Charging help please??
#1
11-12-2008, 06:43 PM
Charging help please??
90 FLHTCU with low miles - only 33k.
Recently it started doing some strange things electrically. Here's what usually happens....
Start it up and the volt meter only reads around 10. Runs for the first 5 miles or so like this and then pops up to 13. Hangs there for a while and occassionally drops back to 10 but then back to 13. When it is at 10 no turn signals work but I think the brake still works - hard to tell when riding.
Lately it drops to 10 when idling but when cruising it gets back to 12 or 13.
I'm guessing it is either the voltage reg - I suppose I can check volts going into and out of the reg - if plenty going in and only 10 coming out then it is on the verge of being fried.
Or, maybe the stator? Don't really know how this works, but I assume if it gets worn it doesn't create enough output and that may be why my voltage drops at low rpms?
Any help is appreciated.
Recently it started doing some strange things electrically. Here's what usually happens....
Start it up and the volt meter only reads around 10. Runs for the first 5 miles or so like this and then pops up to 13. Hangs there for a while and occassionally drops back to 10 but then back to 13. When it is at 10 no turn signals work but I think the brake still works - hard to tell when riding.
Lately it drops to 10 when idling but when cruising it gets back to 12 or 13.
I'm guessing it is either the voltage reg - I suppose I can check volts going into and out of the reg - if plenty going in and only 10 coming out then it is on the verge of being fried.
Or, maybe the stator? Don't really know how this works, but I assume if it gets worn it doesn't create enough output and that may be why my voltage drops at low rpms?
Any help is appreciated.
#2
11-12-2008, 07:06 PM
Unplug the regulator and check the voltage coming out of the stator (it's Ac not DC) your manual will tell you what it should be. If that is ok then it is probably the regulator (my guess from the info given, if the wiring and grounds are OK). Hope this helps. If you need more info on checking out things PM me.
#3
11-12-2008, 08:40 PM
Seasoned HDF Member
Dr.Hess' How To Diagnose Your Charging System
Buy about a $10-20 digital multi meter. Fully charge the battery (overnight on a 1 Amp charger).
Scale on DC Volts, around 20V max voltage scale. Nominal readings are given in brackets. Check voltage across battery terminals (12.8). Turn bike on. Check voltage (less than previous, ~12.0+, depending on headlight, accessories). Start bike and let idle. Check voltage (could be 12.0 to 15). Rev to about 2500. Check voltage (should be more than observed with bike on but motor not running, and more than with bike off. Ideally between 13 and 15.) Turn high beam on. Should be about the same, give or take a little. If the voltage is over 15 or 15.5-ish with a headlight on, I'd consider replacing the regulator and/or checking all grounds (battery to frame, regulator to frame in particular). If the battery voltage with the headlight on, bike not running is less than around 11.5-ish, I’d replace the battery. If it’s 10, it’s past it’s prime.
If you pass the above tests, your system is most likely fine, including the regulator and stator. If you don't pass, then:
Bike off. Meter set on Ohms, medium-ish scale, like 20K or 200K Ohms max scale, depending on your meter. Pull stator plug. Ground the meter black lead to a good chassis ground, like a bolt or even the battery negative. With the red lead, touch a different part of the bike, like the engine case at an unpainted part or another bolt. Meter should read low ohms, like 0. If it doesn’t, you didn’t ground the black lead. With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace.
The following is for single phase systems. I don't have a multi-phase and haven't had to diagnose anyone elses, so I haven't dug into those systems.
Set meter to lowest ohm scale, like 200 Ohms, typically. (Note: Not 200K ohms). Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms. The spec is in your shop manual. If it is infinity, stator is blown open. If it is 0, stator is shorted to itself.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. You may need to rig up some type of temporary plug. It is important that nothing can short to ground or to each other accidentally, or you will blow the stator if it wasn't blown before. An old plug off of your last regulator is a good way to do it, but, get creative and be careful. I can do it holidng the leads on the pins once the bike is running, but I don't like to. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM.
If you passed that stator test and failed the first test, your regulator is shot. If you failed any part of the stator test, replace both regulator and stator.
Buy about a $10-20 digital multi meter. Fully charge the battery (overnight on a 1 Amp charger).
