Topic: !#@$ing charging system

[JZEROE]

Pretty sure my charging system on my '75 550 took a crap on me yesterday. All the standard indicators (new battery, btw): Won't start w/out a jump, even with kickstart. Dies soon after the jump.

So yesterday I spent two hours hopscotching across town from jump to jump, finally winding up at a body shop who let me hook up to the 15-amp charger for an hour. That got me to my shop about two city miles away, and when I pulled in, my battery was at 12.3v.

Anyway, I pretty much know how to find out--attach voltmeter to leads, check voltage at 4k rpm--but I do have a couple more specific questions:

-What should the resistance be on my rotor? And can you refresh my mind about the best way to test? Here's what I DO remember: isolate brush from shaft with matchbook or something, use voltmeter to check resistance between rotor shaft and windings??? It's been so long...

-Do stators generally go bad on these bikes? Would I also just find a power-in and power-out and test for resistance?

-What should the input signal to the regulator look like? I don't have a scanner, but I can make note of peaks and valleys on the voltmeter.

-I have the round-style regulator. Are they overhaulable? Is there a cheapo alternative, like from a Ford or something?

-Is there a possible upgrade? I do a lot of city driving, so investing in something more robust would be a good idea for me.

Thanks!

J

[mustangcar]

heard the stator are pretty reliable,gee could be too many things,heard what usually goes out is the rectifier or the regulator,,replace those two first id say, read the forums i read some good posts on tests you can perform,also cleaning out the  contacts inside starter switch,i saw a guy fix his charging just by doing that

[TwoTired]

So yesterday I spent two hours hopscotching across town from jump to jump, finally winding up at a body shop who let me hook up to the 15-amp charger for an hour.

If your keep putting a high current charger on that little battery, it will overheat, and eventually ruin the battery.
The 550 battery is rated for 12 amp hour.  Normal safe charge rate is 1.2 amps.

That got me to my shop about two city miles away, and when I pulled in, my battery was at 12.3v.

After a one hour rest after charge, a fully charged battery s/b 12.6V

-What should the resistance be on my rotor? 

The 550 rotor is a formed lump of steel.

And can you refresh my mind about the best way to test? Here's what I DO remember: isolate brush from shaft with matchbook or something, use voltmeter to check resistance between rotor shaft and windings??? It's been so long...

You have no brushes.  You have an exited field alternator.  Driven by the Vreg.  The field coil should measure 4.9 ohms.  Can be measured from the regulator terminals White and Green while disconnected.  Be sure to account for meter lead and wiring resistance in that very small measurement.

-Do stators generally go bad on these bikes? Would I also just find a power-in and power-out and test for resistance?

I've not seen one go bad.  I would expect it to be unlikely.  You can do a resistance check on this, too, if you have good test equipment and good test technique. .35 ohm between each of the three yellow wires.

-What should the input signal to the regulator look like? I don't have a scanner, but I can make note of peaks and valleys on the voltmeter.

The INPUT signal is 12V from the battery when the Key switch is activated.  The OUTPUT signal from the regulator to field s/b battery voltage when the battery is low, 9V when the battery is charged, and 0V when the battery is overcharged. (about 14.6)

-I have the round-style regulator. Are they overhaulable? Is there a cheapo alternative, like from a Ford or something?

Round?  Non-stock. So, no clue here.  Maybe with a picture, someone can identify it.  Pinhead will likely put in a sales pitch for one he likes soon, though.  Or, look for one of the sigs in his posts. I'm still using the stock ones on all my bikes.

-Is there a possible upgrade? I do a lot of city driving, so investing in something more robust would be a good idea for me.

The regulator doesn't make ANY power, that happen in the alternator.  The best it can operate is when the field coil is energized while given full battery voltage.  Even then, it is dependent on RPM.

The stock bike actually loses battery power at idle speed, as the electrical load on a stock bike is about 10 amps (lights on) and at idle with the alternator in peak condition, puts out about 4 amps or less.

If you have put in a brighter, higher wattage headlight, 3 ohm coils and a Dyna S, you've increased the power consumption of your bike.  The battery will drain faster at idle and you will need to rev to higher numbers to even begin to recharge the battery.

Your description makes it unclear whether you still have a separate Rectifier.  A failure there will also severely reduce to output capability of the charging system.

Cheers,

[Jerry Rxman Griffin aka MuthaF'er]

TT will probably be along any minute. He is THE SUPERMAN of our electrical world and eats Kryptonite for breakfast. That's just how badass he is   Seriously, so pay attention to what he says!

I'd start off by telling you that you probably need a new battery. 15amp charger is too big and your battery was probably toast anyway. How long have you had it, was it properly trickle charged before the first use!, and have you left it plugged into a float style trickle charger over winter(s)?

