Has anyone here ever added intermittent wipers to their Charger?

[MaximRecoil]

I plan to do this as soon as all the stuff I ordered comes in the mail. Apparently JC Whitney used to sell a premade unit for this (link) for about $15, but it is cheap/plasticky looking. Other companies have made premade units over the years too, and all of them I've seen have been cheap/plasticky looking. Hella makes a unit, but for the hilariously high price of $90.

Going on the assumption that an add-on intermittent wiper device will work with a '69 Charger 2-speed wiper motor (everything I've read seems to indicate that it will, but you never know), I've ordered some parts:

1. Windshield wiper timer module (MXA041)

2. Hammond diecast black aluminum enclosure with flanged lid (1590SFLBK)

3. Kilo International black diamond-knurled aluminum knob with skirt

4. Standard .093" Molex connectors with locking latch (3191 series)

I don't want to drill a knob hole in my dash like this guy did, so that's why it is going in a box. I'll mount it on the underside of the dash below the ignition lock; there are already several screw holes down there made by previous owners, so a few more won't hurt anything (plus my car is a beater anyway). Not having intermittent wipers when it is just misting, drizzling, or lightly raining drives me nuts.

[Dino]

I have the exact same circuit board but have not installed it yet.  I'm also mounting it under the dash. I'm thinking of using one of these for the knob:  http://www.ebay.com/itm/Mopar-66-Coronet-Windshield-Wiper-Switch-Knob-NEW-/170633707059?pt=Vintage_Car_Truck_Parts_Accessories&hash=item27ba8fbe33&vxp=mtr

I got tired as well turning the wipers on and off in a light rain, this is going to be way better.  It's also well made with a solid potentiometer.  I think you'll like it.

[MaximRecoil]

Cool knob, but I doubt it will fit the shaft on the MXA041's pot. The shaft is 6mm, and pretty much no American company was using metric sizes for anything in '66. Also, it is a knurled/splined shaft (coarse splines, like foreign pots tend to have), so you either need a push-on knob that is specifically made for a 6mm coarse-splined shaft, or a knob with a 6mm smooth hole and a set-screw (the knob I bought is the latter).

I chose a small black box and a small black knob because I didn't want it to catch the eye, but rather, kind of blend into the background of my black interior.

I also like that the MXA041 is made from inexpensive off-the-shelf parts, and I could repair it indefinitely if I needed to.

[Dino]

Having it all black will definitely blend in.  I though about doing the same but for one I have a green interior so no blending going on here  , and second I also will have a trunk release button mounted under the dash so that and the wiper switch will look like options. (in my mind anyway)

I bought the knob knowing it would not fit the potentiometer, but since the knob has a set screw I think I can dremel out the back (half moon hole now) and make it fit.  If not, I'll be out a few bucks. 

[MaximRecoil]

Having it all black will definitely blend in.  I though about doing the same but for one I have a green interior so no blending going on here  , and second I also will have a trunk release button mounted under the dash so that and the wiper switch will look like options. (in my mind anyway)

That will probably look pretty good.

I bought the knob knowing it would not fit the potentiometer, but since the knob has a set screw I think I can dremel out the back (half moon hole now) and make it fit.  If not, I'll be out a few bucks.

The circular part of that D-shaft hole is probably ¼", which is a little bigger than 6mm (6.35mm), and if so, once you Dremel it out to be fully circular, the knob will have an eccentric feel as you turn it because of it being slightly off-axis. A common solution to that problem is to wrap a little tape on the pot's shaft so that the knob is centered when installed. Also, because it is a split shaft, make sure your set screw is positioned so that it tightens into the edge of that split, like so - link. If you don't, the set screw will compress the shaft, and it won't stay tight.

The only problem is (and it is only a cosmetic problem): the "wiper" text on your knob won't be horizontal when you position the set screw to either of the two correct locations, except by pure luck. You could press-fit something solid down into that split in the pot's shaft so that you could position the set screw wherever you want without compressing it though.

I'd like to see a picture when you get it done.

[Dino]

Thanks for the tips!   

I thought about the lettering and would like it to be level when the switch is off obviously.  If the set screw and the split don't line up, I may just try to drill a dimple in the knurled part to accept the set screw.  I'll be sure to post pics.

