Wiper relay and headlight hi/low beam control

[jeffc280sl]

My car has a wiper relay mounted on the driver fender well near the master cylinder.  Wipers were on the other day and they would not shut off using the stalk switch.  Fast and slow speed control functioned but I could not turn the wiper off.  As a temp fix I disconnected this relay.  I took the relay apart today to clean it, etc.  It happens to be an interesting relay, atleast to me anyway.  It is a momentary switch relay. I cleaned the relay and I'm good to go as far as the wipers go.  

Some may remember I'm also working on a plan to use a momentary switch relay and the flash switch on the turn signal stalk to switch between hign and low beam headlights.   Turns out this wiper relay would do the job.  The wiper on/off switch on the turn signal stalk is a momentary switch.  One push on and a second push off.  

That's what I want for the headlights.  Refer to a 280SL wiring diagram.  One of the pins (56a) on the wiper relay is unused.  One could wire the high beams to 56a and the low beams up 56b.  Fused power would be provided to pin 56 after and via the headlight switch. Pin 85 is ground. The flash switch needs to be wired to pin 86.  Here's how I see it working.  Turn on the headlight switch.  Hibeams or low beams would come on.  Pull the signal stalk forward and the momentary switch will provide voltage to pin 86 and cause  fused power (from the headlight switch) to toggle from 56a hi and 56b low beam or the other way around (depends on the last state of the relay.  Pull the stalk forward again and the reverse occurs.  Anyway I have ordered a relay from a VW for this purpose.  If one wanted to stay stock they could use a second wiper relay to do the job.  A note of caution.  The contacts on the 56a side of the relay are physically smaller than the 56b side. I don't know if this would contribute to premature wear of the contact.

Like I said it was interesting to me.  May also be interesting to others.
 
I hope to be able to wire it so that the flash function operates when the headlights are off.  Need to think some more about that.

Jeff C.
1970 280SL 4-speed

[A Dalton]

I have not looked in the relay, but if you are saying that the sw toggles back and forth [ which I think you do] each time the coil is energized , [86/gnd] , then that would be a mechanical latch system .
 If so , that  works and one could use this relay for latching the momentary sig form the stalk and feed the coil side of a power relay for the lighting Load .
 Let me know when you get that VW one , would ya??

[jeffc280sl]

Arthur,

Your right!  The relay is a latching type that accepts a momentary switch input to change latch states.  The VW relay is on the way.  I'll advise.

Jeff C.
1970 280SL 4-speed

[A Dalton]

OK

 I just went on a search and found that Jag uses the same mechanical latch design... I also found some transistor ones for $7 that looked preyty cool..
I like the idea of the mechanical ones .. They showed the interior of the toggle system on the Jag page.. simple enough..

[jeffc280sl]

Arthur,

I took a picture of the relay.  I've got an old email address for you and I'll send it there.  I can't post pics on this site for some reason.

Jeff

Jeff C.
1970 280SL 4-speed

[A Dalton]

Same addy
 Thanks

 While I was surffing for latch relays , I was suprised to come upon a site that used an  ISO/cube relay to jumper the Ballast on ignition for 12v. start .  Kinda cool ..Contacts just shunt R and coil sol. feed can be grabbed right there at  rack sol feed .  That gives you 12v start position only, regardless of temp and no fear of coil feedback to any circuits b/c you now have circuit isolation.[ instead of diode ]
 Foe those without a starter extra sol terminal to grab....

[jeffc280sl]

Arthur,

The VW relay arrived today.  It should do the trick just fine.  A bit of a glich however.  The VW relay is looking for a ground input from the turn signal stalk. All other pins on this relay are either + in or + out.  If I read the wiring diagram correctly, the 280SL stalk provides a + momentary contact. In order to make this relay work in our application I will need a second Bosch relay which will take the + output from the stalk and give a - output to the VW relay. I plan to mock it up tomorrow and test it.

Jeff

Jeff C.
1970 280SL 4-speed

[A Dalton]

Bummer ..
 That is a switched ground circuit like they use on  some horn rings/buttons..

