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.

[dr914@autoatlanta.com]

intermittent is activated by pulling the stalk down one below off, washer is activated by pulling the stalk towards you

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.

[FlacaProductions]

As George says - but do you have the tab broken out that allows the wiper lever to actually, physically move down below the OFF position?

[bbrock]

Let's back up a bit. My intermittent wipers work perfectly fine. They work exactly as they are supposed to until I try to power my NEW electric washer pump from the brown/black wire on the main chassis harness that feeds power to the intermittent relay. When I connect the washer pump, the washer works like a champ when I pull the lever on the stalk towards me, but the intermittent does not work pulling the lever down. This is not the factory configuration but would make for an easier, cheaper, and more elegant conversion to electric washers if I can make the whole system work.

BTW - I love the absurd stupidity of the tire operated washer system and really tried to get mine working again. All of the washer valves that fit into the wiper switch assembly I have are either seized up or leak. That includes a new aftermarket one I bought from CIP which is a steaming pile of (IMG:style_emoticons/default/stromberg.gif) . So... reluctantly I am converting to electric and being quite picky about how I do it as usual. (IMG:style_emoticons/default/biggrin.gif)

[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)

[lesorubcheek]

I know the feeling. You just can't let this go without solving it. From the diagram, you can see a connection from a contact on the pull circuit (right 2 contacts) to the input of S1, so you can visualize that just pulling back on the lever will energize the intermittent action, just as 53c should be energized when pulling back on the stalk.


The part I can't visualize from the diagram is what's going on at S1 when the stalk is down or in the J position. It doesn't look like it's connecting to anything if you rock the angle up or clockwise one tick in the diagram. It looks like 53e will connect with 53, just as in the off position, which makes sense as that would connect the output from the intermittent relay to the low speed wiper. I'd expect 53a which is the 12V input to the switch to be connected with S1 when the switch is in the J position..... maybe it is, it just doesn't look clear in the diagram.
Dan

[Spoke]

@bbrock

I'm not sure how pulling back on the stalk energizes the washer as that function was originally a pressure hose going to the tank and tire. On my '74 I replaced that valve with a microswitch and ran a wire to the washer motor. I had to click the stalk down to get the wiper to run.

[bbrock]

@bbrock

I'm not sure how pulling back on the stalk energizes the washer as that function was originally a pressure hose going to the tank and tire. On my '74 I replaced that valve with a microswitch and ran a wire to the washer motor. I had to click the stalk down to get the wiper to run.

Yes, but the trick is that pulling back on the stalk energizes the brown/black S1 wire to run the wipers for two cycles (Sir Andy says it does 4 in his post, but mine does 2). So splitting off the S1 intermittent wire gives you 12v to send to the washer pump when the lever is pulled back. That part works and it pretty darn slick. But when I pull the lever down, I no longer get intermittent action. If you have intermittent on your 74, I'm not sure why the wiper isn't running when you pull back on the lever (IMG:style_emoticons/default/confused24.gif)

[bbrock]

I know the feeling. You just can't let this go without solving it. From the diagram, you can see a connection from a contact on the pull circuit (right 2 contacts) to the input of S1, so you can visualize that just pulling back on the lever will energize the intermittent action, just as 53c should be energized when pulling back on the stalk.


The part I can't visualize from the diagram is what's going on at S1 when the stalk is down or in the J position. It doesn't look like it's connecting to anything if you rock the angle up or clockwise one tick in the diagram. It looks like 53e will connect with 53, just as in the off position, which makes sense as that would connect the output from the intermittent relay to the low speed wiper. I'd expect 53a which is the 12V input to the switch to be connected with S1 when the switch is in the J position..... maybe it is, it just doesn't look clear in the diagram.
Dan

Here is a better pic of the switch circuit. [Bad info]: Looks like the J position connects S1 and 53a and any other position sends it to ground except when the lever is pulled back if I'm reading this right. My DMM tells me with the lever in position J, I'm getting 12v at the relay end of S1 and 0v in the off position so that agrees. Actually I'm reading 11v because I have a low battery due to a busted alternator I replaced tonight. I'll get the battery fully charged and see what it reads.

[bbrock]

My previous post was incorrect. It was dark in the garage when I tested voltage on S1 last night and I failed to notice I was reading mV rather than V. Looking at the circuit diagram again, it looks like S1 is not connected to anything in the J position, and connects to ground in any other position. This is apparently how the intermittent circuit is disabled because if I disconnect S1 (brown/black) wire from the intermittent relay, the intermittent wipers run with switch in the J position, and continue to run in the off position. It also explains why the wire is brown/black which confused me since brown is ground on these cars and brown/white is switched ground. Brown/black might mean it is both a switched ground and switched voltage?

When the lever is pulled back, with the switch in the 0 position, S1 is connected to 53a which is the 12v supply. It's hard for me to tell from the diagram, but I assume S1 is also disconnected from ground at the same time since it would create a dead short otherwise.

This is all starting to make sense now. When the washer pump is connected to S1, it gets 12v when the lever is pulled back and works fine. But when the lever is pulled down into the J position, the washer motor creates a path to ground which prevents the intermittent washers from activating. It seems what is needed is some kind of relay switch circuit so that the path on the S1 (brown/black) where to the washer pump remains open except when there is 12v present. Any ideas on what that circuit should be?

[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)

[Bartlett 914]

It has been awhile since I worked with the washer circuit. I do remember that the intermittent relay timing circuit gets fouled when installing a washer pump. It had to do with the resistance of the coil in the washer relay. The solution I did was to make a high impedance circuit that would then pull the relay for the washer pump.

[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.