Attention Electrical Gurus, Need help with windshield washer wiring Options

[bbrock]

Right after ordering a complete Car Magic kit to convert my windshield washer to electric, I read Sir Andy's excellent tech article on the conversion. The idea of pulling power for the washer pump off the intermittent wiper feed so the washer is activated by pulling back on the wiper lever was too elegant not to try.

I happened to have this nifty vintage VW style splitter I bought some time ago for not other reason than I thought it might come in handy for some future custom wiring project. It was just the ticket for splitting off of my intermittent washer relay to power the washer pump.



After hooking everything up, I pulled back on the wiper lever and HUZZAH! The washers squirted and the wipers ran for two sweeps and parked. Pretty slick! I couldn't understand how the intermittent wipers would work when the lever was pulled down to turn the intermittent wipers on. I pull down on the lever to test them and nothing. As soon as I unplug the washer pump, the intermittent wipers start running. I'm not sure how the intermittent relay works, but thinking the timer is from charging a capacitor which then "bump starts" the wipers to run a single cycle.

Is there is a reasonably simple way to isolate the pump so it allows the intermittent mechanism to run without activating the washer pump? Could be a fun project. Or should I just go back to the original plan of installing the Car Magic switch? I just like the idea of minimizing the wiring.

[Spoke]

@bbrock

Do you have documentation describing the wiring? I'm not familiar with the kit.

[bbrock]

@bbrock

Do you have documentation describing the wiring? I'm not familiar with the kit.

@Spoke
I'm not actually using the kit. The kit is pretty straightforward. It is a microswitch that replaces the stock plunger valve on the wiper switch and then feeds 12v to the washer pump via a relay. Simple enough, but requires drilling the wiper switch assembly to accommodate the micro switch and running more wire from the microswitch and fuse box to the relay, and relay to the washer. It is simpler and more accessible to do the whole install under the cowl of the car, and I think, more elegant.

Instead of the kit, I'm branching off the brown/black wire that feeds power to the intermittent relay for cars that have them. 12v is fed to that wire whenever the wiper lever is pulled back for manual pulse wipers, or down into the intermittent position. Works great when I pull the lever back for pulse. With the lever down for intermittent, it seems to be bleeding current to ground through the washer motor and screwing up the timer circuit on the intermittent relay. It would be cool if there was a fairly simple circuit that sends current to the pump when the wiper lever is pulled back, but not when the lever is pulled down. I'm pretty good at building circuits, but less so at designing them.

Here is a link to Jeff Bowlsby's doc showing the intermittent circuit and discussion of running a washer pump off it on the last two pages. And below is a pic of the relay I'm using.