Topic: 1973 Honda CB350f, Turn Signals Will Not Flash When Bike is Stationary

[zcb350fb]

Hey guys. My turn signals will not flash when the bike sits at a standstill. The turn signals do flash when the bike is moving.

I never use the turn signals anyways. I always use hand signals to indicate turning instead. I feel like cars will notice that more than a little flashing yellow light.

Anyways, i need to take my road test at the dmv to get off of my learners permit. I am in sc and we have no vehicle inspections but when you take the test, the high beam, low beam, turn signals, horn and break light all have to work. Do you all have any easy fixes to this? Would it be better to get some after market turn signals?

None of my friends have bikes so I don’t know anybody who would let me borrow a “better working” bike to use for the test

[b52bombardier1]

Its going to be dirty connections in your wiring, probably on the ground side of the turn signal circuit.   You could run a temporary length of wire from the negative battery post to the turn signal lamp base to see if that solves your problem. If that solves it, start cleaning up things. 

  Otherwise, how old is your battery? What does your electrical system indicate for voltage at the battery with the engine running at idle and maybe half throttle?  The higher RPM when your bike is moving is developing more wattage out of the engine generator perhaps "burns through" your dirty connections enough to make your turn signals work.

  I have also seen turn signal and brake light wires that look good externally - the insulation looks perfect.  Yet, at the connectors, they have many broken strands of copper internally. Even one single strand of good copper will still pass a continuity check on a multimeter but is actually a point of high resistance for lighting. Seen this a lot on my old six volt Honda bikes where electrical power production is often critically low.  I had to buy a Honda connector kit from "Vintage Connections.com" to sort out these problems.

Rick

[Sigop]

For my '73 750 it's always been a low battery when they blink very slowly or not at all at stop, but will blink when running.

[jlh3rd]

And the same for my 75 550f, unless it’s a brand new ,fully charged battery or a fully charged ,good battery.
     If you want a simple test, turn your blinkers on at idle, in neutral, rev the motor past 3 or 4 thousand and if the blinkers start to blink...I’d then look at how good your battery is first...then connection and broken wires.
   

[ohiocaferacer]

The turn signal relays on these old bikes are load relays and will only blink when the electrical system are at 12 volts. Increase the rpms a little and see it the signals blink. If so.....that's normal. At idle a lot of times they won't blink.

There are a couple places online that offer replacement digital relays and you can swap it out if you want.

[TwoTired]

The stock two terminal flasher is voltage sensitive.  And the alternator doesn't make full power at idle.  So, the battery is at its lowest voltage at idle.
Further, as mentioned, the connectors and switches get lossy over time and that loses voltage in distribution.

I use the slow flash rate to tell me when the battery is low, so I can keep the engine revving at long lights and the battery up.   Others replace the flasher unit with an electronic one that isn't voltage or load sensitive.

Your choice.  I'd refurbish the power distribution system so everything gets full battery voltage. (you'll get a brighter headlight, too.)

Cheers,

[KB02]

The turn signal relays on these old bikes are load relays and will only blink when the electrical system are at 12 volts. Increase the rpms a little and see it the signals blink. If so.....that's normal. At idle a lot of times they won't blink.

There are a couple places online that offer replacement digital relays and you can swap it out if you want.

They should blink regardless of whether you are at idle or revved up. I won't call not flashing normal. Slow, yes, but not working at all, not so much. In either case the basics of what you say it right on. Most likely low voltage causing the flasher not to flash. Replace with digital and away you go. (Plus, diagnose charging system health to make sure things are up to snuff.)

[Keith]

Change the flasher.

[Deltarider]

If the bulbs happen to be 25 Watts, I'd change them for 21W or better even 18W like other markets had. I wouldn't be surprised if it is in print on the relay. On the one I have here (from a CB350F) it says 18W X 2 + 3W. BTW, there were no less than 4 different relays on the CB350F for various markets. Don't worry, they'll be noticed just as well. The standard stop/taillight here is 21/5W.

[zcb350fb]

Thanks for all the info guys. I picked up a new flasher generic flasher at Reilly’s and the turn signals work now.

Now time to take the test.

Thanks as always!