Charging problem

[HiGuy]

Battery is being maintained at 12 volts but the charging system will not increase and the battery slowly drops because of power spikes. Going to change voltage regulator/rectifier to see if that is problem this week. Could it be the alternator not working up to par? Please help, bought two months ago and it has been in the shop the whole time.

[bikerphil]

not charging

There are connections that you should try cleaning first, as they tend to corrode. The 1st. to do are the wires coming from the alternator. They are located behind the fuse block mounting panel (3 phillips screws). Also clean the voltage regulator connectors too. If your tachometer isn't working, neither is the charging system. The tach gets it's signal from the alternator. You can read more by doing a search at the top of this page (ex. "not charging"). Welcome to the forum!

[thewiz]

.... bought two months ago and it has been in the shop ....

Sorry for your trouble ... I feel your pain though. Maybe this will help ease it some ... I bought a disassembled SF one and three quarter years ago which was s'posed to all there and ready to re-assemble and ride, Yeah, right !! Every single thing on it has turned out to be total junk ... and now I have about 50 miles on it. No sooner did I get it goin' in January of this year than I wrecked it on essentially it's maiden voyage. Okay ... here we go again ... alrighty, then ..... soooo ... now I make it a bagger .... still a few hours from bein' on the road again .... I won't know how to act if I EVER get to ride it ... I have bought three others in the interim, fixed 'em and even sold one .... go figure. Patience is the key here ... these bikes are all old and continue to need some tinkering ...

As for your charging system ... most fail because of a bad battery. Have you load tested yours on a meter?

[mro]

Have a manual?

Easy to test if generator working or not.
Start engine and check voltage at battery.
Increase rpm over 2500. Depending on how good your meter is will read 13/14+ volts.

As noted above cleaning wire connectors is a good idea. The connector behind the fuse block can get enough corrosion to cause it to heat to the point of melting...


mro
BTW, even the after market manuals happen to have pretty good descriptions for trouble shooting many common problems.

[trbig]

It would also help to know what model and year you have since there were some changes. Mainly if it's an XS or an XJ 1100.


But MRO's quick check will work for any of them. You could simply have a dead cell in your battery.


Tod

[HiGuy]

thanks for the tips

I have it in at a shop and the guy doesn't seem to know what he is doing and won't take any advice. He put in a new battery so I'm hoping that isn't the problem and at the battery no matter what the RPM it is still just at 12 volts. The tach works just fine but the speedometer goes up really slowly and drops slowly too but after reading other posts that seems to be unrelated. I also order a voltage regulator that I'm hoping will arrive today (also got new tires and I'm excited about that) and that will fix the problem. The bike was jumped from a car battery so the mech thinks that might have fried the regulator. Will keep everybody posted.


1979 XS 1100 SF

[bikerphil]

another check

There's a quick test you can do to see if the alt is putting out. Find the green wire coming from the alt. (thin one), tap into it and attach to ground. This bypasses the regulator part of the reg./rectifier, and then check your voltage at the battery. It's ok to run it like this temporarily. It should be 14+ volts at 2500 rpm if the alt. is working. HTH

[trbig]

It is OK to jump the bike with a car battery..... BUT.... you don't want to have the car running when you do it.

Before replacing the regulator, it is grounded with the screws it's attached to the frame with. Cleaning these 2 points up may help. Also, there is the main grounding strap attched to the top rear middle drive allen bolt as you are standing on the left of the bike looking at it. Cleaning up any of these wouldn't hurt anything and may be the problem.

Tod

[randy]

Don't forget the battery ground strap where it connects to the frame. Cleaning all the other ground points and NOT cleaning the battery ground would be a lost cause.

[trbig]

Thanks Randy... I thought that I was meaning the whole strap there, but re-reading... It only looks like there at the middle drive I was talking about.


Tod

[fredintoon]

Get it out of there!

