Installing a wiper delay unit

[Daverham]

OK kids. I need some help!

I purchased the JC Whitney wiper delay unit and followed the directions carefully, testing inputs and outputs as I go. Everything going swimmingly until the last step. The last step: "If your wipers work, delay and park as they should, you are done and you may cut off the blue wire from the unit.... if they stop in random places (do not park) then you must install the blue wire by connecting it to the park circuit wire, which will be the only wire we have not yet used in your 4-wire wiper system."

I'm paraphrasing here, but that's the idea.

So... I had identified, all within the plug that attaches to the wiper motor:
1. Ground wire to the motor
2. Switched-constant positive to the motor (as in, switched via the key, but constant after that).
3. Low speed positive terminal to the motor
4. High speed positive terminal to the motor
5. And a MYSTERY wire, that I can't figure out what it does. Edit: I have since figured out that this is the "park" wire. It is black with a green stripe.

So, naturally, I figured the mystery wire must be the park wire (edit: that was correct), so I connected the blue wire (from the unit) to that... when I turned on the delay unit, smoke came out of the box! I quickly disconnected and things went back to normal. I think I may have even escaped without frying the delay unit. The relay is still switching as it should.

So... what's that mystery wire and, as a corollary... where is the park wire? I thought the park circuit was all self-contained between the motor and the worm gear drive.


I drew up a little diagram of the plug, showing where the mystery wire is. Edit: that mystery wire has proven to be the "park" wire, and it should be attached to the blue wire in the JCW kit.

Here's the unit:
http://www.jcwhitney.com/windshield-wiper-delay/p2004484.jcwx?filterid=j1

Update:
Here's the complete instructions on JCW (edit: there is a special section in the instructions for VW, but DON'T use that part. DO NOT follow the "VW" directions, just do the "typical" install):
http://www.jcwhitney.com/jcwhitney/sku/documents/InstallationInstructions_561.pdf


And here's the relevant bits (below). After reviewing the diagrams I have two comments:

1. Since the blue wire would connect to the white wire via the relay, and it smoked, the mystery wire is likely connected to ground at some point (although I thought I checked for that) - because the white wire is positive, so that would explain a short and smoke.

2. What on earth are they showing the blue wire connected to in this diagram (bottom schematic)? It's not labeled! Edit: This should be connected to the "park" wire, which is black with green stripe.

EDIT: This schematic, shown at the bottom of the above triple-image is WRONG. See about 12 posts below for the RIGHT way to do it, specifically, they have the green and white wires swapped in this diagram.

[Daverham]

Nothing? Man... Crickets in here!

I've continued my research and found a helpful diagram of the inner workings of the park circuit, posted by Jim Mais (http://www.nls.net/mp/volks/):

This could explain the short, if it really applies to my bus. I double checked this against the Bentley schematic and they seem to match up. Why didn't I just look at Bentley to begin with? Well... I did, but this one is much easier to read. It's BIGGER for one thing, and just much easier to "get" for the armchair electrician. Anyway, how to test that my mystery wire is really the park wire? According to this schematic, if that was true then there would be continuity between the mystery wire and the motor's low speed wire when the wiper switch was in park (off). Tested... verified!

(that's another thing... it's helpful to think of the wiper's OFF position, not as OFF, but as PARK... you're not turning the wipers OFF as much as you're just turning them to the PARK position. They are only really truly OFF when they are in the PARK position AND they are actually parked. Until then (while they are completing one last sweep), they are quite ON.)

So this makes sense, if you look at the relay schematic (way) above, while the relay is open (delaying) it is connecting the wiper's low-speed "hot" wire to the blue (park) wire, which is getting grounded as soon as the wipers park. Short city!

So... why do you think they would ground that? Why not just leave it open while parked? Seems to me if I just disconnect that ground through the park system, everything would work according to plan. I can't see that that ground is really doing anything.


Bah! I know how to attack this... draw the relay circuit into this diagram shown above - then redraw until it's right. Here goes...

[SGKent]

it may load the motor so it acts as a generator and places resistance to the wind trying to move it. It would also cause the motor to stop spinning when the power is off rather than continue from the momentum.

