1992 R80GS PD = switched live, without ignition interruption?

No click.
Bad relay? Looks new, was in a box of spare bits I have, but unknown origin .
also what numbers do you have on the base ??

test it off the battery as you know it is charged

you can just test the connection across the 85 86 to see if it clicks then?
 
I've now tested using a 12v relay (and get a click), the Acewell powers on with ignition as expected and STILL REBOOTS ON STARTER PRESS.
So, even using a dedicated relay circuit, the Acewell reboots - surely this must be either an Acewell issue where the slightest drop in voltage causes a reboot (by design?) or I do have a duff battery which is undersupplying enough for the Acewell to reboot, when the starter motor sucks juice from the battery
 
I've now tested using a 12v relay (and get a click), the Acewell powers on with ignition as expected and STILL REBOOTS ON STARTER PRESS.
So, even using a dedicated relay circuit, the Acewell reboots - surely this must be either an Acewell issue where the slightest drop in voltage causes a reboot (by design?) or I do have a duff battery which is undersupplying enough for the Acewell to reboot, when the starter motor sucks juice from the battery
Just connect the Acewell "switched live" to a known good battery Miss out all other connections

What is the result then?
 
Just connect the Acewell "switched live" to a known good battery Miss out all other connections

What is the result then?
My known good batteries are the one's on my bikes, it's getting to the point where I admit temporary defeat, then regroup when my current battery actually expires and counter-attack the Acewell assault with a brand new battery.
 
My known good batteries are the one's on my bikes, it's getting to the point where I admit temporary defeat, then regroup when my current battery actually expires and counter-attack the Acewell assault with a brand new battery.
Is one of the others easily removed ??

Or can you get near your car and run a jumper lead from the car to the switched live ??

That would eliminate the Bike and show a fault with the Acewell

OR

as mentioned the starter motor may have a loose magnet causing a higher current drain
 
You're absolutely right - my method was WRONG!
The green wire to the coil, when feeding the Acewell speedo, causes a reboot on starter button press.
HOWEVER, feeding a bulb from that green wire and ground direct to battery causes the bulb to DIM, but stay lit!
Volts drop to about 9v on that wire on my voltmeter.

It is my interpretation that the earlier suggestion of a substantial enough drop from the battery, that is not enough to turn off the bulb, but enough to cause the Acewell to reboot is the issue.
Implying that my otherwise fine seeming battery, may not be providing enough power to any circuit(!) for the Acewell to stay on when the start button is pressed.

BUT, if the interpretation above is correct, how is there enough power to crank the engine and start the bike without hesitation - every time!?
Am I misunderstanding the starter motor supply - is that by design, isolated from the other circuits and unaffected by the voltage drop?
It seems peculiar otherwise that I always have enough juice to crank the engine, but not enough to keep the Acewell powered on. The latter requiring a tiny amount of supply vs the former.
The electrical load of the starter motor is taken by a big thick red cable permanently connected to the positive terminal of the battery and the 8mm thread stud (13mm nut) on your starter motor solenoid. The starter when running earths through its bolted connection to the engine block. The starter motor, if a bit worn out or otherwise inefficient, will cause a greater voltage drop than normal. If the big thick cable I mentioned is 32 years old it could have built up an internal resistance which will also rob the starter circuit of volts. The whole design is fairly forgiving in that if the ignition circuit is also of original design it will supply sparks to a slow-turning engine on the starter and if the fuel side of things is also ‘good’ then the engine will start.

In your case, all this happens at 9V as you have measured. The voltage drop is caused by the starter - not by the load shedding relay or any other circuit on the bike. Your green wire will still work (supply voltage to create a spark) at 9V but not as efficiently as it would do at higher voltages.

Sorry if this is ‘teaching granny to suck eggs’.

My only suggestion to keep your Acewell alive during starting is to wire in a separate 12V supply that is not affected by the starter, that is, not connected to the bike without a diode or a relay or some other method. The diode/whatever should stop the small 12V supply from adding to the starter supply.
 
The electrical load of the starter motor is taken by a big thick red cable permanently connected to the positive terminal of the battery and the 8mm thread stud (13mm nut) on your starter motor solenoid. The starter when running earths through its bolted connection to the engine block. The starter motor, if a bit worn out or otherwise inefficient, will cause a greater voltage drop than normal. If the big thick cable I mentioned is 32 years old it could have built up an internal resistance which will also rob the starter circuit of volts. The whole design is fairly forgiving in that if the ignition circuit is also of original design it will supply sparks to a slow-turning engine on the starter and if the fuel side of things is also ‘good’ then the engine will start.

In your case, all this happens at 9V as you have measured. The voltage drop is caused by the starter - not by the load shedding relay or any other circuit on the bike. Your green wire will still work (supply voltage to create a spark) at 9V but not as efficiently as it would do at higher voltages.

Sorry if this is ‘teaching granny to suck eggs’.

My only suggestion to keep your Acewell alive during starting is to wire in a separate 12V supply that is not affected by the starter, that is, not connected to the bike without a diode or a relay or some other method. The diode/whatever should stop the small 12V supply from adding to the starter supply.
This granny is grateful for the lesson.
I have learned a great deal about my Airhead (and general motorcycle) electrical system from all of the generous input here.
It's much appreciated and equips me with improved ability to troubleshoot.
I've actually started to enjoy wiring work instead of fearing it.
 


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