Scale on DC Volts, around 20V max voltage scale. Nominal readings are given in brackets. Check voltage across battery terminals (12.8). Turn bike on. Check voltage (less than previous, ~12.0+, depending on headlight, accessories). Start bike and let idle. Check voltage (could be 12.0 to 15). Rev to about 2500. Check voltage (should be more than observed with bike on but motor not running, and more than with bike off. Ideally between 13 and 15.) Turn high beam on. Should be about the same, give or take a little. If the voltage is over 15 or 15.5-ish with a headlight on, I'd consider replacing the regulator and/or checking all grounds (battery to frame, regulator to frame in particular). If the battery voltage with the headlight on, bike not running is less than around 11.5-ish, I’d replace the battery. If it’s 10, it’s past it’s prime.
If you pass the above tests, your system is most likely fine, including the regulator and stator. If you don't pass, then:
Bike off. Meter set on Ohms, medium-ish scale, like 20K or 200K Ohms max scale, depending on your meter. Pull stator plug. Ground the meter black lead to a good chassis ground, like a bolt or even the battery negative. With the red lead, touch a different part of the bike, like the engine case at an unpainted part or another bolt. Meter should read low ohms, like 0. If it doesn’t, you didn’t ground the black lead. With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace.
The following is for single phase systems. I don't have a multi-phase and haven't had to diagnose anyone elses, so I haven't dug into those systems.
Set meter to lowest ohm scale, like 200 Ohms, typically. (Note: Not 200K ohms). Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms. The spec is in your shop manual. If it is infinity, stator is blown open. If it is 0, stator is shorted to itself.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. You may need to rig up some type of temporary plug. It is important that nothing can short to ground or to each other accidentally, or you will blow the stator if it wasn't blown before. An old plug off of your last regulator is a good way to do it, but, get creative and be careful. I can do it holidng the leads on the pins once the bike is running, but I don't like to. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM.
If you passed that stator test and failed the first test, your regulator is shot. If you failed any part of the stator test, replace both regulator and stator.
#4
11-12-2008, 09:13 PM
Dr.Hess' How To Diagnose Your Charging System
Buy about a $10-20 digital multi meter. Fully charge the battery (overnight on a 1 Amp charger).
Scale on DC Volts, around 20V max voltage scale. Nominal readings are given in brackets. Check voltage across battery terminals (12.8). Turn bike on. Check voltage (less than previous, ~12.0+, depending on headlight, accessories). Start bike and let idle. Check voltage (could be 12.0 to 15). Rev to about 2500. Check voltage (should be more than observed with bike on but motor not running, and more than with bike off. Ideally between 13 and 15.) Turn high beam on. Should be about the same, give or take a little. If the voltage is over 15 or 15.5-ish with a headlight on, I'd consider replacing the regulator and/or checking all grounds (battery to frame, regulator to frame in particular). If the battery voltage with the headlight on, bike not running is less than around 11.5-ish, I’d replace the battery. If it’s 10, it’s past it’s prime.
If you pass the above tests, your system is most likely fine, including the regulator and stator. If you don't pass, then:
Bike off. Meter set on Ohms, medium-ish scale, like 20K or 200K Ohms max scale, depending on your meter. Pull stator plug. Ground the meter black lead to a good chassis ground, like a bolt or even the battery negative. With the red lead, touch a different part of the bike, like the engine case at an unpainted part or another bolt. Meter should read low ohms, like 0. If it doesn’t, you didn’t ground the black lead. With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace.
The following is for single phase systems. I don't have a multi-phase and haven't had to diagnose anyone elses, so I haven't dug into those systems.
Set meter to lowest ohm scale, like 200 Ohms, typically. (Note: Not 200K ohms). Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms. The spec is in your shop manual. If it is infinity, stator is blown open. If it is 0, stator is shorted to itself.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. You may need to rig up some type of temporary plug. It is important that nothing can short to ground or to each other accidentally, or you will blow the stator if it wasn't blown before. An old plug off of your last regulator is a good way to do it, but, get creative and be careful. I can do it holidng the leads on the pins once the bike is running, but I don't like to. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM.
If you passed that stator test and failed the first test, your regulator is shot. If you failed any part of the stator test, replace both regulator and stator.
Buy about a $10-20 digital multi meter. Fully charge the battery (overnight on a 1 Amp charger).