I think I see a dance here where you could intermittently provide power to 53a at the switch and turn the motor speed to whatever speed you want intermittent to work at, then turn the interval timer on. As long as the interval was greater than the time it takes the wipers to return it would work. The downside I see in this is you better buy lots of motors because that park cam switch would be carrying all the load and it may not be built for intermittent operation - meaning turning them on at low speed for 15 minutes then off 10,000 cycles in the life of the bus may not stress the switch, but constantly cycling it for an hour might burn it up.
_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[SGKent]

you might also be able to incorporate a double pole relay where you interupt the park circuit at the same time the power is applied to the motor, then the relay returns to normal and the park circuit takes over to finish the sweep. However again you are relying on the park switch and I don't know if it can stand constant cycling.
_________________
"Most people don't know what they're doing, and a lot of them are really good at it." - George Carlin

[dwill49965]

Daverham - I installed a wiper delay unit on my '78 Westy last year. It works great. I'm at work now, but when I get home, I'll check my wiring.

It is very simple - only two wires to connect into the wiper wiring system.

I hooked mine up the same way you did yours, and the wipers didn't park. Then I had to add the extra "park" wire, and it works perfectly.
_________________
Darryl
--------------
'78 Westy, Boston Bob built 2.0 L, FI, MSD 6A

[Daverham]

Sounds great. If you can figure out where you put that "extra" wire (it's blue on my kit) - that would be helpful. I am looking at these schematics, trying to figure this out, but it may not be 100% representative of what's really going on in the bus - according to a quick test with my meter this morning, I don't see that park circuit grounding anything - so it's kinda hard to engineer a circuit that works if the schematic isn't correct. I'll have to double check, I suppose... but if you have it all figured out already, that would be nice!

Thanks.

[Daverham]

I've made an edit to Jim's schematic. I believe this to be correct. Can anyone verify?

Specifically... the circuits are all THE SAME as Jim's original diagram, but:

1. I am attempting to show the mechanical separation of the switch from the motor - and the span of wires between them - this helps me visualize the wires going from one to another and where certain connections occur, such as...

2. This puts the connection (arbitrarily labeled node X) within the wiper switch. Does anyone know if this is correct? It COULD be in the motor itself, but I think it happens in the switch. Electrically, it would be the same, until you start adding relays in between...

3. I have pulled the ground connection outside of the motor housing outline, which would complete the 5 wires that actually go to the motor terminal/plug.

[dwill49965]

Hi Daverham:

I just looked at my wiring. The "extra" wire on my delay unit is also blue. I tapped this wire into the black/green striped wire (or is it green with a black stripe?) under the steering column. The delay unit then worked correctly. The blk/grn striped wire is the park control circuit.

I also found my instruction booklet. It is actually pretty lengthy and has great descriptions of what is going on, the steps to follow, and example wiring for several makes of vehicles (including VW, but the wiring colors were different than the bus).

Edit: I just clicked on the link to your JCW instructions, and they are the same as the ones I have - only difference in my unit is that a couple of the wire colors are different, but have the same functions.

So, here's how to hook it up (if you haven't done it already - but I think you have).
Step 2: - the wire is blk/grey
Step 3.1 b) low speed wire is black.
Step 3.2 a) high speed wire is blk/yellow

Then follow Steps 5.1 and 5.2. For step 6, attach the blue wire to the blk/green wire, and it should all work.
_________________
Darryl
--------------
'78 Westy, Boston Bob built 2.0 L, FI, MSD 6A

[Daverham]

Thanks for taking the time to look that up - that's exactly how I did it, and I got smoke! I'm going to go double check everything and make sure there isn't just s dumb, accidental mistake in there.

[Daverham]

I'm starting to feel like the rest of the world is crazy...

Dwill, you say you followed the directions and it worked. And the directions say it will work, but looking at the schematic it seems clear to me that the hot park circuit would short to ground when parked and that's exactly what it's doing in my bus. So why does this work for you?

Crazy.

I'm about to just engineer my own wiring scenario. Too bad that ground in the park circuit is soldered directly to the motor chassis. I wish it was a wire I could just unplug.

[Daverham]

I redrew the circuit again, showing the relay in place. Here's the obvious short I'm talking about: When the wiper switch is in the LOW position, the relay is in delay mode (switched to the N.O. side), and the park circuit is in the parked position. ZZZZZZT!

So now what?

It seems like you'd just skip all this parking nonsense, but you need for that park circuit to engage after the relay provides the 1-second impulse to the motor, to complete the sweep of the windshield - that's what' brings 'em home every time, when you're using the relay.

Seriously... what is that dumb ground connection for at 31 (left side)? I'm about to get in there and pry it loose. Just seems kinda strange that they would put a ground in there for nothing.

