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Old 12-15-2012, 11:17 AM   #232
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Joined: Aug 2010
Location: Las Cruces, NM
Oddometer: 1,169
Originally Posted by Stan_R80/7 View Post
Ok. To clarify, I do not have the SM-1 relay. I just want to understand how it works before converting all the (working) turn signals and running lights.

My understanding is that the SM-1 relay - acts like a relay (i.e. an electrically powered switch). In that there is power from the green/black wire and brown to energize the relay, then the green/yellow (from the switch) wire activates the relay (i.e. throws the switch). The black/white wire gets its original signal from the Hella turn signal relay - which makes me think the SM-1 relay also must put out a signal to the dash bulb.

But, I don't know. I can only guess about what makes sense per the standard wiring diagram, this post, and the instructions. Hooking the black/white wire directly to the green/yellow (switch) wire bypasses the SM-1 relay (and original Hella relay) based on the /7 or /6 wiring diagram.
If you have a different model signalMider (not an SM-1) you will need to call Andy at Kisan. Your understanding of the SM-1 function is basically correct, but think about it this way - green/black is positive power to the relay, brown is ground, green/yellow is positive power output FROM the relay to the bulbs. If you connected the green/yellow directly to a bulb and grounded the bulb (closed the circuit), the bulb would flash. This is the function of the turn signal switch, it closes (or completes) the circuit to the bulb, it sends the power from the green/yellow to the bulb. When the SM-1 "senses" the closed circuit it sends the "flashing" power out to the green yellow wire. Clear as mud? Study your wiring diagram so you understand the turn signal circuits. Now to the black/white wire - if you connected the black/white to the SM-1 power OUT-PUT terminal (the green/yellow terminal) then it would cause the signal indicator bulb to flash; but this is the problem, there is no way to turn it off, it would always be flashing, because it is always a closed circuit. So, I see your point. Tying the black/white to the green/yellow will not work. Here is a way around the turn signal relay - if you connected the black/white to a turn signal wire (blue/red or blue/black) the indicator bulb would flash with the signal bulb. So, from the circuit board in the headlight bucket, run wires with a diode inline from the blue/red and from the blue/ black, and tie both of them to the black/white. Clear as mud? If you connected the black/white only to one side (blue/red) then the indicator would only flash when that one side was flashing. If you connect a blue/red and a blue/black to the black/white WITHOUT diodes inline then the both right and left turn signals would flash at the same time. Can I make it any more confusing?
ABC #12947
'75 R90S

craydds screwed with this post 12-15-2012 at 11:30 AM
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