Topic: Cb400f flasher not working.

[soonerbillz]

My 76 cb400f I have been working on has some electrical gremlins.
 First question is about the flasher. The turns come on but do not flash.
 I had looked at the manual electrical schematic and it says the flasher ahold be a 3 prong connection with a grey wire, a black wire and a dark green wire. Both the 4-1 diagram and the factory schematic shows it to be a three prong.
 Mine as the pics I loaded show ics a 2 prong flasher. Only the black and grey leads are attached.
So first off: is that flasher correct or not?
 Second I asked previously about that dark green wire and was told it was an extra power wire??
Finally what is the part number for the correct flasher for me to order?
 Thanks

[Sw1ssdude]

Black is switched plus. grey is the indicator signal, the intermittent on-off voltage (which will be directed to either light blue or orange in the indicator switch, the turn signal wire colors for left and right). green is ground.

Some flashers dont need an extra ground, some do. depending on how they work:

some flashers have a bimetallic strip inside, which gets hot under load, bends, and opens the circuit. as it cools down, it bends back, closing the circuit and starts heating up again. these very basic (and oldstyle) flashers mostly even work when connected incorrect, but they hardly ever work, as they are very sensitive to heat, vibration and other environmental influence.

Some have magnetic coils inside, which open and close the circuit. they create their delays with clever circuitry, and coils and capacitors. they often rely on proper grounding. and the correct load current: as soon as one of your bulbs goes out, the load splits in half, and the switching frequency doubles. they have to be connected correctly: X or B is for the switched plus, L (for Load) is for grey. Ground might be E (Earth).

very new electronic flashers dont care about the load or tension, they just take a steady input voltage, apply a lot of science to it, and deliver a choppy output voltage (usually with minimal energy consumption, delivering all the precious current to the bulbs, unlike the other electromechanical flashers). the electromechanical ones consume a considerable amount of the current which was destined to go to your bulbs.

make sure your flasher is rated for 12 volts (not 6, for small or very old bikes), other than that, you cant go wrong.

[Flyin900]

If you can read your colour schematic it clearly shows the green wire as a ground which it always is on 70's and 80's + Honda bikes. Back in the earlier 1960's there were some Honda switchgear that did use a green as a 12V + on the lighting circuit only. The two wires ( grey and black) should be correct to supply the relay correctly. Most of the small flashers were 2 wire only and that extra green ground wire was unused on NA bikes as I recall.

The flasher could be pooched being original, or you may also have ground issues with the signal posts mounting and grounding to the frame or headlight ears. This will also cause the signal lights to light, but not flash correctly.

That flasher is a bimetal design, so the heat generated when in service causes the contact metal to open and close in a heating a cooling cycle on the signal lights.

To get proper parts numbers... look those up yourself on a parts fiche with the model and year of your bike. Easy peasy once you have the website stored in a app on your device.

[Don R]

 They are voltage sensitive, try it with the engine revving or a trickle charger connected. I had a 76F that always told me if the battery was low by the squeaky turn signal beeper and slow flashing.

[Bodi]

That might be an original flasher, definitely fits in the rubber mount. But I would expect a Japanese brand like Denso, not Signal Stat.
Anyway - these work via the lamp current which heats up the inside and makes it turn off. Then with no current it cools down, turns on... repeats.
The green wire is ground for a 3 terminal flasher, maybe used in different markets.
Since they work on the current from 2 normal bulbs - if you use LED signals it won't flash.
And they do fail. Pretty much any 2 terminal automotive flasher will work. For LEDs there are special LED flashers, some 3 terminal automotive ones are OK, or you can add load resistors that draw the current that normal bulbs would.

[Kevin D]

My 71 cb750 k1 has a Signal Stat 142. Sorry I can’t remember if it’s original, but likely it is.
Recently I learned a lesson about a simple thing with turn signal bulbs this: you need the correct bulbs. A 1073 bulb and it’s 23 watts is not an 1156 bulb with its 27 watts, and two 1073 bulbs will not flash a signal stat 142 flasher. A 1073 + 1156 will give a very slow flash. Two 1156’s have a proper flash rate.

[bryanj]

A lot of japanese bulbs are rated in cp(candle power) NOT watts

[CB400Finhawaii]

I have a 1975 CB400F and had he same problem.  Blinkers would go on, but not blink.  I checked that power was getting to the relay, and it was.

