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Smart Flash Module & Lights Testing
by “MC7”
Testing Lighting on an AIH with a Smart Flash Module Without getting into the "fancy" aspect of the Smart Flash where it flashes brake lighting, let's first understand the system basics. Think of the module as having remote controlled "switches" inside of it (relays). When something directs the module to do something, it closes or opens a switch (relay) and it is these relays which in turn provide power to the actual lights. The module is mid-stream between the handlebar switches and the lights and this type configuration is known as "in series". For example, +12V goes to the handlebar controls including the left and right directional switches. When you operate a handlebar directional switch, you are allowing the +12v to pass through the switch and be sent through the wiring to the Smart Flash module to COMMAND it to do something ... turn on left or right directional lights. The +12 voltage coming from the handlebar and going to the Smart Flash Module are known as "command voltages", and as such the wiring carrying command voltage ONLY goes to the Smart Flash Module - and NOT directly to the lights. Once the Smart Flash module has received a command voltage, it activates a relay which allows +12v to turn on a directional light. Same thing with the brake switches, they too send command voltage to the Smart Flash module to have it activate the brake lights. One way to begin testing is to disconnect the connector from the Smart Flash module. This also allows you to look for corrosion within this connector. Ir present, clean it using electrical contact spray cleaner and then dry thoroughly. If you are going to troubleshoot electrical systems, you need to arm yourself with a DVM ("Digital Volt Meter") which are available these days for less than $8. If it also reads resistance ("Ohms") and current ("Amps"), better still. With the connector halves separated, attach the black negative meter lead to a solid ground connection. Check by touching the red meter lead to the plus side of the battery as this makes sure the ground path makes it all the way back to the battery. Touch the red lead to the Orange wire on the harness side of the connector. You should read +12V. This is the +12V supply to the Smart Flash Module ("SFM"); if not present, look for +12v at the other end of the Orange wire at the Power Control Module ("PCM"). If present at the PCM but not the SFM, check the Orange wire which goes through a connector to the handlebar controls. Separate this connector and again look for corrosion. Now put the red meter lead on the brown and violet wires on the harness side of the SFM connector and operate the handlebar turn switches and as each switch is activated, you should see +12V command voltage. If you don't, check the wiring and the handlebar connector just mentioned. Re-mate the SFM connector halves. If there was corrosion, cleaning may have solved your issues. If not, disconnect the connector halves which goes to the rear lights. Check for +12V on the brown wire with white stripe (right directional) and violet wire with white stripe (left directional). Applying either hand or foot brake sends a +12V command voltage to the SFM, which in turn sends +12v through both the brown wire w/ white stripe and violet wire w/ white stripe which lights up the the brake lights. The SFM also knows how to allow one lamp to be bright while the other is blinking such as when braking with an activated turn signal. The PCM, and NOT the SFM, supplies +12V to the license plate light as well as the tail lights through two blue wires which are common (tied together) on the harness half, but are two individual wires on the lighting half of the connector with one blue wire going to the plate light and the other going to both tail lights. It is conceivable that you have +12V on the harness side, yet only one blue wire on the lighting connector half is getting voltage (corrosion, damaged pins, wiring, etc.). Check these voltages at both the PCM connector and rear lighting connector. Front lighting is pretty much the same as the rear as far as the running and turn lighting is concerned. It doesn't hurt to disconnect the front lighting connector and inspect for corrosion. If you are blowing PCM fuses, check your wiring, and isolate the troubled area by disconnecting the previously mentioned connectors. If upon mating a connector and a fuse blows, you are getting close. Places to look for shorts are between the license plate and the mount; inside the lamp shells/sockets' connectors; switches, wiring (under the rear fender, and any place where wiring can be pinched or chafed.  Also, changing lighting to higher current consuming lights can be problematic, so be careful.
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Smart Flash