indicator pilot light issues

[simonster]

I have rewired the loom with no issues on my 72 500 k1 apart from the indicator pilot light on handle bar light cluster. The wiring diagram I'm working with suggests the orange and light blue wires on either side of the cluster light is wired in parallel ie LB to LB and O to O circuits but this means creating a bypass to the handlebar switch and when I tried this it does cause a live feed albeit reduced to the opposite indicators. Logically the pilot light should be earthered from both LB (right indicator) and O ( left indicator ) circuits but am I missing something? Cheers

[Lobo]

Hi Simon...

Wiring issues always so hard to put into words! Furthermore I don't have a '500.... but am assuming most Hondas abouts that era were wired roughly the same.... so have included a CB400F diagram.

As I read it, a live comes from the flasher unit into the handlebar switch. Depending upon your L/R selection on said switch, this live feed then exits via the Orange OR Light Blue wire to the respective indicators... through them... and down to earth, completing the circuit.

Let's assume you make a LEFT selection....

Black live into flasher unit....(white?) out to handlebar switch.... now out via Orange wire to both Front & Rear LEFT indicator lamps. From here through the bulbs... and to earth.. L indicators flashing.

This orange switch feed ALSO goes directly to the pilot lamp, through it, now out through the LIGHT BLUE to the R indicators... through those bulbs & to earth. The indicator lamp now also flashes.

BUT, because it is only 2 Watts, versus the indicators combined 36W, it flashes.... the indicator bulbs - as far as the weeny pilot lamp is concerned - may as well be a fat earthing wire.

And when you indicate in the other direction, the pilot lamp circuit is simply reversed, but with the same outcome.

I guess the proof of the pudding would be to remove the two (R) indicator lamps & select a Left turn. The L flashers should work normally, the pilot lamp.... denied of its earth... would not.

I hope I understood your question, otherwise apologies.
Simon.

[Bryanj]

Might seem strange but it does work that way BUT they need to be connected in the headlamp shell

[simonster]

Thanks lobo, that does explain the logic behind the original wiring and has identified the problem I have added to the mix....due to using low watt LED lamps as replacements to the old filament bulbs. The new LED bulbs have similar wattage to the pilot bulb so are drawing enough amp to dimly flash too. I will try an LED pilot bulb which may resolve the issue and will report back. Cheers.

[hairygit]

I'm afraid the old style flasher unit on the sohc fours WONT work properly with led bulbs, they rely on the draw of conventional bulbs (21w in the indicators) to work the bimetallic strip in the flasher unit, try it with conventional bulbs!

Sent from my GT-S5839i using Tapatalk 2

[simonster]

I did anticipate the winker issue so bought a flasher to suit LED and it flashers fine the the new bulbs. That said I have just tried an LED pilot bulb and it doesn't solve the issue with amp draw to the opposite circuit. Cheers for the advice.

[Lobo]

Yea, that's a pain. Simplest way 'round this one might be 2 pilot lamps (if space in the binnacle), each wired in parallel (& with its own earth) to its respective indicator circuit.

But you've already worked that out...

Bryan... you describe the circuit as 'strange'.... I'd say "cunning"!

[simonster]

Yes strange or cunning is a apt descriptive term for genius and ingenuity behind the Honda fours. I intend to dig out my old micro electronics kit, children's edition and rig up a two led twin circuit mirco lamp to fit, or else accept it to work in one direction only.