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Old 04-07-2014, 07:33 PM
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300SD81 300SD81 is offline
1981 Mercedes-Benz 300SD
 
Join Date: Aug 2006
Location: University of Georgia
Posts: 1,082
Flasher Relay mod for LED bulbs.

Took a little work to figure this out, so thought I'd share for anyone interested.

The flasher relay can be modified pretty easily to flash at a normal rate with LEDs.

2x 1-ohm resistors (in parallel) are put in series with the 30-milliohm sense resistor, so the U243B chip detects a higher voltage drop and flashes normally.

Note that this makes it no longer function and possibly overheat if you use normal bulbs, but it is easy enough to undo or even drill the relay casing and wire a switch to change between.

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Ich liebe meine Autos!

1991 Mercedes-Benz 560SEL | Megasquirt MS3-Pro | 722.6 transmission w/ AMG paddles | Feind Motorsports Sway Bar | Stinger VIP Radar | AntiLaser Priority | PLX Wideband O2 | 150A Alternator | Cat Delete
1981 Mercedes-Benz 300SD | Blown engine, rebuilding someday...
1981 Mercedes-Benz 300SD | Rear ended, retired in garage.
2009 Yamaha AR230HO | Das Boot

Excessive speeding? It ain't excessive till I redline!

Last edited by 300SD81; 04-07-2014 at 07:45 PM.
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