Blowing Flasher Relay

[Simcard]

Hey all,

Got an issue with my 1975 xs650 kick start only bike. I rewired the bike with better connectors over the winter. Took it for 2 or 3 short rides this spring, then on the fourth ride my blinkers stopped working. Pulled the flasher relay and put in a new 2 prong Sparck Moto universal one and everything worked great. Thought problem had been fixed. Apparently I was wrong cause when I took the bike out again, checked that the blinkers were working while the bike warmed up, they stopped working at the second street I turned my blinker on for. Went back to the house and sure enough, the new flasher relay was blown.

I am glad all I am blowing is the flasher relay but what could cause that to blow but not anything else or any of my fuses? Scratching my head as to where to start checking things. Any ideas??? One thought I had was a grounding issue with the blinker system. Is there a "correct" way to ground the blinker system? Right now I believe I am grounding them on their own circuit separate from the other components. I will have to double check that though.

After rewiring the bike, the volt meter I am running off of the ignition switch shows about 15 volts when I am riding which seems high to me. Seems like the new bullet connectors are working better but I am afraid I might be over charging the system. Also after the rewiring, my idle dips when I turn on the headlight and goes up slightly when I turn it off. Not an electrician so please chime in if these are common things or red flags.

Attached is my current wiring diagram. Flashers are incandescent bulbs and I am using the 2 prong Sparck Moto universal flasher relay.

Thanks for all the help everyone!

 

[Its been a long time]

15v sounds high. If using the original regulator, they can be adjusted. Details in the Yamaha shop manual about testing and setting it up.

 

[Simcard]

I thought it sounded high. Thanks for the confirmation. The regulator is a Standard Motor Products VR115 so not sure if it can be adjusted or not. I will see about testing it to see how it is performing. I feel like I remember reading a thread on charging system checks where it talks about how to test the regulator. Seems like I might need to see what I am actually getting charge wise at the battery and compare that to what the volt gauge off the ignition switch is saying.

 

[Its been a long time]

I thought it sounded high. Thanks for the confirmation. The regulator is a Standard Motor Products VR115 so not sure if it can be adjusted or not. I will see about testing it to see how it is performing. I feel like I remember reading a thread on charging system checks where it talks about how to test the regulator. Seems like I might need to see what I am actually getting charge wise at the battery and compare that to what the volt gauge off the ignition switch is saying.

I don't know the VR115, they aren't really available in the UK. For reference, my Lucas regulator controls at 14.4 to 14.5v with lights off, around 13.5v with lights on. That's measured on a brown switched live wire.

 

[Simcard]

Finally had some time to get some readings. With the bike running and at around 3K rpms I get 14.3 at the battery. I then put in a short wire in place of the flasher relay and when I do the same thing but turn the blinker on, my voltage at the battery spikes up to 15-15.2 for a few seconds and then drops back down to 14.3. It seem that is my problem. Any thoughts on why that might be happening when the blinker is engaged? All my grounds for the blinkers run together and then back to a post next to the battery. All my other grounds go to a separate post.

 

[Wingedwheel]

Are you using the stock controls on your bars?

 

[Jan_P]

The High Voltage I believe is a regulator malfunction ..
And it can upset the Boyer
I would check the Regulator connections and Possibly pull the ground all the way to minus on the battery --se if that
changes things
After that I I would try another regulator .I have spare at home and they are not so expensive the Bosch 3 pin i Use

 

[Simcard]

@Wingedwheel I am using the stock controls on the bars.

@Jan_P The regulator is new so hoping it isn't bad. I will recheck all my wiring to and from it to make sure everything is solid (would be nice if that is the issue). When you say pull the ground to minus on the battery, what do you mean? Also, what Bosch regulator do you use? Thinking I may just swap things to a reg/rec from sparck moto if I have to replace the regulator.

 

[Jan_P]

@Wingedwheel I am using the stock controls on the bars.

@Jan_P The regulator is new so hoping it isn't bad. I will recheck all my wiring to and from it to make sure everything is solid (would be nice if that is the issue). When you say pull the ground to minus on the battery, what do you mean? Also, what Bosch regulator do you use? Thinking I may just swap things to a reg/rec from sparck moto if I have to replace the regulator.

