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.

[bbrock]

I went ahead and ordered one of these low voltage disconnect modules. There are DIY circuits available, but just to source parts would cost 3X as much and not be as compact.


https://www.amazon.com/gp/product/B07RS49D6...5LSJQ&psc=1

This will be installed between the washer pump and 3-way connector with wiring as follows:

B+ -> brwn/blk wire from 3-way
B- -> chassis ground at washer pump
Out + -> + on washer pump (I will change this wire to rd/blk to reflect it is now a switched power wire)

This SHOULD leave the relay contacts open when the wiper switch is pulled down into the "J" intermittent position and break the path from the brwn/blk wire to ground. When the lever is pulled back for washer, it should energized the circuit on the module which will sense voltage above the cut on threshold and close the relay contacts allowing 12v to flow to the pump.

It should be here later this week and I'll report how it works. (IMG:style_emoticons/default/beerchug.gif)

[Superhawk996]

I went ahead and ordered one of these low voltage disconnect modules.

More stuff for the "simple" schematic to reflect. (IMG:style_emoticons/default/av-943.gif)

I still can't picture it. (IMG:style_emoticons/default/wacko.gif) I stared (sideways (IMG:style_emoticons/default/laugh.gif) ) at the column switch schematic you sent for a while and I'm still not convinced I understand how that column switch is wired and/or where the power is coming from to the intermittent relay when you put it in the J position.

I am almost tempted to go find the box that has my manuals and schematics and dig them out. Like you, now that there is a mystery to be solved, I'd love to solve it. However, there is so much yet to be packed, I'm not going backward to dig out reference materials. I trust that you have a plan. (IMG:style_emoticons/default/shades.gif)

[bbrock]

I went ahead and ordered one of these low voltage disconnect modules.

More stuff for the "simple" schematic to reflect. (IMG:style_emoticons/default/av-943.gif)

I still can't picture it. (IMG:style_emoticons/default/wacko.gif) I stared (sideways (IMG:style_emoticons/default/laugh.gif) ) at the column switch schematic you sent for a while and I'm still not convinced I understand how that column switch is wired and/or where the power is coming from to the intermittent relay when you put it in the J position.

I am almost tempted to go find the box that has my manuals and schematics and dig them out. Like you, now that there is a mystery to be solved, I'd love to solve it. However, there is so much yet to be packed, I'm not going backward to dig out reference materials. I trust that you have a plan. (IMG:style_emoticons/default/shades.gif)

Power for the intermittent comes from 53 (low speed input to motor). If you mentally move the contact diagrams above 53 and directly bellow 53a through the various positions, you can see 53 is connected to 53a (from the starter switch) on the left contact in switch positions J & 0, and is connected through that left contact in position 1, then disconnected in position 2. Why it is connected to power in position 0 is a bit of a mystery to me, as is what 53e is doing. I'm not even sure what it is connected to at 31b.

Isolating the problem by just looking at the part of the circuit modified by adding the washer pump, the pump works fine when connected to S1 (brwn/blk) but the intermittent function does not. Disconnect the pump to break the pathway to ground and the intermittent function works again. Simply, the S1 wire needs to connect to the washer pump when voltage is applied, and be disconnected when it is not.

Here, I added the "complicated" part for you. (IMG:style_emoticons/default/biggrin.gif)

[Superhawk996]

Here, I added the "complicated" part for you. (IMG:style_emoticons/default/biggrin.gif)

You dick (IMG:style_emoticons/default/lol-2.gif) and I use that as your usual badge of honor. (IMG:style_emoticons/default/av-943.gif)



Your comment: "Power for the intermittent comes from 53 (low speed input to motor). If you mentally move the contact diagrams above 53 and directly bellow 53a through the various positions, you can see 53 is connected to 53a (from the starter switch) on the left contact in switch positions J & 0, and is connected through that left contact in position 1, then disconnected in position 2. Why it is connected to power in position 0 is a bit of a mystery to me, as is what 53e is doing. I'm not even sure what it is connected to at 31b. "


That green and white wire isn't always power. When the wipers are turned off, it is connected to ground and acts as an inertia brake by putting ground to the armature. it's actual condition (power or ground) depends on the position of the rotary switch that is connected to the wiper motor shaft.

As for position J -- the only thing that is ever connected when in position J, is the green and white (53e) to 53. (per comment below - Green/White is the inertia brake)

In low speed, the actual 12V power feed is coming through 53a to the set of contacts that also feed 53b when in the 2nd position. Note in the 1st position 53a feeds feeds 53. In the second position (high) then it feeds 53b.

What is on the green and white wire (power or ground) is dependent on the position of the 3 track rotary switch that is attached to the motor armature.


When the motor is parked, I think the green and white will actually have ground on it . . . but I'm not 100% sure and would want to measure this. When the switch is moved to position #1, that ground is interrupted and the 12v power comes over from that other set of contacts fed from 53a to 53.

This is why I need the schematic of where (and how - by pin#) your intermittent relay and washer were installed relative to this circuit. It really isn't a simple circuit.

I could be wrong, but I think the green and white wire (i.e. the inertia brake) is what grounding your intermittent wiper relay? Obviously I'm not 100% sure.