[dwill49965]

I think I see your problem. In the last figure you posted, your white and green wires should be the other way around. From the instructions, the green wire is connected to the switch side of the (now cut) black wire.

The white wire should be connected to the (now cut) black wire on the wiper motor side.

Your diagram above shows the opposite.
_________________
Darryl
--------------
'78 Westy, Boston Bob built 2.0 L, FI, MSD 6A

[telford dorr]

Personally, I'd wire it this way (reference to first Jim Mais diagram, above):

- remove the green wire from switch 53e to wiper motor 31b.

- connect delay unit white wire (common pole) to switch 53e.
- connect delay unit green wire (NC pole) to wiper motor 31b.
- connect delay unit blue wire (NO pole) to switch or wiper motor 53a.
- connect delay unit red wire (+12) to switch or wiper motor 53a.
- connect delay unit black wire (ground) to ground (wiper motor 31).

Here's the reasoning:

- the delay unit will only operate when the wiper switch is off; conversely, the wiper switch will override the delay unit when in any 'on' position.

- the delay unit will trigger the wiper motor into motion by feeding power into its 'park' circuit; the wiper motor will then re-stop at the park position. There will be no conflict between the delay unit and the stock wiper functionality.

Basically, this wiring method allows the new delay unit to momentarily override the wiper motor park function, causing the wipers to sweep.

p.s. the ground connection to the park switch on the motor (31) is what quickly stops the wiper motor when the blades reach 'park' position. This is because the spinning wiper motor acts like a generator; shorting it dumps the rotational energy. Without this connection, the motor rotational momentum can cause it to coast right through the park position, and keep going.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)

[Daverham]

OK... I figured it was a good idea to let the bad info go away, thus the double post. Anyway, here's the GOOD INFO. Thanks to everyone who helped as I worked through this, especially Dwill, who nailed it. Here's the success story:

I should mention that my bus is a 1978, with 2-speed wipers. That's a steering column switch.


1. Buy one of these from JC Whitney for $20:
http://www.jcwhitney.com/windshield-wiper-delay/p2004484.jcwx

2. Remove your ash tray AND the metal housing that is slides into. This is not only where the unit can go, but it's a handy window to look through while you're messing with wires!

3. Wire it up properly (this is the tricky part. BE CAREFUL how you follow the directions that come with the kit, they are misleading, see below for details.)

4. Put a nice little surround plate around it to make it look nice.



Wiring:
I had a lot of trouble with the wiring because the instructions that come with the kit are ambiguous if not just plain wrong. They tell you how a "typical" installation should go, and then they have a special set of instructions for "most Volkswagens" - well.... IGNORE the VW part, and just do the TYPICAL installation. The VW part is wrong and will short out, resulting in smoke and will fry the delay unit - ask me how I know! Thankfully, I was able to disassemble the unit and replace the burned wire inside.


Shown below is the proper wiring. This is a great schematic, originally drawn for stock wiring by Jim Mais, I have added the JC Whitney relay part...

This is the VW-specific wiring diagram that comes with the kit. This is BAD NEWS. Don't do it like this (the green and white wires are reversed compared to how they should be:

So, you have the wiring all figured out now. Great. But you don't want to bolt that thing to the top of your dash, do you? And I better not hear you drilling any holes! So...

I made this little surround plate at a laser-cutting shop. I'd be happy to share the EPS file for free, or I'd send you a plate for like $8, I guess. I also cut out a backing plate from some steel scrap. That's 5 x 1 inches.

Here's how I pre-assembled the surround and the backing plate, before installing the delay switch box from the back. They are siting there, sorta loose:

After you pop the delay switch box in from the back, tighten the screws, and everything firms up really nice. It's very solid in there, looks good and 100% reversible. Note that I REMOVED the little mounting bracket/pedestal that came with the unit. You won't need that. Anyway, If you wanted to go back to OE... no problem, no drilling, no damage:

Here's the close up:

And the overall impact on the dash:

Oh and it works great!

[dwill49965]

Daverham - The diagram you have stamped as "WRONG" from the original instructions is what worked for my setup.

Anyhow, here are pics of my installation. I still use my ashtray for misc things, so I put mine on top of the Tire Pressure info sticker between the steering wheel and the dash. It fit nicely in there, and all the wiring is a very short distance and easily accessible to where it needs to go under the steering wheel column. The wire bundle easily pulls down, and can be pushed back up out of site.

