Topic: Turn signals light but won't flash

[brewsky]

550K3

Turn signals quit working before I replaced them.

Replaced them with a new set with stock wattage bulbs.

They light up when switch is turned, but won't flash, even with new (thermal) flasher.

The buzzer is missing, but they were previously working without it.

They light up even when the flasher is removed Don't they get their hot 12v thru the flasher?

Does this mean they are getting 12v bleeding in from somewhere else?

Signals are grounded direct to green harness wire as they are rubber mounted.

Same condition with front running lights connected or not.

The correct wires are connected to the correct filaments.

Adding an extra 12.6v battery source to the black flasher terminal (with flasher installed) .......no change.

I'm guessing its down to frame ground or switch defect?

[johnny]

Had a similar issue with my 550 recently. The culprit was a bad ground wire in the right turn signal. I ended up replacing the wiring / bulb assemble (because it was a cheap aftermarket turn signal) and it works fine now.

[wardenerd]

sounds like the ground to me too.  Both my bikes have ground wires to the stem screws.  solved my problem

[Sdsbassist]

+1

[Sitarz84]

I have a 77 CB750f and my signals dont flash. Where exactly is the relay located. What do you mean when you say the problem is the ground? Does that mean is not grounded or that the ground was shorted to something?

[flybox1]

all signal lights have a hot and a ground. 
probably black and green, respectively, if they are not aftermarket signals.
the ground connects to some part of the headlight bucket, frame, or signal stem.  follow the ground from the bulb, and make sure it is not corroded or loose. connect it to a clean spot.

[brewsky]

Am I wrong thinking the flasher completes the circuit (and opens it to flash)?

[lucky]

Am I wrong thinking the flasher completes the circuit (and opens it to flash)?

You are correct.

Bulb--------flasher---------12V

On the CB750 there is a grey wire that goes from the flasher to the left handle bar switch.. that grey wire is 12V from the flasher. When you slide the switch from either the left or right signals it contacts the grey wire contact in the switch.
the

[Bodi]

The flasher is connected to "ignition" (switch on) power  fthen the flasher output connects to the switchpod signal switch (grey wire) When you activaet the switch and a lamp load is connected the flasher is on at first then starts to flash off-on-off-on. That's with an electromechanical flasher like the OEM one. Two-terminal electronic flashers are off at fist then flash on, 3-terminal electronic flashers start on the flash off.
I don't quite see how the signal lights would work without the flasher if the flasher is removed  - unless the flasher switch is connected to a black ignition power wire instead of the grey flasher wire. Possibly power could flow through the marker filament and do some weird things if the sockets are not grounded though.

[Sitarz84]

Am I wrong thinking the flasher completes the circuit (and opens it to flash)?

You are correct.

Bulb--------flasher---------12V

On the CB750 there is a grey wire that goes from the flasher to the left handle bar switch.. that grey wire is 12V from the flasher. When you slide the switch from either the left or right signals it contacts the grey wire contact in the switch.
the

My bike does the same thing. Its a 77 750 and when i hit the turn signals the lights illuminate as they should but there is no flashing. If power must go through the relay to turn the light on I think that the problem could be in the relay and the relay is stuck in a closed position.
If a light bulb in your house stays on no matter what position the switch is in then its a bad switch. The same might go for the relay

[brewsky]

The proper bulbs come on when the switch is moved L or R, but they just don't flash.

The same thing happens when the flasher is completely removed from the bike.

This means the bulbs are getting their current from somewhere other than the grey lead from the flasher.

Hopefully it is just some switched wires in the headlight bucket. If the buzzer lead got connected to a black, that would probably do it if I'm reading the wiring diagram right.

The inside of the switch doesn't appear to be the problem, as its well greased and no oxidation evident.

I ran a completely separate ground with no change.

So its back into the bucket.........

[brewsky]

Bingo!!
1. Bad flasher.....that's why they quit working before I replaced the turn signal set.

2. Brown/Blue buzzer lead (buzzer is long gone) was plugged into the empty socket for another Brown /Blue wire from the tail light fuse.
(That's why they didn't work after new signal were installed and also why they would still light even after the flasher was removed.)