Hi Jaron,
out of the shop, that is. If you can afford to pay the shop rate for trouble-shooting you can afford the payments on a new bike. Plus if the bike will start the battery is good enough so throwing a new battery at your problem is the first resort of the incompetent.
The posts so far all have good pointers re cleaning connectors etc. Also look for what Mr. Stupid did, trap a wire under a clamp so the insulation extrudes off and the wire finally grounds out. I bought a complete set of used charging system parts before I found that pesky wire but if anything does actually let go I now have spares!
Here's a simple charging test. Point the headlight at a wall and rev up from idle. If the light gets brighter, it's charging. If it don't it ain't.

[HiGuy]

so I payed a lot more out of pocket then I ever planned for but I tried to get a deal and got burned instead. The problems are almost back to square one but I at least have a good deal more knowledge about my bike. I got tires mounted which cost me $116.05, $89.95 for a battery and supplies as well as in the end $100 for diagnosis of my problems. After I paid the guy and was on my way I noticed that my tach was not working (just kinda wiggling) even though when I took it in there it was working. and when I got home I hooked up my volt meter and the volts were at 11.67 and very slowly dropping. I was really frustrated but after looking over most fo the stuff on here and the manual I TESTED!!! (something this mechanic was supposed to do). I am so new to this that I wasn't even sure where the magnito was. So after I got adventerous and took things apart I realized that the previous owner had mention that he had a problem with the coil and I just dismissed it becuase I didn't know what the heck that was. He had broke the coil and used duck tape to create a connection and it had come loose again so I pulled it all the way apart and sodered a connection (it is only at 2.6 ohms instead of the 3.5 that it should be and the other thing, the stador I think, was at .5 ohms) again and I am now getting some current. It is still too low. It idles at about 11.5 volts and at 2500 rpm it is 12 volts and at high revs it tops about 12.5 volts.

Let me know if my assumption that I just need a new coil is correct, thanks.

[mro]

When you get a new OLD machine you need to start at the beginning to get em to run properly. The XS is a great machine and relatively easy to work on. Once you've gone thru it they are very reliable rides and only require regular planned maintenance.

You will not be spinning your wheels if you have not cleaned and checked all the wiring connections and grounds on your bike. You can test all you want but it takes just a little corrosion here and there to make it look like a component has failed. Generally takes a few hours to do, then when you test something you have a much better chance of determining where a problem might be.

No magneto, AC generator under right crank cover.
Coil?... if you mean the thing with the spark plug wires coming out of it...has nothing to do with charging (can get replacements from mikesxs.com, think info in tech tips)

Good luck....


mro

[fredintoon]

Terminology

Hi Jarod,
first thing is, your bike don't have a magneto. The plugs are fired by coils that get their impulses from a transistorized module that's a flat bleck plastic case about the size of a flat 25 cigarette packet somewhere on the rear fender which is in turn signalled from senders inside the left engine cover casting. The electricity comes from the battery. The battery is charged by DC current from the combined regulator/rectifier that's a cast aluminum finned box which bolts to the frame under the tank and which gets AC current from the bike's alternator. That's the massive pair of windings that live behind the right side engine cover casting. The outer ring of windings is the stator that makes the AC current. The inner ring of windings is the rotor that is fed DC current to make it into an electromagnet.
Note 1) The XS1100 alternator is a wierdie because the rotor don't rotate like on other bikes, it's bolted to the engine and what goes round is that big steel pole-piece that spins between the inner and outer stators.
Note 2) The tach is fed current tapped off one of the stator wires so no tach = no alternator (or that something ain't plugged in right).
I know this is no help to finding your problem but it may help us to help you.

[HiGuy]

Well the bike is now charging. Still have an uphill battle to get it to top shape since I am only getting about 10 miles to the gallon right now but I will probably get it in perfect shape by the time the season is over.

The problem was the alternator The stator seemed to be fine measureing in at around .5 ohms but the field coil only had a resistance of 2.4 but the one that I got off of a burned out bike for free was at 3.8. So now the idle voltage is 12 volts and goes as high as 14.32 volts. I still can't believe that I took it into a mechanic who had it for 3 1/2 weeks and could not figure it out. It took me from Friday the 13th (great day) until today to determine, isolate and repair. This was a very easy fix but that doesn't say much for this guy.

My wife has officially given the bike a name...

"Charley Classical Clunker"

Look forward to some more about my future exploits.