Pagoda SL Group
W113 Pagoda SL Group => Electrical and Instruments => Topic started by: Larry & Norma on May 24, 2018, 18:51:00
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My 280SL has a hazard switch that looks like a dealer install, does anyone know how this was wired?
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maybe this helps
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Thanks, just trying to get the emergency flashers working after converting to LED indicators.
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Hi Larry,
have seen this info in the technical manual?
https://www.sl113.org/wiki/Electrical/FlasherRelay
Also perhaps these long discussions here might help:
https://www.sl113.org/forums/index.php?topic=17648
https://www.sl113.org/forums/index.php?topic=22863
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Thanks Alfred, my searches missed most of that!
It looks like no-one has fixed the emergency flasher working as yet.
The Mercedes switch is quite complicated and has its own internal flasher requiring the load resistance of
filament bulbs.
With LED's a 3pole changeover switch and 3 diodes could be used, if such a switch was available similar to the Mercedes.
Additional wiring would be required.
Now for a search for a suitable switch...……….
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There are 2 ways to fix this.
You can install a 2 pole electronic LED flasher in series on the power wire feeding the hazard switch/relay. This works because the Hazard flasher contacts default state is closed when the knob is pulled. Only when a significant load is placed on the relay will the internal spring heat up and break contact to extinguish the bulbs. Once cooled (milliseconds), the spring contact again closes and lights the lamps. This process of opening and closing give you your flasher function. The higher the load, the less "On" time the bulbs will have.
Or you can install a 6 ohm dummy load (resistor) at each tail light signal socket OR each front turn signal socket.
This second option also allows the turn signals to use their original flasher relay. Ideally you would want to find loads that equal about 36 watts including the LED's. A 4 ohm load resistor at 12 volts will draw 36 watts. (LED bulb wattage X 2 + load wattage) However, Bulbs in our cars are 18 watts each and there are also voltage drops in the wiring as well as the peanut bulbs in the dash. A readily available 6 ohm load resistor will suffice. Installing them in front will make them less visible as well as not having to cut any wires. Simply solder them between the lamp socket power and ground wires. The drawback of this setup is they still consume the same power as incandescent bulbs.
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Hi Tyler,
I am aware of this get out but wanted to solve the problem without resorting
to dummy loads.
I have a switch on order which will hopefully help me produce a solution.
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Then a 2 pole flasher designed for LED's wired into the power feed to the existing hazard switch will work. You leave the existing hazard switch in place and operate it via its original push/pull function. You can remove that peticular wire/pin from either end at a connector and make a small jumper harness with the new flasher so no wires will need to be cut.