Secondly I'd tell you to go through the 30+ year old wiring harness, disconnect EVERY and I mean EVERY friggen connector, bullet and spade on both sides, apply dielectric grease, tighten them and reconnect. Yeah, EVERY ONE. Yeah, it's a pain in the ass but just do it and be done with it. Needs to be done. Period! Slight corrosion or weak connections on one drops voltage but multiply that by say 50-100 and what do you reckon happens.

OK, as we say (new saying) in SOHC4 world.........    It's TT Time. I yield the floor to our guru.

I told you so..... just as I was blowing hot air he was lurkin. Lloyd, you da man.

 

[mystic_1]

I told you so..... just as I was blowing hot air he was lurkin. Lloyd, you da man.
 

Guess he was finishing up his bowl of Kryptonite Krispies before posting lol!



I look forward to TT's posts when I read the forum.  Always chock full of great data.


mystic_1

[JZEROE]

I'd start off by telling you that you probably need a new battery. 15amp charger is too big and your battery was probably toast anyway. How long have you had it, was it properly trickle charged before the first use!, and have you left it plugged into a float style trickle charger over winter(s)?

Only had it on the 15-amper for an hour. Normally I use battery tender. And yeah, I hooked up the new cell (1 month ago) up to the tender for 24hrs before I used it. You think an hour on the 15-amp charger toasted me? It was still at 12.3v after a 2 mile ride

Secondly I'd tell you to go through the 30+ year old wiring harness, disconnect EVERY and I mean EVERY friggen connector, bullet and spade on both sides, apply dielectric grease, tighten them and reconnect. Yeah, EVERY ONE. Yeah, it's a pain in the ass but just do it and be done with it. Needs to be done. Period! Slight corrosion or weak connections on one drops voltage but multiply that by say 50-100 and what do you reckon happens.

Haha! Awesome! I am going to send this to a buddy of mine who told me I was crazy for doing this the other week. I think I've mentioned before that I tend to go down the rabbit hole when it comes to maintenance.

[bryanj]

Somewhere on this site, i know cos i sent it, is a Honda bulletin sl 90 entitled "Three-Phase charging system" Read that and understyand how the alternator and regulator work.
In 30 years i NEVER seen an elactrically duff field coil, stator, regulator nor rectifier EXCEPT a couple of rectifiers blown by bad owners and alternators damaged by road rash but i'm sorry i dont count those.
Regulator points can "stick" mechanically but are incredibly reliable otherwise

[JZEROE]

And thanks TT, for the advice

I'll be heading over to the shop tonight to evaluate, and will keep you all posted.

[hapsh]

Going over every connector is way overkill unless you are having multiple electrical issues.  If you have aged connectors between your lights and accessories it does not make them draw more current or use more power from the charging system, it actually drops the power draw.  So I wouldn't worry about those areas too much.  I would however agree that you need to check, clean, and tighten your connectors between your alternator, battery, starter, regulator, rectifier, and coils.  Also it is pretty easy to check your alternator output and the operation of your regulator.  Just hook up a multimeter to your battery while it is running.  You should be somewhere around 12.5 volts at idle (depending on battery charge), then as you rev up the voltage will get higher and higher topping off about 14.6v .  TT is correct, there is a power loss at idle, you wont stop draining the battery until about 2k rpm.  If your regulator is working correctly you will actually see the voltage drop slightly when you get your rpms up high enough and your battery is fully charged.  There is a regulator setup procedure I found at oldmanhonda's site.  It is very useful because you can raise or lower the charging voltage via an adjustment screw inside the can.  I also found a neat little troubleshooting tool at Harbor Freight.  Its a little charging system tester that is about the size of bic lighter.  It has a series of LEDs on the top indicating the charging voltage.  It also has a magnet on the back so it stick to your gas tank temporarily so you can ride the bike around and watch your charging voltage at different speeds and rpms.

[TwoTired]

Going over every connector is way overkill unless you are having multiple electrical issues.  If you have aged connectors between your lights and accessories it does not make them draw more current or use more power from the charging system, it actually drops the power draw.  So I wouldn't worry about those areas too much.

I would argue that it CAN make a difference, and moreso in circuits that carry significant current.  Why?  Because the corrosion is resistive.  Passing current though a resistance not only drops the voltage, but generates heat, which is power wasted rather than delivered.  It wouldn't matter so much if the alternator provided far more power than is ever used.  But, if 10% of your power generation is wasted as heat, dissipated in connectors, then that makes the battery lose more at idle and charge less quickly at higher RPMs.
Do address connector oxidation in the higher current carrying circuits first.  But, there is benefit to having ALL the connections as low resistance as possible.  And, once you've cleaned them, be sure to coat them with something that deprives the metal of oxidation, like dielectric grease.  It can't oxidize if oxygen can't get to it.

Cheers,