Pagoda SL Group

W113 Pagoda SL Group => Electrical and Instruments => Topic started by: jeffc280sl on June 30, 2005, 12:58:54

Title: headlight dimmer
Post by: jeffc280sl on June 30, 2005, 12:58:54

I have a 4 speed and the dimmer switch is hard to get to sometimes.  I've been researching the possibility of adding a latching relay so that I can use the turn signal stalk to dim the headlights.  I think it can be wired so that I can preserve the flash function I added to the stalk switch some time ago.  The latching relay will take a momentary input from the flash switch on the stalk and "latch" and keep a cicuit on.  A second momentary input will "latch" the circuit off.  The light switch provides main power to the relay and inturn the headlights.  In the "on" condition the relay would power hi beams.  In the "off" condition the relay would provide power to the low beams.  Control of the relay will take place by the momentary flash switch contact on the stalk.  I ordered a $25 relay yesterday that is used in a similar cicuit on older VWs.  I'll let everyone know how it goes when I get the relay and wire it up.  I'll hide it somewhere so that it can not be readily noticed.



Jeff C.
1970 280SL 4-speed

Title: Re: headlight dimmer
Post by: gugel on June 30, 2005, 13:15:10

Jeff,

I have the same problem -- my foot doesn't fit too easily around the clutch to get to the dimmer -- so I'll be very interested in the details if you can get your steering column dimmer switch working.

Chris

Title: Re: headlight dimmer
Post by: jeffc280sl on June 30, 2005, 13:37:29

Hi Chris,

I'll let you know how things go.  It should work.



Jeff C.
1970 280SL 4-speed

Title: Re: headlight dimmer
Post by: A Dalton on June 30, 2005, 19:15:25

Latching on with momentary sw input can be done with a SCR circuit , coupled with some switching transistors for latch off , both from momentary sw inputs .. using the same sw in the stalk

 Here is a basic ciruit.. values would have to change .. 12v in and
a relay primary coil for load. Stalk sw for momentary sw.
 This could be in parellel to existing cicuits , but you may loose flash to pass with  single hold. Could just do a double click.
 Interesting concept..

 www.edn.com/contents/images/102804di.pdf

Title: Re: headlight dimmer
Post by: Tom on June 30, 2005, 19:47:58

I have an auto tranny so I don't have the same issue.  I prefer the foot operated high beam over the stalk unit.  My foot is always near the switch-my hand is not always near the stalk (one handed driver).

1971 280sl Tunis Beige Metallic (restored & enhanced)
1971 280sl Tobacco Brown (low mileage stock)
1970 280sl Deep Red (Project Car)

Title: Re: headlight dimmer
Post by: TR on June 30, 2005, 21:55:26

Jeff -- Sure sounds like a good concept to me.  I've long noticed the same problem.  Look forward to reading what you come up with.

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

Title: Re: headlight dimmer
Post by: Ben on July 01, 2005, 02:21:03

Yep .........count me in too !

I simply cant get my size 11 Doc'Martens near the switch !

I end up either not driving in the dark or holding the flash switch!

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

Title: Re: headlight dimmer
Post by: jeffc280sl on July 01, 2005, 07:08:55

Thanks Arthur,

I'm amazed at the stuff you come up with.  Maybe this is just a 4 speed issue.  I've owned both and would not part with my manual.  Ben and Tom (Boise), I'll let you know how things go.  Sure would be neat to find a inexpensive feature that does not look anything but original.

Jeff C.
1970 280SL 4-speed

Title: Re: headlight dimmer
Post by: A Dalton on July 01, 2005, 08:57:33

JC.
 The transistor SCR circuit would be on a  very small PC board
and hidden somewhere..
 I also often though that one might go with a mechanical mod to the stalk sw by adding some kind of detent fixture/arrangement ..
 That would be the coolest..