I have mentioned in some of my posts that the electrical system ampere requirements are more important than the electrical system voltage requirement. I mention this because it is an accepted fact that the output from the alternator unit is expected to be maintained at ~14.0 VDC regardless of the electrical system load. It is the electrical system load in amperes that fluctuates and causes the RR to allow more or less current into the electrical system to maintain the voltage at ~14.0 VDC.
In this regard I purchased a clamp meter that measures direct current. Had one that I thought did but found out it only measured AC. The readings are an indication only and I do understand that the accuracy of my meter may not be up to that required by NASA, but I now have an appreciation for the ampere requirements of the system, and roughly how the load distribution is.
Measured the DC in the electrical system on my '85 LTD here in Victoria this afternoon. The key here is the voltage indicated on the dash voltmeter staying constant at ~14.0 VDC.
On start and with fast idle (1150ish RPMs) and 14.0 VDC display on the dash voltmeter: 17 amps
At fast idle and 14.0 VDC on dash voltmeter: fluctuate between 15.5 amps and 17 amps - indicates battery has been topped up
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights on: 20.5 amps
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights on and rad fan as well: 23.5 amps (have a manual switch for rad fan)
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights, rad fan, and heated clothing: 29.0 amps
Considering the alternator units on these bikes is capable of a max ampere output of approximately 35 amps, these readings indicate to me that there is more than enough power for the bike operation as designed and intended by the OEM without any additional loads added by the owner such as driving lights, and heated clothing.
The '85 LTD FI and '86 SEi FI bikes have a 30 amp circuit connected to the battery terminal of the starter solenoid. Took a reading from the wire to the starter solenoid and it displayed ~10.5 amps. Took a reading on the wire/cable from the starter solenoid to the battery it registered ~3.0 amps. This indicates to me that the battery is taking 3.0 amps and 7.5 amps are going back into the electrical system for bike operation, and that 7 amps are going into the electrical system through the ignition switch. I did another check of the amperage from the alternator and it was still at ~17 amps.
I think this reading to the starter solenoid is quite important from an understanding perspective. I have mentioned that I do not subscribe to the philosophy of connecting additional loads to the battery positive terminal. If the amperage going from the power junction to the starter solenoid at ~10.5 amps was connected to the positive terminal of the battery, the battery would be continually in an overcharging state even though there are other loads needing some of this power. It would be nice to think that the power would be discriminating and go to where it is needed and not affect any other component, but since there is no control over this the battery would be seeing more power than is intended.
I also connected my heated clothing into the electrical system. The heated liner increased the electrical system load by 5 to 6 amps – considerable actually.
Turned on the signal lights, and the electrical system current fluctuated approximately 1 amp - bounced around actually. Not to concerned because the signals are short duration use.
I have a 3 wire external alternator installed (55 amps) and it is more effective in reacting to the varying load demand than the OEM 3 piece alternator unit. You can see the current fluctuate ever so slightly 0.2 - 0.3 amps at idle and even when the engine RPM was increased to 2000 RPM.
I annotated a schematic with some arrows for current flow and letters for current at various locations. This schematic is when the engine is started and at idle.
Here is the schematic:
Point A is the one connection where the total electrical system load is represented. In the case of my bike at idle it is approximately 17 amps - good number to use.
Point D is approximately 10 amps of which this is split such that point C uses approximately 7 amps and point B (battery) uses approximately 3 amps. Point C is a 30 amp circuit that is connected to the starter solenoid battery terminal and is apparently only on the '85 and '86 FI models. This further indicates a best practice of not connecting directly to the battery positive terminal as there would be 10 amps at the battery instead of 3 amps - the short battery cable connection to the starter solenoid does do a specific design service. For those who do not want to do a lot of wiring change, a best practice of connecting extra circuit(s) at the the battery terminal of the starter solenoid should be preferred instead of at the battery positive terminal.
DC flow is reversed at point D when the electrical system voltage drops below battery voltage, but this expected to be for short period of time, not the norm. The DC flow will primarily be to the starter solenoid, not from it.
