I have fitted indicators to my 1970 Stafire using the existing wires that are in the original wiring harnes, all 4 indictors have seperate earth leads. when the lights are on and I operate the indicators the rear light and also the stop light also flash but not in sync with the indicators. Could this be an earthing problem with the rear light and stop light. Thanks.
Highly likely an earth problem.
Ensure each indicator stalk or body is earthed well before going deeper.
A simple trick is rig up a long wire, clamp to a good earth and dab it onto each indicator to see which one is the culprit.
Thanks for that info, I have run seperate earths for the indicators, I connected the 2 front earth wires together then ran a single wire from them to earth did the same for the rear indictors, have created I think what is termed a star earth system so all earths go to one point. But the orignal lights do not have seperate earths they are as they left the factory.
Quote from: bikerbob on 02 May, 2024, 15:45
I have fitted indicators to my 1970 Stafire using the existing wires that are in the original wiring harnes, all 4 indictors have seperate earth leads. when the lights are on and I operate the indicators the rear light and also the stop light also flash but not in sync with the indicators. Could this be an earthing problem with the rear light and stop light. Thanks.
I'm not quite following what you mean. Do the stop light and tail light flash with the indicators even when they themselves are not lit? Or do they vary in brightness when the indicators are operating?
If the first case it's an earthing issue. If the second it's a high resistance somewhere in the supply side.
As long as the earth point that you have created at the front runs via a wire back to the main frame earth and not rely upon the headlamp earth.
Many British bikes relied upon the head bearings to carry the earth from frame to front end.
The rear lights would rely on the quality of their earth connection to the rear mudguard.
Hence the suggestion to have a long earth wire to provide a known good earth to the rear light unit
Just to clarify I ran seperate earth wires front and back into 2- 4 way bullet connectors then a wire from each connector to a central point that is earthed to the frame under the seat, this point is also the connecting point for the battery earth. Without the engine running ignition on indicators work fine, switch pilot lights on indicators still work but slow down slightly both rear light and stop light flashing . Switch headlight on and indicators really slow down and rear lights flashing. With engine running everything works OK with pilot and headlight on except rear lights flashing. I believe the battery is OK because it holds charge for at least 2 months while standing during winter lay up at the moment it is showing 12.5 volts with noothing switched on. The only reason I used the 4way connectors instead of 3 way connectors is because I did not have to hand any 3 way connectors all bullet connectors are soldered.
It's due to a voltage drop in the supply. I've come across this previously, on an elderly BMW and a Ducati 907ie. In both cases it was caused by poor contacts within the ignition switch causing a voltage drop of over 1V when the headlights were switched on. The voltage would drop further every time the indicators lit up, causing the tail light to pulse along with the indicators.
I remember it well with Fords of the 1970s. Lousy earths, every time.
Thanks for the replies, I have just spent the last couple of hours removing the rear light fittings, have run a seperate earth wire soldered to the bulb holder and connected to my central earthpoint on the frame. It has made no difference have checked the voltage at the battery it is showing 12.4 volts, with the lights on the voltage at the rear light bulb and stop light is 11.97volts. Voltage at the battery with sidelights on 12.09 volts, voltage with head light on 11.41. Do not know if is relevant or not but when the head light is on the pilot light stays on I should have thought that it should go out.
As a matter of interest, what is the voltage across the battery with engine running at a decent/fast tickover?
Should be around 13.9 or 14v
Then keep the engine running and try your indicators only, should be a nice steady on/off 1 every second.
Establish firstly that they're OK, then turn your lights on pilot then head, all the time with engine running and a decent voltage at the battery
your leaking somewhere. As others have said up to 14v is what your looking for. Anything less than 12v indicates a duff battery I think. Soldering as you have done is a sure way to get a good connection as I find bullet connections, especially when wet will partially fail. Soldering rectifies this. Only a small amount of corrosion will effect an earth connection. I had exactly the same problem with an old VW camper which seem to be wired in a similar way to British bikes. It turned out to be corrosion on the earth and when I found and corrected it, everything worked fine.
