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My 1975 FXE does not charge. Same voltage at the battery with bike running or not. Is there some way to test to see which component is at fault? Don't want to start buying stuff just to eliminate the possiblilty of that part being the culprit. Thanks:huh:
 

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tractorhunter said:
My 1975 FXE does not charge. Same voltage at the battery with bike running or not. Is there some way to test to see which component is at fault? Don't want to start buying stuff just to eliminate the possiblilty of that part being the culprit. Thanks:huh:

I will assume that you don't have the factory manual.

Remove the two pin plug from the left engine case. That's the one that feeds the regulator. Insert a meter (VOM, set on 100VAC range) into the two pin plug on the case and start the engine.

You should see about 40 VAC at 2,000 rpm. If nothing, then your issue is likely with the stator, unless the magnets are totally shot on the rotor. More on this in a minute.

If you have the necessary AC voltage at the engine case connector, about 20 VAC per 1,000 rpm, then reinsert the plug and remove the cable from the battery where it comes from the regulator. It's the long black cable that goes along the frame under the motor on the right side. Check that cable carefully for breaks, cuts and terminal condition where it connects to the battery. If good, then, just to be sure, check for 14 Volts DC between that wire and ground with the engine at about 2,000 rpm. If no juice, then you have a bad regulator.

So to recap:

If 20 VAC at engine connector at 2,000 rpm, then stator/rotor is OK.

If no Voltage at engine connector at 2,000 rpm or low voltage, then stator/rotor is Ka/Ka.

If voltage OK at stator/rotor but no DC output at regulator black wire, then regulator is Ka/Ka.

About the rotor. Assuming that your system is ten or more years old, I would opt for a complete replacement with new stator/rotor/regulator as a complete matched unit. They are available readily in 32 amp configuration.

I replaced my system a few years ago and it's great. I got a whole 32 amp setup in a box from HD for $189.95. I wouldn't do it piecemeal since it's best to get a matched set and all components will then be new and working together.

Hope this helps.

:)
 

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Discussion Starter · #3 ·
Thanks

Classic, Thanks, thats just what I needed. I do have the manual but my buddy has it. Still, your description was clearer than what I remember the manual saying anyway. I should get to it this week and will let you know how I make out. Thanks again, Dan :cheers:
 

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You're welcome. BTW, I looked at my manual and discovered the following about the FX/FL charging systems. If yours is stock, it's probaly a 16 amp (total) charging system. That's pretty small. So as I mentioned above, if you have to replace, a 32 amp job should be sufficient. I think there are stronger systems in the aftermarket but I would stick to HD parts if at all possible. (they are made in a higher-class area in China. :) )

The book shows:

Regulator voltage output should be 13.8 to 15 VDC @ 75 deg. F.

Various years:

19781/2 to 1980 = 16 amp regulator
1981 = 17.8 amp regulator
1982 and later = 22 amp regulator.

Harley had different stators for 71 through 75, 76 through 80 and 81 and later. Rotors were different for 71 to 81 and 82 and later. Rectifier & Regulator Assemblies were different for 71-75, 76 to 80 and 81 aand later. That's why it's best to purchase a matched set.

32 amp systems are available as I mentioned,.
AC voltage specification is 19 to 26 VAC per 1000 rpm. Stator coil resistance should be 2 to 4 ohms.

Good luck.
 

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Discussion Starter · #5 ·
Update

Can't start the bike right now, waiting for some exhaust gaskets but I did check the plug from the engine to the regulator. It's a 4 prong plug with the left 2 plugs being closer together. If I test any of the plugs to ground I get about .4 ohms resistance. I get about 1.2 between the top two prongs and .2 between the bottom 2 , 1.5 between right hand prongs and .5 between the left 2 prongs. With all this resistance, does it mean my stator is fried? thanks again, Dan
 

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tractorhunter said:
Can't start the bike right now, waiting for some exhaust gaskets but I did check the plug from the engine to the regulator. It's a 4 prong plug with the left 2 plugs being closer together. If I test any of the plugs to ground I get about .4 ohms resistance. I get about 1.2 between the top two prongs and .2 between the bottom 2 , 1.5 between right hand prongs and .5 between the left 2 prongs. With all this resistance, does it mean my stator is fried? thanks again, Dan
You got me there. Someone else may know about a 4 pin system. Both my original 22 amp factory setup and the Harley-Davidson replacement 32 amp kit are two pins only. The book that I have shows a test only for the standard two pin system. My Service Manual is FL/FX Models, 1200/1340, 4 speed 1978 1/2 to 1984 P/N 99482-84.