I have the gray and black leads, with the green wire not connected to anything.  I replaced the flasher relay and it works fine now.  I ended up buying my flasher relay from 4into1.com because I was ordering other stuff from them anyway.

[Bodi]

There's no magic and it's a super simple circuit.
If you switch a signal on and both front and rears light, both directions, the wiring is good.
The switch gets power from the grey wire. The flasher module connects black (key on battery power) to the grey wire.
So if the wiring is good... problem is the flasher.
The electromechanical ones can wear out. "Electronic" ones can fail.
If you have LED signals or use low wattage bulbs (don't! you want them bright!) the OEM flasher and other electromechanical ones will either not flash at all or flash slowly, or really weirdly slow: short flashes off with a pretty long on wait in between.
Best bet is an electronic 3 terminal flasher. Like a Tridon EP32 or equivalent. This is for normal bulbs and will do a fast flash with a burnt out bulb or with LED signals. There are LED types that will flash the "normal" slow speed but I like the fast LED flash anyway.
Two terminal electronic ones will start "off", then flash on. Three terminal types start on and flash off... I don't like the delay after signalling so I don't use two terminal ones. The green wire is hanging there specifically for three terminal flashers. Be aware that there are several types of three terminal ones and some have two outputs and no ground... just a one shot fuse tester if you try one of them. You want one with E, B, L terminals or the DIN 72552 numbers 31, 87, 87a (I think).

[newday777]

My 76 cb400f I have been working on has some electrical gremlins.
 First question is about the flasher. The turns come on but do not flash.
 I had looked at the manual electrical schematic and it says the flasher ahold be a 3 prong connection with a grey wire, a black wire and a dark green wire. Both the 4-1 diagram and the factory schematic shows it to be a three prong.
 Mine as the pics I loaded show ics a 2 prong flasher. Only the black and grey leads are attached.
So first off: is that flasher correct or not?
 Second I asked previously about that dark green wire and was told it was an extra power wire??
Finally what is the part number for the correct flasher for me to order?
 Thanks

Bill, you haven't replied back on this thread you posted almost a month ago now....... what did you do on it??
You mentioned a "4-1 diagram", what is that??

1st off, the 142 flasher is the correct 2 prong from the factory for the US models Bill. It has died on yours and needs to be replaced.
2nd. The dark green is always ground on the Hondas. It was always there in case someone wanted to change to a 3 prong flasher. Power is never green on Hondas from the factory. A 3 prong flasher is not necessary on these bikes.

As others have said,  get a new flasher. There are several available electronic flashers available that will work with either incandescent bulbs or LED bulbs, or a combination of both incandescent and LED  bulbs. They are always bigger than the 142 stock flasher so you have to be creative with mounting them in the same location or to use the rubber mounting flasher holder.
The 142 stock flasher can only work properly, with correct flash rate, using incandescent bulbs as in is a thermal flasher. If you are trying to keep your bike 100% original (you didn't say???) You can order a 142 from Honda.

[newday777]

This electronic flasher from 4into1.com should work and is a 2 prong flasher to replace the 142 flasher.

https://4into1.com/12v-electronic-turn-signal-flasher-relay-led-2-prong/

[Flyin900]

This poster asks questions then never responds to the suggestions offered. If you look at his other posts the same “crickets” non response.

This unfortunately doesn’t help anyone with the same issue for future reference to trouble shoot and have a solution to the problem. 

[soonerbillz]

Again sorry for the late reply.
 I had ordered a new flasher and a new rear brake switch plus a new rear tail light socket.
 The brake lights are working correctly now.
 The installation of the new flasher did not solve the flasher question.
 So after much hair pulling and going g through everything wiring several times it turned out to be a ground issue. One the system was fully grounded to the bulb socket the flashers started working properly.
 Thank you guys for all the help.

[newday777]

Again sorry for the late reply.
 I had ordered a new flasher and a new rear brake switch plus a new rear tail light socket.
 The brake lights are working correctly now.
 The installation of the new flasher did not solve the flasher question.
 So after much hair pulling and going g through everything wiring several times it turned out to be a ground issue.

Once the system was fully grounded to the bulb socket the flashers started working properly.

 Thank you guys for all the help.

That'll do it.