[JB400]

http://www.protouringmopar.com/showthread.php?1237-intermittent-wipers

[A383Wing]

I got intermittent wipers on the 66 (variable speed) and the Daytona (2 speed)

[b5blue]

Interesting! 

[Dino]

Would anyone happen to know which wires to tap into on the switch?

[MaximRecoil]

Would anyone happen to know which wires to tap into on the switch?

I don't know yet (I guess my MXA041 is on a slow boat from China), but I plan to use a multimeter to determine which two of the windshield wiper switch terminals are shorted (i.e., which two terminals have electrical continuity between them) when the switch is in the low speed position. The wires connected to those two terminals will be the wires to tap into.

This thread here - link - has a lot of details. He posted a picture on that thread showing all the connections too:

[Dino]

Thanks!  That'll do the job.

I got my switch knob today.  I used a small file to round the flat spot in the hole until it was big enough to get a drill bit in there.  It was very easy to get a nice round hole in the soft metal.  The knurled shaft is tight in the switch knob and the set screw grips very tightly on the shaft.

I need a smaller housing box than what I have though to mount it where I want under the dash.

[MaximRecoil]

That looks awesome.

Finding the perfect size box is such a pain. The one I got is a little bigger than I wanted, but it will still fit where I intend to mount it. Since it is wider than it needs to be, I intend to mount the MXA041 to the left rather than in the center, and that will leave room on the right side of the box for something in the future, like maybe a Dixie horn button if I ever get around to that project.

By the way, what does it say on that little 8-legged socketed chip? I figure that's the key part of the timing circuitry, and I'm wondering if it is an off-the-shelf part.

[Dino]

My box is too big as well.  I could turn it sideways but it's too deep and the holes for the circuit board are not lining up with anything.  I may just build one.

Here's the chip

[MaximRecoil]

Nice. It is a timer chip, 16 cents.

Everything else on that board is also off-the-shelf and cheap (the pot is probably the most expensive part), which is good, because it could be repaired indefinitely if needed.

As for the mounting holes in the circuit board, the easiest thing to do is drill matching holes in the bottom of the box, and use long screws, nylon spacers, and nuts to secure it in the box. Here is an example of that common type of PCB mounting:



That's a small CR2032 battery holder PCB that I designed and had manufactured as a replacement for the original 3 × AA battery holder, and it is mounted to pre-existing holes in the larger PCB below it. In the case of mounting in a box, for appearance reasons you'd probably want to countersink the holes you drill in it and use flathead screws so they sit flush; then the nuts will be concealed inside the box.

[MaximRecoil]

By the way, if you follow the wiring in that picture, I suggest ditching the jumper and hooking up the COM and NO wires to the high circuit of the factory switch, rather than the low; that's what worked for me anyway. There is also a wiring diagram that comes with the MXA041, which also has the jumper but is otherwise different than that picture. I don't know whether that wiring method works or not.

I'm not sure what the intended method of operation is. The way I have mine hooked up is like if you wired a second on-off switch in parallel with the factory switch (high position). To get intermittent function, you turn on this MXA041 gizmo, leaving the factory wiper switch off. To get normal low and high speed operation, you leave this gizmo off and use the factory wiper switch as you normally would.

If for whatever reason you turn on the factory wiper switch while the MXA041 is on, there is no benefit, but nothing bad happens either. With the factory switch on high, the MXA041's relay continues to click away at whatever interval it is set to, but it is "ignored", because it is on the exact same circuit. With the factory switch on low, every time the MXA041's relay clicks on the wipers speed up to high, and then go back to low a ~second later when the relay turns off, and so on. I tested that out just to make sure I wouldn't get a smoke show if both the MXA041 and the factory wiper switch were on at the same time.

Maybe the wiring diagram that comes with it (link), if it works at all, results in a different method of operation (i.e., a different relationship between the MXA041 and the factory switch), but I don't know because I didn't try it, and the method of operation I have now is perfectly fine anyway. Raining hard? Use the factory switch. Barely raining? Use the MXA041. Accidentally have them both on at the same time? Nothing bad happens.