Scale on DC Volts, around 20V max voltage scale. Nominal readings are given in brackets. Check voltage across battery terminals (12.8). Turn bike on. Check voltage (less than previous, ~12.0+, depending on headlight, accessories). Start bike and let idle. Check voltage (could be 12.0 to 15). Rev to about 2500. Check voltage (should be more than observed with bike on but motor not running, and more than with bike off. Ideally between 13 and 15.) Turn high beam on. Should be about the same, give or take a little. If the voltage is over 15 or 15.5-ish with a headlight on, I'd consider replacing the regulator and/or checking all grounds (battery to frame, regulator to frame in particular). If the battery voltage with the headlight on, bike not running is less than around 11.5-ish, I’d replace the battery. If it’s 10, it’s past it’s prime.
If you pass the above tests, your system is most likely fine, including the regulator and stator. If you don't pass, then:
Bike off. Meter set on Ohms, medium-ish scale, like 20K or 200K Ohms max scale, depending on your meter. Pull stator plug. Ground the meter black lead to a good chassis ground, like a bolt or even the battery negative. With the red lead, touch a different part of the bike, like the engine case at an unpainted part or another bolt. Meter should read low ohms, like 0. If it doesn’t, you didn’t ground the black lead. With the red lead, touch each contact on the motor side (stator) of the plug (the part stuck in the case). Depending on if your case has a male or female plug, if you can't see the metal part/pin of the plug, you can put a paper clip in the hole and touch the paperclip with your meter red. Meter reading should be infinity on all pins. If it isn't, your stator is shorted to the case, replace.
The following is for single phase systems. I don't have a multi-phase and haven't had to diagnose anyone elses, so I haven't dug into those systems.
Set meter to lowest ohm scale, like 200 Ohms, typically. (Note: Not 200K ohms). Check resistance between the two stator plug pins. Should be fairly low. My Book says 0.2-0.4 ohms. The spec is in your shop manual. If it is infinity, stator is blown open. If it is 0, stator is shorted to itself.
Set meter to AC Volts, 100V scale. Attach each meter lead to a stator pin. You may need to rig up some type of temporary plug. It is important that nothing can short to ground or to each other accidentally, or you will blow the stator if it wasn't blown before. An old plug off of your last regulator is a good way to do it, but, get creative and be careful. I can do it holidng the leads on the pins once the bike is running, but I don't like to. Start bike. Voltage should vary with engine speed. Specs are in your shop manual, but 35V at a couple thousand RPM is probably about right. My book says 19-26 V / 1K RPM.
If you passed that stator test and failed the first test, your regulator is shot. If you failed any part of the stator test, replace both regulator and stator.
Great write-up. Thank you very much for taking the time to do that. I see lots of posts on the General forum about whether people stop to help each other on the side of the road, but this is the same thing. You certainly didn't have to take that much time, or even comment at all, but it is greatly appreicated - especially since I absolutely HATE dealing with electrical issues.
I'll dig into it tomorrow night as it is calling for a heap of rain.
#5
11-12-2008, 10:28 PM
Road Warrior
If the charging system is original its possible the plug connector going into the inner primary isnt making good contact. I had a 1990 Ultra that did this on a road trip many moons ago. Found out that I had to replace both the stator and voltage regulator because of this design.
I later upgraded the charging system from 32 amp to 40 amps. By then Harley had redesigned the wiring to make it plug into the bottom the voltage regulator
I later upgraded the charging system from 32 amp to 40 amps. By then Harley had redesigned the wiring to make it plug into the bottom the voltage regulator
#6
11-14-2008, 07:46 AM
If the charging system is original its possible the plug connector going into the inner primary isnt making good contact. I had a 1990 Ultra that did this on a road trip many moons ago. Found out that I had to replace both the stator and voltage regulator because of this design.
I later upgraded the charging system from 32 amp to 40 amps. By then Harley had redesigned the wiring to make it plug into the bottom the voltage regulator
I later upgraded the charging system from 32 amp to 40 amps. By then Harley had redesigned the wiring to make it plug into the bottom the voltage regulator
#7
11-14-2008, 03:04 PM
HDF Community Team
Silicone Dielectric Compound - never leave (or stay) home without it! Nasty expensive in quantity, but most "fast food" parts stores (autozone, advance auto, Shucks) keep small squeeze packs by the checkout. Little goes a long way and put it on everything electrical. Connectors, bulb contacts, wire ends, everywhere an electrical connection is made up. My 87 has 95,000+ miles, all original bulbs! 
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