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.

[lesorubcheek]

It's kinda difficult looking at the wiring diagrams alone to tell exactly what's making continuity when the lever is pulled. Makes sense because there's no electrical connection normally associated with a 914 when pulling back on the lever, except maybe with the intermittent feature. Mr. Bowlby does say in the article he's only heard using the S1 to S brown and black wire may work, so it may well be the parallel load added with the pump is causing the normal operation of the intermittent wipers to fail, yet it does work as expected for pulling back to get a quick squirt.
This is just a guess, but if you look at a 911 diagram for actuating the pump, it uses connector 53c off the wiper switch. I don't have access to a 914 switch and wiring right now, but the 914's diagram does show a 53c off it's switch, just not connected to anything. If, and it's a big if, 53c actually has a pass through wire, it may be worth trying for the pump connection. That way it wouldn't interfere with the normal intermittent function when in the down position. If there's no wire coming off of 53c, then it may be too much trouble to even think about fooling with it, but if there's a wire, I'd get a meter and see if it gets 12V when the lever is pulled. If so, it'd just require extending a wire to reach the pump. Again, just an idea, and it may well all be a wild goose chase, but it's an intriguing problem.
Best of luck,
Dan

[bbrock]

It's kinda difficult looking at the wiring diagrams alone to tell exactly what's making continuity when the lever is pulled. Makes sense because there's no electrical connection normally associated with a 914 when pulling back on the lever, except maybe with the intermittent feature. Mr. Bowlby does say in the article he's only heard using the S1 to S brown and black wire may work, so it may well be the parallel load added with the pump is causing the normal operation of the intermittent wipers to fail, yet it does work as expected for pulling back to get a quick squirt.
This is just a guess, but if you look at a 911 diagram for actuating the pump, it uses connector 53c off the wiper switch. I don't have access to a 914 switch and wiring right now, but the 914's diagram does show a 53c off it's switch, just not connected to anything. If, and it's a big if, 53c actually has a pass through wire, it may be worth trying for the pump connection. That way it wouldn't interfere with the normal intermittent function when in the down position. If there's no wire coming off of 53c, then it may be too much trouble to even think about fooling with it, but if there's a wire, I'd get a meter and see if it gets 12V when the lever is pulled. If so, it'd just require extending a wire to reach the pump. Again, just an idea, and it may well all be a wild goose chase, but it's an intriguing problem.
Best of luck,
Dan

All good thoughts and I was thinking along a similar path. I need to spend some quality time with the wiring diagram to understand how it works and if there are other options for tapping 12v for the pump. It's curious to me that there is a different behavior pulling the lever back vs. down given that both are sending 12v through the same wire. I'll take a look at 53c to see if that provides an option too. So close that now I feel like I HAVE to crack this nut. (IMG:style_emoticons/default/laugh.gif)