connector block.
Since I could not find a proper connector block that mates to the connector block on the tractor wiring harness I removed those pins from the block and connected them to pins that were crimped on the new pigtail that comes from the new wiper switch. To make the connections reversible should I not like the new intermittent switch I left the original crimp contacts intact and covered them with heat shrink tubing.
In the last picture the two yellow wires join together and connect to the red wire that I connected to the power plug in the connector block down by the remote levers.

 

[Dave Canfield]

Here's a closer look at the connections between the new switch pigtail and the original connector block pins.

 

[Dave Canfield]

Here's the picture

 

[Dave Canfield]

To get the new switch to fit the hole in the console I had to make the one permanent modification. I cut the corners of the switch opening square.

 

[Dave Canfield]

Here's what the switch looks like installed. I have not switched to intermittent for the rear window wiper.

 

[grsthegreat]

Does it work ok?