 I am going to try one of the Electronic ones ...

[Naj ✝︎]

Hi, Jeff,

 

quote:I plan to mock it up tomorrow and test it.

How did your test go?

I found a similar 'latching change-over' relay yesterday.
I want to try your experiment. Funnily enough, three terminals are numbered 56, 56a and 56b. The two switching solenoid terminals are 30 and 'S'. I thought about taking the 3 wires off the foot switch and connecting them to the three '56' terminals of the relay.
Do you know where I can pick up a connection for the flasher on the steering column?
Have not studied wiring diagrams yet...

Thanx
naj

65 230SL
68 280SL

[jeffc280sl]

Hi Naj,

I mocked the circuit and installed it on my car.  The results were not good.  The latching relay didn't seem to work. I would trigger the relay and it would only latch in one direction.  I switched the wires from high to low beams and the switch followed. The VW relay I purchased was made in Brazil and is of poor quality.  I've taken it apart and concluded the mechanical latching tolerance is poor and unreliable. I'm looking for a better relay to finish my project.

Items to note:
The relay I purchased included a separate contact to flash the high beams.  I was wondering how I could preserve this function.  The relay took care of this issue but was poorly made otherwise and I would not recommend using it.  The VW relay was also a neg input relay.  It looks for a momentary ground pulse to toggle between high and low beams.  Our stalks put out a plus signal so I needed another relay to convert the plus output from our stalk into a neg input for the dimmer relay.  

I would like to find a high/low beam relay that accepts a plus pulse
so a second relay is not needed.  The numbering on your relay is a good indicator.  It was the same on mine.  56a and 56b denote high and low beams.  Can't remember which is which off the top of my head.  I used the wires from my footswitch which carried the same numbers.  The 56 wire comes from the head light on/off switch and provides the plus signal that is toggled between 56a and 56b exactly like your footswitch. My stalk harness had been modified previously so that I enabled the flash function. I used the wire from this mod which was connected to pin #8 on the stalk connector as the plus input to the first relay.  This signal was then converted to a neg input to the second relay which switched power from 56 to 56a and 56b.

I hope this is clear enough.  If not ask a question.  Please let me know the source for the relay you purchased.  I found another relay for VWs made in Germany by Meyle (sp?).  I'm hoping it is of better quality.

Jeff C.
1970 280SL 4-speed

[Naj ✝︎]

Hi, Jeff,
Meyle is an OE supplier of good repute - so the product should be good quality.
The relay I got is from a UK manufacturer 'Durite'. I tested it last nite on a 12V power source (Battery Charger) and the switching does work, toggling between 56a and 56b. The '+' feed for the solenoid (30) is independant of the 56 terminal, so I think it should work  with the 12V+ signal from the h/lamp flasher.
Will let you know how I get on when I get a chance to try it.

Silly question but did you disconnect the wires from the foot switch?

naj

65 230SL
68 280SL

[jeffc280sl]

Naj,

My 56 and 30 terminals are separate as well. Just thinking about my relay. Now that you have prompted the idea I don't see why I couldn't tie S to ground and take the plus input from the stalk on 30.  Don't know why I didn't consider it earlier and avoid the other relay.  I did disconnect the footswitch.

Jeff C.
1970 280SL 4-speed

[A Dalton]

If the relay does not have internal connection from contactor circuit and coil circuit, it can still be wire from a pos coil feed .
 It is when a common grd  for both inside the relay is used that you can not work around it..

[Naj ✝︎]

Here's a schematic.
Hope its legible.



Download Attachment: LatchRelay.jpg
82.18 KB

naj

65 230SL
68 280SL

[A Dalton]

That will work..

 http://www.premierwiring.co.uk/UDP12.htm

[jeffc280sl]

The schematic looks good.  As the solenoid is energized by pin S and 30 the main switch toggles between 56a and 56b.   The VW relay schematic has a second switch fed by pin 30.  As the solenoid is energized this second switch closes to conect pin 30 to 56a. This switch enables the flash function for high beams.  30 is hot from the stalk even when the light switch power to 56 is off.  This way the flash function will work when the headlight switch is off.