This is How I think
The regulator is keeping the voltage within limits and the new electronic ones are good on that
so getting over 14.4 at any time is an indication of the regulator not getting the correct input or being defect.
It senses the difference between + and - Preferably across the battery

What can happen is that the + to the regulator has a voltage drop .So the regulator believe it is to low
the system voltage can be correct but the upside for the regulator have a drop sensing below say 14.4 it then regulates up

The separate line to the minus on the battery is a trick i use
it guarantees that the ground is perfect which it not always is otherwise. It helps with ignition problems also
One can measure Voltage in and with that extra ground it is correct both on upside and downside.

the Bosch type regulator is very common here and was more so
looks as below sometimes they are black plastic
If you search for Bosch 3 pin regulator they come up
Sometimes can be bought over the Counter locally
Be careful with the connecting so it is right

As recommended here on the forum the separate Regulator and Rectifier is better than a combo
of sometimes bad quality.
The auto parts have a higher rating and are used by many Car brands --aftermarket ones can cost around
$ 10 $ 15

having a spare at home is a quick way to plugin and get the answer if the regulator is ok
Saving faultfinding time

But getting over 14.4 with a new regulator I would suspect the connections

 

[AUTOMAN]

does anyone know how flashers work?
electo-mechanical
electronic

 

[Runninlean]

Do you have led turn lights?

Og flashers are mechanical mechanisms
LED lights take less bolts and will fry your regulator

 

[Jan_P]

does anyone know how flashers work?
electo-mechanical
electronic

Not sure and never checked
Guessing the mechanical it is like the old type door bell -- closing the circuit an electromagnet pulling the arm that is spring loaded
after the pull of the arm it opens the circuit spring pulls the hammer or what it can be called toward the bell ... plong ...
Closing the circuit ..repeat
power down stops

Electronic i know even less about but the closing and opening switch perhaps a Transistor
and components for the time open and closed

 

[AUTOMAN]

Not sure and never checked
Guessing the mechanical it is like the old type door bell -- closing the circuit an electromagnet pulling the arm that is spring loaded
after the pull of the arm it opens the circuit spring pulls the hammer or what it can be called toward the bell ... plong ...
Closing the circuit ..repeat
power down stops

Electronic i know even less about but the closing and opening switch perhaps a Transistor
and components for the time open and closed

nope, i thought not

 

[Wingedwheel]

nope, i thought not

So what’s the point of the question?

 

[Simcard]

Checked my connections on the blinker grounds and to the regulator. Everything seemed good. Moved blinker ground to the negative on the battery. Started the bike, voltage checked out at 14.3. While at idle, turned blinker on and voltage dropped steadily to 13.3 or so. I then revved bike to 3k, turned blinker on, and voltage jumped to 15 and then the fuse blew on the blinker circuit. Seems moving the ground didn't help the issue. I will check over all my connections on the bike and try moving all my grounds to the negative battery terminal and see what happens. Hopefully that will illuminate the issue.

P.s. blinkers are not LEDs but incandescent bulbs. Have considered moving to LEDs as they draw much less power but I like the look of these blinkers (turn signals from Dime City)

 

[Simcard]

Just had a random thought, I do have each blinker going to a LED light on my speedo gauge to show me if the blinker is on or not. Have it tied in using Sparck Moto's LED diode kit. So blinkers are incandescent with one LED in the gauge. The gauge LED is then grounded with the rest of the blinker lights. Updated the wiring schematic to better show how I have things grounded.

 

[Wingedwheel]

Maybe I’m looking at this wrong but when fuses blow I look for a short, a nicked wire, bad component, something. Would a current draw create the charging spike?

 

[AUTOMAN]

If current drags the voltage down, then suddenly current goes down, voltage spikes and then comes down. Takes a few seconds.

Looking at schematic, for thermal/electric flashers the left front/rear bulbs take current via the l/r switch. The switch gets the current from the flasher via fusebox.
IT IS this current draw that makes the flasher heat-up, bending the bimetallic arm and break the current flow.
This arm in the flasher then cools down and makes connection again. Repeat every 1/2 to 1 second. Click click click.
More current = faster clicks
Too big of a bulb = faster clicks
1 Burned out bulb = slower clicks
LEDs = no clicks(not enough current to heat the flasher arm)

What is a blinker ground? other than the turn signal bulbs?

 

[AUTOMAN]

Think of the original flasher as a self-resetting circuit breaker.
Enough current and it breaks(the breaker part of a circuit breaker)
These flashers are designed to trip with a couple of 21w lites "shorting them"
Regardless of voltage from battery up to 18-20+ volts.

Do the blinks/winks come on then goes out when the blinker switch is turned to left/right?


Electronic flasher is just a timer that works from 6-22 volts.

Both, control the current to the blinks/winks.

Blowing flashers is dead short on wire(s) from the flasher left/right/rear or front.
This welds the points/or output transistor inside of the flasher or just melts.

 

[Simcard]

I believe I found the issue. Bulb inside the blinker was some how stuck down in the future and was grounding against the side of the blinker housing. Must have hit a bump or two just right Took the bulb out, put it back in correctly, and everything works like it should. Have to start it up this weekend and double check voltage at the battery but I'm pretty confident that was the issue.

Thoughts on using a smaller fuse, say 5A or 7.5A instead of a 10A, so as to hopefully blow the fuse rather than the flasher relay in the future?

Appreciate all the help everyone! Hearing that it sounded like a shorting issue got me on the right path!