Topic: '76 CB550K front left signal light not flashing

[denward17]

I assume there is  replacement turn signal on my bike, as the left front has a red/black wire coming out.  The wiring chart indicates it should be orange and orange/white.

The right side signal light is color coded correctly (LB - LB/W).

I've replaced the flasher under the left side cover with an automotive type.

I think the base of the turn signal is damaged, so will probably just buy another turn signal.

Symptoms:
With key just on or running, both front turn signals are on (running lights).  When I switch the right side on, running light goes out, both front and back flash, although somewhat slowly.

When I switch left side on, the left front running light goes out, no flash in front, but the left rear does flash, somewhat slowly.

The blinker indicator on the dash panel works with either side.

The flash beeper might beep twice then it stops, on either side.


I assume I can rule out the flasher and pretty much all else since everything works except the front left turn signal?

.

[willbird]

Your TS bulbs I'd presume are just single element bulbs ? Should not be any running lights ??

[denward17]

Not sure when they started with running lights, but yeah, this one has it, 2 filaments per bulb.

I switched the front bulbs with no change, both bulbs work on right side.

I did unplug the flasher buzzer/beeper, and the speed of flash did pick up faster.

I then started to move the switch just a little slower, with clicking all the way left, then I hear a tick sound, then nothing worked, blew the main fuse.

I decided I needed to open up switch to see what it looked like and found what looks like a dirt dauber nest.

This could be my problem?

[newday777]

Your TS bulbs I'd presume are just single element bulbs ? Should not be any running lights ??

Front have dual filament bulbs.
Rear are single filament.

[newday777]

Yes Den clean out that switch.

[willbird]

Your TS bulbs I'd presume are just single element bulbs ? Should not be any running lights ??

Front have dual filament bulbs.
Rear are single filament.

In the US of A in 1972 ?? I do not recall mine ever having dual element, and the wiring diagram posted here shows only one function ??

http://manuals.sohc4.net/cb750k/technical_reference/WD750K2.jpg

Oops my mistake, 550 vs CB750K differences ?

Bill

[denward17]

Will it hurt anything just to unplug the flasher beeper?

[carnivorous chicken]

Will it hurt anything just to unplug the flasher beeper?

Nope. Just make for fewer headaches and stares at stoplights.

I'd check the ground too, make sure it's clean.

[grcamna2]

Will it hurt anything just to unplug the flasher beeper?

Nope. Just make for fewer headaches and stares at stoplights.

I'd check the ground too, make sure it's clean.

The ground connection to the left turn signal and the -ground path in the switch/handle bars.

[bryanj]

If your problem blinker has only a red/black wire comming out of it that is your problem as it need 2 wires feeding a 21/5 dual filament bulb and socket

[denward17]

If your problem blinker has only a red/black wire comming out of it that is your problem as it need 2 wires feeding a 21/5 dual filament bulb and socket

Maybe I didn't spell it out clearly enough, there are 2 wires, one black and the other red, assume it is an aftermarket unit.  I have ordered a replacement unit and will clean out switch tomorrow.

I think it is the turn signal unit as one of the wires came out of the base, I tried to solder it back in place, but think I created a short because every time I turn on the left signal now, the main fuse will blow.

[bryanj]

Ah you said red/black which means red with a black stripe what you mant was one red one black

[denward17]

I took the turn signal switch apart and cleaned it with contact cleaner, little dielectric grease and put back together.

Unplugged the front left turn signal, turned on the ignition and turned the blinkers on, they still work and the main fuse did not blow this time which tells me the turn signal itself is messed up.

Got one on order so should be here early next week to try again.


With the aftermarket turn signal, it will probably have a black wire and a red wire (2 filament), does it matter which lead I plug into the orange wire at the harness?

[bryanj]

YES you will need to test it but the dim filament goes to the white stripe the bright filament goes to the solid colour

[denward17]

YES you will need to test it but the dim filament goes to the white stripe the bright filament goes to the solid colour

Is the dim filament the running light?

[BenelliSEI]

YES you will need to test it but the dim filament goes to the white stripe the bright filament goes to the solid colour

Is the dim filament the running light?

Yes. Does the lamp have a good ground. Just mounting it to the headlamp shell and fork ear (rubber mounts top and bottom) won’t do it…….

[bryanj]

The ground is the green wire on the shell retaining nut connecting to ear via the steel sleeve and loom

[denward17]

Got the problem solved....

I had 2 problems, the base of signal light wire that had broken, I re-soldered and it was shorting out, blowing main fuse.

Installed new turn signal, still didn't work.  Checked ground wire that is connected to the fork ear, it was almost plugged in, but not enough, after reseating the ground wire it works.

Appears good to go now.