Hi everybody,

I’m new to the online forum and have an issue I’m running into. I have a 1990 FLSTC, and I decided to put new bars, switch housings, and hand controls on.

I have everything installed and the switches are wired up. Just about everything is operating correctly but the turn signals. When I hit the signal button they illuminate solid but will not flash. I have figured out that the originals must have been a two wire connection because there was one wire left over from each side and it is green. If I jump the green wire to the signal wire, they flash as they should.

I can’t be the only one who has done this mod. Can someone please help??

 

From what I can see on the wiring diagrams, the green wire should be power from the flasher unit. That GN wire brings flashed power to the right directional switch. When the switch is pressed power should go from the switch (to the directional bulbs) on a BN (brown wire for the right turn signal. That appears to be the stock 1990 setup. Now the newer bikes have a turn signal module instead of the flasher unit so things work a little different. For the new right hand control, power to the switch is the O/W (orange/white stripe) wire. Power to the turn signal module is the W/BN wire. I would try feeding the turn signal switch with the GN wire to the O/W wire. Then connect the BN wire to the W/BN wire from the switch and see if that works. Good luck. Post what happens.

 

I just did this on my `89 Softail...

The difference between the turn signals on your bike and the later bikes is the older bikes used a simple signal flasher.

The flasher sends power to the green wire, which went to both sides. When the turn signal button was pushed, it simply closed a circuit to ground, and the lights would flash.

The newer models use a turn signal module. Each side gets its own power supply from the turn signal module, this is where we will make the change.

Your`re not going to like the next part (don`t worry it`s not that bad)...

Disconnect the connector, unpin the wires from the plastic connector...

Slide the plastic cover off the switch wires.

R/H Side:
You will see that the orange/white wire branches off to two switches, the turn signal switch and the brake light switch.

You need to cut the wire that goes to the turn signal switch, the cut is made after the spot where the wires branch out to the switches. You will now have a short wire coming from the turn signal switch, and the long wire going to the brake light switch.

Cover the cut portion of the wire going to the brake light switch with shrink wrap.

Connect a length of wire to the short wire coming from the turn signal switch (preferably a green wire).

You can solder if you prefer, but I crimped a small Deutsch pin on one side, and a Deutsch socket on the other side, plugged them together and covered with shrink wrap.

Crimp a socket on the green wire, slide the plastic cover over the wires, reinstall the wires into the connector.

Make sure the colors match. Green to green, orange to orange etc, the colors wont be exact, it will be orange/white to orange, red to red/yellow, you get the idea.

On the L/H side, the orange white wire branches off to the turn signal and the horn switch. Same idea here, leave a short wire on the turn signal switch.

Add a length of green wire etc.

Crude diagrams:

Cut O/W wire here:

 

If I’m reading this correctly, I need to do this in the switch housing, correct? So the green wire will now be the “power” wire for the turn signal instead of the orange/white?

 

Splice green wire to short O/W wire

 

It will be done in the switch harness, but not all the way inside the switches, you will see where the wire branches once you slide the plastic cover off the wire harness.

Yes, you will be using the new green wire for power to the signal switch, and leaving the o/w wire intact for the stop lamp on the right side. You will leave the O/W wire intact for the horn on the left side.

 

Thank you so much. My head was spinning with ideas. I had diagrams out for bikes that have the newer style switches thinking about trying to get a Turn Signal Module installed. Lol

 

It looks like a lot when you read my description, but it is really very easy.

The worst part is de pinning the sockets from the connectors. Once that is done you can just slide the cover off the harness and you will see where that orange/white wire branches out to the two switches.

The new model switches are worth the effort...

 

Question: Have to switch out the master cylinder and clutch perch to the newer style also? YD

 

Yes, the old style hardware does not match up to the later switch housings.

On my `89, I wanted to change from 5/8" to a 9/16" Master Cylinder, so I had to change out everything.

The 5/8" Master Cylinder made the effort needed to pull the lever very high, it stopped like a truck.

In `96 the factory changed the single disk Master Cylinder to a 9/16", which made a huge improvement in the front brake.