Help diagnose xj so owner won't give up hope on a great bike

So..
My friend bought a MINT 82 XJ650 this past spring. Test rode great lots of power. Problem is, this thing is eating batteries. Brand new battery after purchase, bike makes it 50 miles, make stop; get back on bike, battery dead. Trailer to shop. Shop says voltage reg. needs replaced. Replaced. Ride 75 miles. Bring home. Go out next day, battery dead. Charge battery. Ride 50+ miles, next day, battery dead. Swap OK battery out of my XJ ride 75 miles, come home, next day battery dead. Etc... I know the current battery is trashed by now but where do I start. I am thinking alternator brushes. But this bike only has 13k miles on it. Opinions please?

 

what is the voltage reading from the battery:
- BEFORE starting
- when running
- after stopping
- the next morning.

I'm guessing you have a leak. You've replaced both the rec and the battery. I guess the next possible fail point aside from the leak would be the actual charging system, and the wiring back from it. You'll know that as soon as you hook a voltometer up to it when it is running.

 

Brushes are the next thing to check. Should have been the first. If the battery goes dead after a ride then it isn't getting charged. And the shop said regulator? What they should have told you was whether or not the voltage was reading above 14 VDC when the bike was running and that they tested the battery and it proved good under load. The regulator can be checked also. If you kept the old one I would check it and make sure it is bad. I seriously doubt that it is.
So check like Woot said, and tell us the readings. Another good thing to know is if the battery goes dead while sitting in the bike overnight. That would tell you there is a short drawing current. If it only goes dead while riding then I highly suspect the charging system.

 

Re: Help diagnose xj so owner won't give up hope on a great

I don't have a voltmeter. Guess I need to get one and learn to use it. The shop said that it was reading low under load and with the new reg. it was reading 14.5 if I remember. It is a shop I can trust, I am just not sure the mechanic is too adept with electrical problems. How hard is it to check the brushes by looking at them and is it normal for them to be worn at 13k?
The battery seems to go dead WHILE riding. Last time I noticed the lights were dim and I told her not to shut it off till we got it to her house, and sure enough it wouldn't restart.
She is getting embarrassed by the bike because of things like having to push start it in front of a crowd of people at a poker run and had to trailer it anyhow, and has let her sit in the middle of downtown traffic because she stalled by accident and it wouldn't restart. We can't plan on taking long trips for fear it will die. You can't always depend on a friend having a trailer and towing is expensive...
Thanks for any help
NTgirl
Will try to attach pic of the bike. I posted pics of it here once before....

 

Re: Help diagnose xj so owner won't give up hope on a great

pic

 

Beautiful bike, in great shape too. I wouldsay it's the brushes giving you the problem

 

Re: Help diagnose xj so owner won't give up hope on a great

Nice clean bike! don't give up on it, looks to good. electrical problems can be a bear sometimes. at least from what I have read, it is going dead while riding & not while sitting, finding a current draw can get a little hairy. good luck & let us know what you find.

 

Remember, when they check the load, they need to ensure the RPM's are over 5000 - that's when the battery hits recharge mode.

It does sound like the alternator on the bike may have worn bushings and the bike is soley running on the battery.

Voltage regulator? Sounds like a shop that were grasping at straws and not checking the #1 issue - your alternator.

Bring both the battery back and the new voltage regulator and find another bike shop. OR, you can ask us here. Go to radio shack and buy a cheap $30 voltmeter. Check the voltage at the battery at 5000+rpms then at the alternator.

 

1st thing you should check is to remove the ground cable from the battery and connect a trouble light between the terminal and the cable.
If the light in the handle lights up you know you have a draw (short).
If it doesn't then I'd check all the other things in this thread.
If it does, look for any accesories that may be on (lights, radio....etc)

A circuit tester is cheap and every tool box should have one.

I cant live without one

 

Re: Help diagnose xj so owner won't give up hope on a great

You can even pick up a voltmeter at Walmart. They are in the section that has the spark plugs and auto replacement bulbs. They were $10-12.

 

Look at the Alternator Brushes. You have the CLASSIC Symptom of way below limit brushes.