It seems like the battery is struggling; it may be that fitting the indicators has just shown this up. So here's some questions: How many amps is your battery rated at, and what is the total load on the battery (watts or amps) with the headlight on? What is the wattage of your indicators? Is 12.4 volts the battery voltage with everything switched off?
Everything you've done so far, though it hasn't solved the problem is still worth doing, just for future reliability.
Thanks for the help I am struggling with a heavy cold at the moment so have not been able to get back to the bike, but hopefully I am on the mend and will get back to the bike later in the week and will do all that has been suggested will keep you updated later in the week Thanks again.
Apologies for not getting back sooner but I ended up as an emergency admmission to hospital and have been out for a couple of days. Update I have fitted a new battery which is the correct replacement for the original battery, the battery that came with the bike was not the right size. However with the headlight on the indicators do not now slow down when flashing but the lights still flicker so over the weekend I am going to fit a seperate earth for the front lights as I have fitted a seperate earth to the rear lights. will see if that works.
Without the engine running(and thereby charging) the headlight will dim a bit as the indicators come on and off.
This is normal.
I think I mentioned way back in this topic to test it with the engine running (at an imaginary 30mph engine speed) and try your indicators and lights then.
If you have a meter to put across the battery even better.
Around 14volts engine running and no lights or winkers
Around 13.5 ish with lights and winkers , give or take
Started the engine without anything on normal tickover 13.5 volts at the battery increase tickover and it goes to about 14.6 volts. with lights and indicators on can still get above 14 volts with fast tickover but lights still flickering. Had a look inside the headlight and the earth for the lights is a spade connection on the headlight switch that connects to a 4-way bullet connector then to headlight and pilot bulb holders. When I get some more time I will run a temporary earth wire from that spade connector to a point on the frame and see if that changes anything because it looks as though that earth on the switch earths through the switch to the headlight shell.
Ok , so you're charging fine
When you say lights flickering, are we talking of both front and rear lights rhythmic fluctuation in time with the indicators ? Or random bad connection type flickering, not in time with the indicators?
Can we assume that your indicator is a 4 x 21watt (front 21 and rear 21 each side ) or are they 10watt indicator bulbs.
If you think about it, your headlight bulb is probably 45 Watts or thereabouts , your pilot is 6 w and the tail is 6w.
You turn on left or right indicators and you have another 42watts , so there is quite a draw. On the system
Have done those tests and everything checks out OK with a multimeter. They are 21 watt bulbs in the indicators and do flicker in time with indicators both front and rear with or without the engine running. Have run a seperate earth wire from the front lights to my central earth point on the frame makes no difference. So the battery is not the problem the charging system is OK and the earths are all OK am getting correct voltage readings for the lights just over 12 volts also for the indicators. Have been doing a bit of research on the web and found that someone with a modern bike a suzuki I think had a similar problem lights flickering in time to the indicators traced the problem to a faulty flasher relay replaced relay problem solved. My relay is a new relay but it won't be the first time I have bought something new that did not work they are not expensive so to eliminate that I will order a new one and see what happens will let you know when fitted. Thanks again for your help.
I suspect your problem may be in the supply side rather than an earth issue. With the lights on measure your voltage across the battery terminals and compare it with voltage between the battery +ve (earth) terminal and the light switch. There should be negligible difference. You can also check the resistance between the battery -ve terminal and the light switch or better still the supply connection at the taillight. The resistance should be very low, preferably less than 1Ω.
I have done the voltage test and there is about half a volt difference. Have tried to do the resistance test but I must be doing something wrong because no matter what ohm setting I use on the multimeter I can get no readings at all.
Quote from: bikerbob on 21 May, 2024, 08:08
I have done the voltage test and there is about half a volt difference. Have tried to do the resistance test but I must be doing something wrong because no matter what ohm setting I use on the multimeter I can get no readings at all.
I should have said to disconnect the battery and that that lights should be switched on or obviously there will be no continuity between the battery -Ve connection and the tail light. Half a volt is a fair drop and it will drop further when any additional load is applied which would explain why the light brightness varies with the indicators flashing.
Thanks for that info but the bike is going to have to take second place for a while as wife rushed into hospital yesterday when I can get back to it I will start a new topic and update my findings. Thanks.