Jeff C.
1970 280SL 4-speed

[Cees Klumper]

This whole thread is incomprehensible to me. I believe we have now reached a higher plane. But I do have one question though - why not stick to the floor switch for turning on/off the high beam lights?

Cees ("Case") Klumper in Amsterdam
'69 white 280 SL automatic

[A Dalton]

Originally posted by Lax882@aol.com

The schematic looks good.  As the solenoid is energized by pin S and 30 the main switch toggles between 56a and 56b.   The VW relay schematic has a second switch fed by pin 30.  As the solenoid is energized this second switch closes to conect pin 30 to 56a. This switch enables the flash function for high beams.  30 is hot from the stalk even when the light switch power to 56 is off.  This way the flash function will work when the headlight switch is off.


That is the Ticket... I don't want to loose that feature ..
 Is that just an extra contactor set actuated by the same coil??  Must be.
 Old Volvos have the same system

 Got a VW schematic?
Tnx

[jeffc280sl]

It is activated by the same coil.  VW Part No.: 111 941 583
Meyle cross references this part number to Meyle No.: 100 941 0006

This relay is used on a bunch of Audi and VW cars.  I'll scan the schematic and send it to you Arthur.  I can't post pics here.

Jeff C.
1970 280SL 4-speed

[A Dalton]

quote:Originally posted by Lax882@aol.com

It is activated by the same coil.  VW Part No.: 111 941 583
Meyle cross references this part number to Meyle No.: 100 941 0006

This relay is used on a bunch of Audi and VW cars.  I'll scan the schematic and send it to you Arthur.  I can't post pics here.

Jeff C.
1970 280SL 4-speed

 Cool . that is how they got around the extra switching.. which is perfect for this application

 I would like to see the schematic , if you could [ I already have it in my head , but theirs would be nice ]
Tnx

[Naj ✝︎]

quote:But I do have one question though - why not stick to the floor switch for turning on/off the high beam lights?

Cees,
It becomes a bit difficult to control both the clutch pedal and foot dimmer switch in high density traffic situations. Autos are of course easier as one has a spare foot.
I guess it was okay in the 'old days' when traffic was lighter and drivers did not know better   .
Now they are spoilt by modern technology  

naj

65 230SL
68 280SL

[Ben]

I've been keeping a close eye on this thread since its inception !  When you guys are done could you provide and exact "how to" guide so I can do this mod, as I said earlier getting my Doc Marten boot down there is impossible most of the time !  

Regards,
Ben in Ireland.
'64 230SL 4sp.

[TR]

Guys -- I'd like to 2nd Ben's request for a "how to guide".  I've no doubt this hidden enhancement you're coming up with will significantly improve the MMI (man-machine-interface) aspect of hi/low beam switching, as well as provide a releated increased safety factor, of our W113s...especially for those cars with clutches.

Thanks for the fine work you're doing and letting the rest of us know about it.

Tom in Boise
'71 280SL 4-spd, signal red w/lt. tan interior, restored/enhanced

[Naj ✝︎]

JeffC / A Dalton,


 

quote: That will work..

 

quote:30 is hot from the stalk even when the light switch power to 56 is off. This way the flash function will work when the headlight switch is off.

Hmmmm, slight problem:

When high beam is on, 56a (high beam feed) will also energise terminal 30 on the relay - hence no more switching   .

Jeff, I believe you already experienced this with your mock-up???

Fix:
1. Use stalk only for switching hi/lo beams and disconnect feed to hi beam for flashing (Also wire 56a in MB wiring diagrams)
or
2. Use a (zener ??) diode to the flashing hi beam feed to stop it feeding  terminal 30 on new relay.

If you agree, how does one decide which diode to use.

Can you tell I got an 'F' in Electronics 101?

naj

65 230SL
68 280SL

[Ben]

Will the switch not work so that you pull it back for high beam then pull it back again to return to low beam. This is how all those old VW's worked AFAIR !

Why would you need a separate "flash" facility ?

Regards,
Ben in Ireland.
'64 230SL 4sp.