[MaximRecoil]

I've got it all installed in the box; I'll mount it under the dash tomorrow:







I like that knob, but it is kind of small relative to the size of the box (1/2" diameter with 3/4" skirt, the box is 1-11/16" tall), so I ordered a larger version of the same knob (3/4" diameter with 1" skirt).

[Dino]

That looks really good but I agree that the other knob will look better.

I had not thought of wiring this the way you did.  That's pretty nifty.  I don't want the wiper to speed up on interval pulses though so I'm going to have to wire it a bit different.  The stock wiring places it in the low circuit.  When I need intermittent wipers I need the stock switch on low and the gizmo on.  Then I can either turn off both or leave the gizmo on for next time.  Either way works.

I need to go looking for another box so I can mount mine as well.

[MaximRecoil]

That looks really good but I agree that the other knob will look better.

I had not thought of wiring this the way you did.  That's pretty nifty.  I don't want the wiper to speed up on interval pulses though so I'm going to have to wire it a bit different.  The stock wiring places it in the low circuit.  When I need intermittent wipers I need the stock switch on low and the gizmo on.  Then I can either turn off both or leave the gizmo on for next time.  Either way works.

I need to go looking for another box so I can mount mine as well.

I don't know how to access the low wiring switch correctly I guess, because I hooked it up to the two terminal tabs on the switch that showed continuity when the switch was in the low position first, but things got hot quickly. Then I just hooked up two wires with alligator clips to those same two terminal tabs and shorted them together. It made the wipers come on in low speed mode, but the wires I was holding together in my fingers got hot in a matter of seconds, hot enough to burn my fingers if I'd kept ahold of it. That didn't make any sense to me at all, but when I tried the same thing on the two high speed terminal tabs, the wipers came on in high speed mode, and the wires stayed cool. Then I thought about how intermittent wipers work in modern vehicles that have them from the factory, and I believe it is usually the high speed mode that is activated. Since it is only going to be one wipe at a time, and then a delay, might as well get that one wipe done quickly instead of slowly.

But if you access the low speed circuit correctly, I'd be interested in the details, because my experience with it was just bizarre.

If you hook it up like in the photo I posted from that forum thread, it won't work like you are describing; it will work like mine work, because I hooked it up exactly like he did, except I eliminated the jumper (having that jumper in place fried a trace on the gizmo, which I had to repair). I believe the jumper should only be there if you follow the factory wiring diagram. He didn't follow the factory wiring diagram, but he left the jumper in place, and for whatever reason it didn't cause a problem in his particular installation.

The factory diagram appears to reroute the factory switch circuit through the normally closed (NC) circuit of the relay on the gizmo, which allows the factory switch to work normally when the gizmo is off. When the gizmo is turned on, the NC circuit of the relay opens (thus cutting power from the factory switch) and the normally open (NO) circuit closes, thus directing power to the gizmo at the same time that power is cut from the factory switch (and vice versa when you turn the gizmo off).

[MaximRecoil]

I scanned in the wiring diagram that came with my gizmo so it is easier to read than the tiny ones posted online:



And here is an even larger version if needed - link.

I'm no expert in reading wiring diagrams ... is that connected to the high speed circuit or the low?

I think that our cars' wiper motors are common positive, though I don't know for sure. If Pete in NH sees this, maybe he can give some insight on this, i.e., which of those two diagrams is correct for our cars (if either), and how it is supposed to operate when wired according to that diagram.

[Pete in NH]

I looked through the FSM it is not clear at all on the wiper system wiring as far as the dash board switch functions. My best guess is that it is a common negative system. Are you dealing with a two speed wiper motor or variable speed? The two speed motor is a permanent magnet field motor. A resistor feeds a low speed brush and the wiper switch feeds a high speed brush directly for the higher speed. The 3 speed and variable speed motors have an actual field winding in the motor.

I really couldn't follow the wiring diagram provided with the circuit board in relation to the Chrysler two speed motor let alone if you have a 3 speed or variable speed motor.

[MaximRecoil]

I looked through the FSM it is not clear at all on the wiper system wiring as far as the dash board switch functions.

I had the same problem when I looked in the FSM. But like I said, I'm not great with wiring diagrams / schematics, so I thought maybe it was just me. Good to know it wasn't.

