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.

[Superhawk996]

I apologize I'm worthless for this thread. All my books, schematics and parts are packed up and are not at hand to analyze or test.

Looks like you're getting closer to solving this.

Hope this doesn't end up needing an Arduino! (IMG:style_emoticons/default/happy11.gif)

[bbrock]

I apologize I'm worthless for this thread. All my books, schematics and parts are packed up and are not at hand to analyze or test.

Looks like you're getting closer to solving this.

Hope this doesn't end up needing an Arduino! (IMG:style_emoticons/default/happy11.gif)

Ha ha. Funny because I think doing this via arduino would be fairly simple, but overkill.

[Superhawk996]

I apologize I'm worthless for this thread. All my books, schematics and parts are packed up and are not at hand to analyze or test.

Looks like you're getting closer to solving this.

Hope this doesn't end up needing an Arduino! (IMG:style_emoticons/default/happy11.gif)

Ha ha. Funny because I think doing this via arduino would be fairly simple, but overkill.

Can you post a more comprehensive circuit diagram of how you have this wired and what you believe the circuits to be?

I'm wondering if you can utilize the standard Bosch relay with one normally open contact and one normally closed contact to do what you want. I'm thinking you probably need two relays cascaded and/or may need a diode on one of them to prevent the ground from reaching the intermittent relay when one of the relays are activated.

Sometimes when I'm forced to draw the circuit, I'll either realize that I don't understand it as I thought I did from the schematic, or the solution becomes obvious.

[bbrock]

Can you post a more comprehensive circuit diagram of how you have this wired and what you believe the circuits to be?

I'm wondering if you can utilize the standard Bosch relay with one normally open contact and one normally closed contact to do what you want. I'm thinking you probably need two relays cascaded and/or may need a diode on one of them to prevent the ground from reaching the intermittent relay when one of the relays are activated.

Sometimes when I'm forced to draw the circuit, I'll either realize that I don't understand it as I thought I did from the schematic, or the solution becomes obvious.

The circuit is so simple there is really no need for a diagram. See the pic in my first post of the 3-way connector? One of those wires in is the original brown/blk (S1) wire from the circuit that is supposed to go into the relay socket. One wire coming out now goes to the relay socket to complete the original circuit. The other wire coming out goes to the (+) on the washer pump. The washer pump is grounded to chassis through its mounting screw. That's it and the simplicity is why I want to make this work.

Quite simply, I need a switch on the wire between the 3-way and pump that is closed when there is 12v on that wire, and open the rest of the time. Digging around, it looks like I need a low voltage disconnect. Thinking something like this might work. Wonder if anyone with more electronic smarts could confirm.

Now that I know leaving the washer pump connected isn't going to fry the intermittent circuit, I'm leaving it connected for now as I need the washer pump more than the intermittent. I'm optimistic this one-wire, no switch modification solution could work. (IMG:style_emoticons/default/beerchug.gif)

[Superhawk996]

The circuit is so simple there is really no need for a diagram.

I'm not buying that. If it were that simple, it would be working as you thought it would and as Jeff speculated. (IMG:style_emoticons/default/unsure.gif)

I looked at Jeff's write up, your posts etc. With all the piecemeal figures, and diagrams without labeling of how the circuits are wired, fed power, and ground, it just doesn't click for me. It's just the way I was trained by USAF. I need a schematic to understand the big picture and to rule out unintended ground paths. We'll call it a personal flaw. (IMG:style_emoticons/default/happy11.gif)

[bbrock]

The circuit is so simple there is really no need for a diagram.

I'm not buying that. If it were that simple, it would be working as you thought it would and as Jeff speculated. (IMG:style_emoticons/default/unsure.gif)

I looked at Jeff's write up, your posts etc. With all the piecemeal figures, and diagrams without labeling of how the circuits are wired, fed power, and ground, it just doesn't click for me. It's just the way I was trained by USAF. I need a schematic to understand the big picture and to rule out unintended ground paths. We'll call it a personal flaw. (IMG:style_emoticons/default/happy11.gif)

No, it's simple. You are trying to over complicate it (IMG:style_emoticons/default/happy11.gif) . Note that Jeff said "he was told" this would work and Sir Andy said you could take power from that wire for the washer, but did not go that route himself. I might be the first one stubborn enough to try it.

However, they are both right... sort of. If you DON'T have intermittent wipers, you can just take power off the brown/black wire for the washer pump. Pull back on the lever and the pump will run, but you won't get the few cycles of wiper unless unless you have an intermittent harness and relay installed. If those ARE installed, you get a few cycles of wiper when the washer pump runs just like we want. But now there is a problem because that brown/black wire is supposed to be connected to ground in all wiper lever positions other than down ("J"). The ground defeats the intermittent circuit so it doesn't run when the lever is in "off," "low speed," or "high speed" position. Pulling down to J disconnects the brown/black from everything, making it a dead wire. That lets the intermittent run on low speed by energizing the 53. The problem being that hooking the brown/black wire to the pump creates a new path to ground so it doesn't become a dead wire when the lever is pulled down to "J" position. Thus, the intermittent circuit remains defeated.

Important to remember that the brown/black wire was never intended to run a washer pump by the factory. It just happens to be a handy source for 12v when the washer lever is pulled back on the stalk.

I've added the full circuit diagram below, but the only things not shown in the snippet above are what the various switch wires attach to. Those are:

S1 - attaches to 15 on intermittent relay (or taped up and dead end if that option isn't present).
53 - goes to low speed power input on wiper motor
53b - high speed power on wiper motor
53c - not present but apparently where the factory ran power for an electric washer pump on other models. I'm guessing on sixes too.

And if the intermittent option is installed, there is an additional harness that connects the relay to the wiper motor and brown/black wire which is shown in Jeff's article.

The bottom line is that connecting the brown/black wire to anything that creates a path to ground F's up the intermittent circuit as it was designed by the factory. That needs to be an open, dead end wire when the lever is pulled down into the "J"/intermittent position.