Honda Twins banner

1 - 4 of 4 Posts

·
Registered
Joined
·
32 Posts
Discussion Starter · #1 ·
Hello,


I have a 1971 cb 350 and it recently started having weird blinker problems. Sporadic speed increase and decrease.. So strange. Any suggestions?
 

·
Premium Member
Joined
·
3,006 Posts
Check your ground connections.

Easy way is to make up an Jumper with alligator clips both ends and ground directly to the battery.

If it suddenly works right then you can go back and chase down the REAL Grounds.

Adding extras is also a good idea.

Also could be a simple flasher unit.

If you have the OEM Type you can switch to an electronic one at any auto parts store unless you are a purest.
 

·
Registered
Joined
·
32 Posts
Discussion Starter · #3 ·
A jumper? I am NEWB for real. Could you elaborate? And will just a plan flasher unit from a parts store suffice?
Check your ground connections.

Easy way is to make up an Jumper with alligator clips both ends and ground directly to the battery.

If it suddenly works right then you can go back and chase down the REAL Grounds.

Adding extras is also a good idea.

Also could be a simple flasher unit.

If you have the OEM Type you can switch to an electronic one at any auto parts store unless you are a purest.
 

·
Premium Member
Joined
·
3,006 Posts
A jumper is just that a long piece of wire with Alligator Clips both ends - nothing fancy. The purpose here is to provide a KNOWN GOOD GROUND PATH for the Blinkers.

The Rear Blinkers have a dedicated Ground Wire (BLACK in the OEM Harness) that comes from the Clamp Bolt that squeezes the Housing onto the stem and keeps it from turning, to the main wiring harness. The Rears use a separate dedicate ground because the are rubber shock mounted and insulated from the frame.

The Fronts use a much more complicated route for the ground.
The mount to the headlight support ears, which are grounded via the bolts that hold the headlight, The Nuts for those bolts have ground wires inside the headlight housing. Those ground wires (Green this time) Connect into the Main Harness and eventually to a frame ground.

By Clipping one end a wire to the Metal body of the Blinker Light housing and the other end directly to the Battery (Neg "-") Terminal you have a KNOWN GOOD GROUND.
Under that condition if you can power the bulb (make it light up) and it doesn't blink (make sure you have both blinkers on one side grounded this way or you might not draw enough current).
It's NOT the Ground it would almost certainly be the Flasher Unit.

The Flasher is basically a self resetting circuit breaker.

It has a Bi-Metal Strip (two layers of different metals) When you pass current thru the strip it heats up and bends because the (2) metals expand differently.
When it bends it moves one end away from the incoming Power lead and OPENS the circuit.
it then begins to cool.

When it's cooled down enough it bends back and re-connects to the power side and passes current to the bulb - the bulb lights up and the process starts over.
Bulb turns "ON" -> Strip Heats Up - > the circuit goes "Open" -> The bulb turns "OFF" -> Strip Cools down and Closes the circuit -> The Bulb Lights Up . . . .

The bi-Metal strips eventually fail and stop bending (ones side breaks) and they either don't light up or they don't turn off. They can fail either way.

Electronic Flasher use a CHIP based Timer for how long the current is allowed to pass. It all happens quickly.

A (2) Terminal Electronic Flasher will work fine. Even with standard bulbs, but is a MUST for LEDS. (LED Circuits will also need other changes but don't go there right now.)
Let's just try to get your flashers flashing.
 
  • Like
Reactions: MDM
1 - 4 of 4 Posts
Top