My best guess is that it is a common negative system.

The reason I suspected it is a common positive system is because at the plug for the factory switch, there is only one terminal that is on 12v acc. (3 terminals actually, but they are all in parallel with each other, i.e., they all have continuity among each other, and one of them isn't used, i.e., it doesn't have a corresponding terminal tab on the back of the switch). Then there are two terminals, at least one of which has continuity with ground (it seems like they both should have continuity with ground, but I don't remember if I checked; plus it doesn't make sense that they would both have continuity with ground, because that would effectively make them the same terminal tab; but then I don't really understand how a common positive system can work in a car which is inherently based on common ground), that activate the wipers when shorted with the positive terminal, one activates low speed (but that quickly heats up the wire I used for shorting [I have no idea why], as I described in an earlier post), and the other activates the high speed when shorted with the positive (no heat in the wire I used for shorting, so that's the circuit I tapped into with the gizmo).

I made a diagram:



I currently have my gizmo wired to the high speed circuit (terminal 5 goes to the COM terminal of the gizmo, and terminal 1 goes to the NO terminal). The gizmo is just functioning as a separate switch; no integrated function with the factory switch at all (albeit in parallel with the high speed circuit of the factory switch), which is the simplest way to hook it up.

Are you dealing with a two speed wiper motor or variable speed? The two speed motor is a permanent magnet field motor. A resistor feeds a low speed brush and the wiper switch feeds a high speed brush directly for the higher speed. The 3 speed and variable speed motors have an actual field winding in the motor.

2-speed, low and high (3 position rocker switch: off, low, high). I've read that the MXA041 is only intended to work with 2-speed wiper motors.

I really couldn't follow the wiring diagram provided with the circuit board in relation to the Chrysler two speed motor let alone if you have a 3 speed or variable speed motor.

That wiring diagram doesn't make much sense to me either, but again, I wasn't sure if that was just me.

That looks really good but I agree that the other knob will look better.

Here it is with the bigger knob:



Not only does it look better, but the increased leverage of its larger diameter makes the pot turn easier, and because it has a bigger cutout in the underside of its skirt, it can slide all the way on (because that cutout in the base of the skirt is big enough to clear the pot's retaining nut; the smaller knob bumped into the retaining nut before it could slide all the way onto the pot shaft), and when it is slid all the way on, it sits down nice and close to the front face of the box, as if it was designed specifically to be there.

[b5blue]

Got a link to that bigger knob? 

[MaximRecoil]

Got a link to that bigger knob?  

Kilo International OESL-75-4-7 KNOB BLK/MATTE .75" DIA 6MM SHAFT

If you order it from Digi-Key (I order from them all the time; their shipping rates are usually cheaper than Mouser's), select "U.S. Postal Service First Class Mail* (next day shipment)", and it is about $3 ($2.86 to ship to my location), and it got to me in 2 days.

Here's a video of the gizmo in operation:

http://youtu.be/k3O0twcFO2M

The wipers come on for the initial wipe immediately when you turn on the switch; I just didn't get the camera up to the window fast enough to see it. First I showed it at its fastest setting, ~3 seconds delay, and then I turned it up a bit to ~8 seconds delay. It will go as high as ~30 seconds delay.

[Dino]

Bringing this one back!

Is this how it goes? Just making sure I'm looking at it right. And ommit the jumper?

[MaximRecoil]

Bringing this one back!

Is this how it goes? Just making sure I'm looking at it right. And ommit the jumper?

The arrows in your picture are pointing to terminals on the headlight switch, so that won't work.

I read through this thread to refresh my memory of what I did in 2014, and in post #21 I posted a diagram of the windshield wiper switch terminals, and beneath the diagram I said:

"I currently have my gizmo wired to the high speed circuit (terminal 5 goes to the COM terminal of the gizmo, and terminal 1 goes to the NO terminal)."

And yes, I see that I mentioned a few times in this thread that I removed the jumper because leaving the jumper in place fried a trace that I had to fix.

[b5blue]

I used this from "Hella". https://shop.sohiperformance.com/product/hella-control-unit-wash-wipe-int-12v-