And, I couldn't resist putting in a pic of the early 80's Canadian Tire packaging.

_________________
Darryl
--------------
'78 Westy, Boston Bob built 2.0 L, FI, MSD 6A

[Daverham]

That's a cool old box, I love that stuff.

To be clear/fair on the "wrong diagram". The kit does come with another instructions and a diagram that looks just like the "wrong" one at a glance - but they green/white wires are reversed. The kit DOES come with the correct instructions, but it ALSO comes with this wrong one... and it happens to say that the wrong one will work for VW's, specifically. It is the only car manufacturer that they call out in an otherwise totally non-specific, universal kit. The problem is that it's NOT the VW setup that works in a VW bus... its the general.

It's a questions of the placement of the green and white wires. The way you described it to me is opposite of this diagram, but it is the same as the other diagram (which I didn't show). They are both in there.

Anyway, it's just worth noting for any future installers to look at this carefully, understand the circuit - what you're hooking where - and make sure that the common terminal of the relay is going to the motor, whatever color the wires are, as I doubt they are perfectly consistent over the years, in this and other kits.

[telford dorr]

[Daverham]

Sorry, that's probably my fault that it appears bogus, but I'm pretty sure that it's not. Mostly it's all about the NC and NO labels in the relay, which stand for normally closed and normally open, respectivley. Closed meaning "on" and open meaning "off" on circuit speak. Forgive me if you know this. That means that when the relay unit is not being used, it is at rest in the NC position, which allows your wipers to park and operate as normal in the low and high speeds.

The diagram shows the relay in open position while the the main switch is turned to off. So you're right, nothing much would be happening here until you switched the main wiper switch on. But it's still wired correctly. It's just not being "used" very smartly in this imaginary scenario. It would be clearer to show the relay in the closed position since the wipers are off and so the relay would likely be turned off too.

If you connected the blue wire to 53a, as you have suggested, you'd be overriding the park mechanism/switch. Keep in mind that the park mechanism is shown here in the parked position, so it is not providing juice to the motor through the relay, but it would usually be connecting positive battery power to the blue wire, through that cam switch.... Until it comes back around to the parked position and stops. I guess this diagram is showing everything positioned in a very inactive state, but it is entirely possible, and wired quite correctly. Simply turn on the wipers and it will be working for you.

And you have to imagine that relay sitting in the NC position any time the relay unit is turned off. That's what NC means. This circuit has many possible states and varibles, it would be best shown as a series of drawings or An animation, with so much going on.

[greenbus pilot]

OMG!!! They still make that thing? I bought one 20 + years ago for my Bus.
Worked darn well, too. I pulled the rheostat out and mounted in the dash, next to the hazard switch or something. Makes a neater install.
Sorry I cannot remember how to wire it, but like I said, 20 + years ago.
It WILL work, though.
Rain-X works well, too. I do not even miss the delay unit today........
_________________
Sent from a white van down the street.

[telford dorr]

OK, after studying the written description of this unit's operation, I find it functions a bit differently than I had expected. When the delay unit is 'off', the delay relay is inactive and power passes directly through it, allowing normal low speed operation. When triggered, it interrupts normal low speed power, instead feeding it from the wiper motor park switch, thus allowing the wipers to complete one cycle and stop (its assumed that they're already in mid-sweep when the relay activates.) The relay is continuously activated for the duration of the delay time. After the delay times out, the relay deactivates, allowing the cycle to repeat. The wiper switch must be on 'low' for the delay unit to function. My assumption is that when set to its minimum delay rate (or 'off'), it allows continuous low speed wiper operation.

It will function correctly as drawn (although showing the delay relay pole in the NC position would make it more clear), with only one problem: make sure the delay unit is 'off' (such that its relay cannot activate) when the wiper switch is in the 'high' speed position, otherwise when the park switch is not in the park position you will feed power into both the low speed brush and the high speed brush of the wiper motor at the same time. Wiper motor won't like it; may blow the fuse. See no fix for this problem.
_________________
'71 panel, now with FI
'Experience' is the ability to recognize a mistake when you're making it again - Franklin P. Jones
In theory, theory works in practice; in practice, it doesn't - William T. Harbaugh
When you're dead, you don't know you're dead. The pain is only felt by others.
Same thing happens when you're stupid. - Philippe Geluck
More VW electrical at http://telforddorr.com/ (available 9am to 9pm PST)