Perhaps you have a different year or an aftermarket kit?


Good luck.
 

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Discussion Starter · #7 ·
Stock

Stock 1975 unit. Maybe the exhaust gaskets will be in today and I can do some testing. :yes:
 

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tractorhunter said:
Stock 1975 unit. Maybe the exhaust gaskets will be in today and I can do some testing. :yes:

Well, the test would be the same. Just a matter if discovering the VAC pins that are feeding the regulator. There will probably only be two that show the necessary voltage of around 20 VAC per 1000 rpm.

Guess that the pre-1978 bikes had a 4 pin unit.

Let us know what you discover.
 

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I had the stock charging system on my '76 FLH and for the first year I had to recharge my NEW battery every couple weeks just to get it started.

After my warmed over restoration last spring I installed a new package that included new rotor, stator and regulator. This is supposed to be a 34 amp system. I had to also put in another new battery, same at the first new one I had. Since then I've driven the bike about 2,500 miles and let it set for months over the winter in my garage and it's started every time without any extra charging necessary.

I now have my turn signals changed over to dual elements so they can be on with the lights. I run with my headlights on and my fog lights on all the time and I'm very happy with the new charging system. I think it was somewhere in $275 range from a catalog wholesaler.

My thought would be to upgrade if it has to be torn down. It's well worth the effort and money. It's very easy to install as well.

Later dudes.

__________________
'76 FLH Electra Glide Project
'55 Chevy Nomad Gasser 540 ci / 660 hp

http://www.picturetrail.com/dan_lockwood
 

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I have a question for you along the same line here. I have a 75 FLH. Been having charging issues as well. I now understand that this is a 16amp system because of the 4 plugs like the other guy here. I can see the voltage go up at the battery terminal when you rev the bike so the charging system is charging but on a day long ride, I'll have to kick it to start it. So my theory is that it is just not charging enough.

Two things I have changed. Dual filament bulbs in the rear turn signal for turn and running lights. And I had a real toggle switch problem with the passing lamps so I hooked them up straight to run all the time with the Headlight. Am I drawing to much for this system with having the passing lamps on constantly?
 

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hi got a question on the same line, got a 1979. battery not charging reading 12 volts dc rum
nning or not. getting 30v ac out of pins on the case ups to 50v when rpm increases. mettering between the two pins shows a closed circute which means the windings are good. now the question. I read on another site you need to need to check each pin to ground and should get no reading. however I can check both pins to ground and both show continuity to the ground. from what the other site said if you do get a reading between the pins and ground the system is shorted out. but if my charging system is shorted out why would it still be puting out the correct ac voltage when running??
 

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You are right about the grounded pins but if you aren't showing high ohms it just may be oil conducting but I would go inside and check it out anyway.From your readings,your regulator is done...Just because it may be shorted doesn't mean that it can't have output...just for shits and giggles try taking a reading with your meter between bat ground and the engine for volts AC...may not work but if you are sending volts to ground they should show up somewhere...
 

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The older bikes had the 4 wire mechanical regulators, made by botch or Delco. the system was pretty much junk, and always a problem. Plus when components are changed it usually needs to be polarized.
I would highly recommend using a factory type 1982 or later, 2 wire, system. The entire system must be changed, but is a direct bolt on. Either the 22 or 32 amp systems will work. Stator, rotor and regulator, you should wire a breaker In between the battery and the lone from the regulator, just a safety basically, same amperage as the system, or as close as possible.
You won't be sorry
 

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Thanks for the input guys gave me some more to look at. Kinda hate to put the bike down right now riding weather in Indiana ain't over till the snow covers the ground! Lol my thoughts were since it's the factory alternator maybe dust from the brushes could be making it show ground. Will look for ac volage from the =nine but think for now may just replace the regulator & see if that buys me some time. When it gets below zero I'll tear it down & replace the rest.
Thanks again
Cc
 

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Most of the info in this thread is incorrect and basically useless, I would not recommend connecting the AC alternator to the DC battery. Upgrade to 1 of the 22 or 32 amp systems guy with the passing lamps on constantly for one
 

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Most of the info in this thread is incorrect and basically useless, I would not recommend connecting the AC alternator to the DC battery. Upgrade to 1 of the 22 or 32 amp systems guy with the passing lamps on constantly for one
+1 on that. I upgraded to a 32 amp system 4 years ago. The kits out there fit '70 thru '99. Many to choose from.
 

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Ive been putting the swap to 32 amp system off too long. Need to get it done before spring as I want to travel. Is there any particular system I should be buying? I see a couple different ones available.
 
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