Since the Brown/Blue buzzer lead is connected to the Orange or Blue turn signal leads when the switch is activated, that is why the signals only came on (and didn't flash) when the switch was avtivated.

Good thing I made notes of the connections in the bucket before I un did all of them......bad thing that I didn't use the notes to re-connect everything!!!

Moral.....just because it looks like 2 wires should connect based on color doesn't mean they should.

Note that the one wire is a brown/light blue and the other is a brown/blue, the color differences are not distinguished in the wiring diagram, and are definately hard to distinguish in the bucket.

[Sitarz84]

where is the flasher located? I'm having the same problem with my bike

[LesterPiglet]

The relay lives under the left panel with the rest of the electrical gubbins.
The wire you mixed up has a tube on it to distinguish it from the other of the same colour.

[brewsky]

The wire you mixed up has a tube on it to distinguish it from the other of the same colour.

Indeed it does!....and I completely missed that, as it was lurking under the socket cover in the darkness!

[Sitarz84]

any way I could get a picture of what the flasher looks like and the tube that distiguishes itself from the others?
I'm sure it would help out a lot.
So given that I have the same problem what should I be looking for first?

[LesterPiglet]

The relay on mine looked like this http://www.1977mopeds.com/product/682/Tomos-Flasher-Relay/ but I changed it to a new electronic one that is black plastic and square, similar to this  http://nbboss.en.made-in-china.com/offer/LefxoEpAFgWr/Sell-Auto-Flasher-Relay.html

These are just for reference, they may not be suitable. I only looked for pictures.
The tube on the wire is yellow I think and it is at the connector. It's only short.

[Sitarz84]

The relay on mine looked like this http://www.1977mopeds.com/product/682/Tomos-Flasher-Relay/ but I changed it to a new electronic one that is black plastic and square, similar to this  http://nbboss.en.made-in-china.com/offer/LefxoEpAFgWr/Sell-Auto-Flasher-Relay.html

These are just for reference, they may not be suitable. I only looked for pictures.
The tube on the wire is yellow I think and it is at the connector. It's only short.

awesome thanks....i'll be looking for that after work

[brewsky]

Here's a pic of the flasher on a 550, round one is the generic replacement from auto parts store, and the square one is OEM.

The wire to the buzzer on mine has no band and is brown with a blue stripe. If you still have the buzzer, you may not have the same problem as me.

If the buzzer is gone, just make sure the wire is not connected to anything.

To see if you have 12v from another source like I did, simply remove your flasher completely and then try the signals. If they still light up but don't flash, you probably have the same problem. If they don't light up at all, then it's another problem.

[LesterPiglet]

Hmm, mine was originally round.

[brewsky]

Hmm, mine was originally round.

Interesting.....I'm just assuming my old one was oem, it might not be.
The rubber hanger for it is definately square and fits the one that was in there.

[LesterPiglet]

And my rubber hanger is round....go figure.  I think mine was original as I got the bike when it was 9yo.

[LanceT847]

This thread has the most information I could find on the net. My bike would light the signals with the switch but not blink. So I bought a new 142 stat flasher and the same thing. I went through the wiring and it all looked right. put a 2nd new flasher in and  Whamo! Problem solved. It took 2 new flashers and a day of dinking around but I got it

[oldhatt45]

Just a little FYI on the Flasher.  I just replaced the Original Flasher (Signal Stat 142) on my CB750.  The original Signal Stat is listed at about $24.00 on a couple of web sites.

The local Advanced Auto Parts Store has the DOT #552 Flasher which is a 2 wire Thermal Flasher for $3.99.  They work fine.

Advance Auto also has some Electronic Flashers as well.  I also bought one of them an EP34, but it is 3 wire.  On my 750, I had a loose Green (ground) wire in the location of the flasher (just behind the battery tray).  Used the 2 Original wires, White (= to lamps), Black ( = to 12v power) and then connected the Green ( = Ground) to the Negative terminal on the electronic flasher. 

Works like a charm.

Charlie

[BomberMann650]

reading this thread makes me think thats whats causing my bike  to melt thermal flashers and blow main fuses.

my arms work perfectly fine otherwise.