The remainder of the 17 amps at point A goes through the ignition switch at point E and is approximately 7 amps.
Thought I'd share some of my findings.
Cheers
In this regard I purchased a clamp meter that measures direct current. Had one that I thought did but found out it only measured AC. The readings are an indication only and I do understand that the accuracy of my meter may not be up to that required by NASA, but I now have an appreciation for the ampere requirements of the system, and roughly how the load distribution is.
Measured the DC in the electrical system on my '85 LTD here in Victoria this afternoon. The key here is the voltage indicated on the dash voltmeter staying constant at ~14.0 VDC.
On start and with fast idle (1150ish RPMs) and 14.0 VDC display on the dash voltmeter: 17 amps
At fast idle and 14.0 VDC on dash voltmeter: fluctuate between 15.5 amps and 17 amps - indicates battery has been topped up
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights on: 20.5 amps
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights on and rad fan as well: 23.5 amps (have a manual switch for rad fan)
At fast idle and 14.0 VDC on dash voltmeter with both sets of driving lights, rad fan, and heated clothing: 29.0 amps
Considering the alternator units on these bikes is capable of a max ampere output of approximately 35 amps, these readings indicate to me that there is more than enough power for the bike operation as designed and intended by the OEM without any additional loads added by the owner such as driving lights, and heated clothing.
The '85 LTD FI and '86 SEi FI bikes have a 30 amp circuit connected to the battery terminal of the starter solenoid. Took a reading from the wire to the starter solenoid and it displayed ~10.5 amps. Took a reading on the wire/cable from the starter solenoid to the battery it registered ~3.0 amps. This indicates to me that the battery is taking 3.0 amps and 7.5 amps are going back into the electrical system for bike operation, and that 7 amps are going into the electrical system through the ignition switch. I did another check of the amperage from the alternator and it was still at ~17 amps.
I think this reading to the starter solenoid is quite important from an understanding perspective. I have mentioned that I do not subscribe to the philosophy of connecting additional loads to the battery positive terminal. If the amperage going from the power junction to the starter solenoid at ~10.5 amps was connected to the positive terminal of the battery, the battery would be continually in an overcharging state even though there are other loads needing some of this power. It would be nice to think that the power would be discriminating and go to where it is needed and not affect any other component, but since there is no control over this the battery would be seeing more power than is intended.
I also connected my heated clothing into the electrical system. The heated liner increased the electrical system load by 5 to 6 amps – considerable actually.
Turned on the signal lights, and the electrical system current fluctuated approximately 1 amp - bounced around actually. Not to concerned because the signals are short duration use.
I have a 3 wire external alternator installed (55 amps) and it is more effective in reacting to the varying load demand than the OEM 3 piece alternator unit. You can see the current fluctuate ever so slightly 0.2 - 0.3 amps at idle and even when the engine RPM was increased to 2000 RPM.
I annotated a schematic with some arrows for current flow and letters for current at various locations. This schematic is when the engine is started and at idle.
Here is the schematic:
Point A is the one connection where the total electrical system load is represented. In the case of my bike at idle it is approximately 17 amps - good number to use.
Point D is approximately 10 amps of which this is split such that point C uses approximately 7 amps and point B (battery) uses approximately 3 amps. Point C is a 30 amp circuit that is connected to the starter solenoid battery terminal and is apparently only on the '85 and '86 FI models. This further indicates a best practice of not connecting directly to the battery positive terminal as there would be 10 amps at the battery instead of 3 amps - the short battery cable connection to the starter solenoid does do a specific design service. For those who do not want to do a lot of wiring change, a best practice of connecting extra circuit(s) at the the battery terminal of the starter solenoid should be preferred instead of at the battery positive terminal.
DC flow is reversed at point D when the electrical system voltage drops below battery voltage, but this expected to be for short period of time, not the norm. The DC flow will primarily be to the starter solenoid, not from it.
The remainder of the 17 amps at point A goes through the ignition switch at point E and is approximately 7 amps.
Thought I'd share some of my findings.
Cheers