Below limit Brushes will eventually damage the Stator's slip-rings.

Pull-apart the Plastic Connection from the Voltage Regulator and closely examine the Regulator's electrical contacts for melting and over-heating.

If the connection shows melting around the RED Wire ... you should line-up a Used Regulator.

Under limit brushes do not supply enough current to the Regulator, which may get surged and usually damaged if the bike is frequently jump-started from an automotive electrical system capable of generating more amps, at idle, than the bike's electrical system can safely handle.

 

Re: Help diagnose xj so owner won't give up hope on a great

OK... I think I have a circuit tester, so I will try that suggestion as well as checking the alternator brushes. Both sound easy enough. Also will check the regulator to make sure we have not fried it. (we have not jump started the bike) Remember this is a new regulator... Will do those things this weekend and then let you know what I find. OH, if the brushes are worn is this something I can pick up at a place that rebuilds alternators or do I have to order them? The only ones I found online were $20 each. I don't even know if I need to replace them yet, but just wondering.

 

P.S. once you get the voltmeter/ohmeter, you can check the resistance of the stator and the rotor to try and track down problems that way. There is a REALLY great write up on XJ electrical troubleshooting, diagnosis, and testing at:

http://www.geocities.com/MotorCity/Speedway/7795/


Everyone should bookmark that page and better yet, print it out. Lots of exceptional info there......

BTW, you might want to remove the starter motor before you remove the alternator cover....the alternator wires (by design, no less) run UNDER the starter motor after they exit the cover.....which not only makes it a real bear to turn the alt. cover over (insides facing you) when it's removed, but makes it almost impossible to replace it. I re-routed the alternator wires around the "side" of the starter motor (inbetween the alternator and the starter) and then around back of the starter motor, where there is a lot of clearnace, and the wires are long enough to do this. About a 6 on the PITA scale, but it beats the 12.5 on the PITA scale of trying to put the alternator cover back on with the alternator wires pinched under the starter.

And why in the world would the factory pinch those wires under the starter motor? And yes, I looked at the factory diagram, that's how they are supposed to be routed!!! (under the starter motor).

 

Re: Help diagnose xj so owner won't give up hope on a great

One really cheap O way if seeing if you alt is doing anything at all is when its dark out rev the bike with the headlamp facing a wall or something if when you rev thee engine the light gets brighter it's at least doing something. I use this simple test everytime i go out riding any distance.
I hold my hand in front of the head lamp to see if it's first on and then if the alt. is putting out. This is doesn't mean don't replace the brushes if they're worn. Just that you should make it home.

 

Re: Help diagnose xj so owner won't give up hope on a great

I hate to be a pain but could you show some documentation for this?

I ride the bike around town at usually under 3k RPM's and your statement doesn't make any sense to me because it would seem to make the XJ's useless for inter-city traffic for any serious length of time. :?

 

Re: Help diagnose xj so owner won't give up hope on a great

Sorry - I meant 4k.

*zombie voice*
Neeeeed Coffffeeeeeee........ ;-)

 

I looked through some manuals on the XJCD and they state the engine RPM at 2,000 or more, the battery voltage should be 14.2 to 14.8 V.

 

Nimitz and Nick, your both right - as soon as the bike is running it should have some charge (if your battery was 12 volts going in, when the bike is idling it should be up higer than 12v - if it is charging) thus they (and all other bikes, and cars for that matter) are driveable in city conditions. The bike does not need to be anywhere near 5000 rpm to charge.

 

Technically speaking:

9 to 11V when the engine is started and at idle rpm's.
Gradually increasing as rpm's increase.
12V produced at 1,400 rpm +/- 250 rpm depending on load.

Increasing voltage as rpm's increase above 1,650 rpm - where 12V output should be surpassed and further increasing to 14.2V at 1,750 rpm -- with and additional increase to 14.5V at 2,000 rpm -- holding steady at 14.5V at 2,000 rpm's and above.

 

Re: Help diagnose xj so owner won't give up hope on a great

So I just now got the time and space to pull the alternator apart. How do I measure the brushes? There are lines on them, do I measure from the line, from where the brush comes out of the holder, or do I take the brushes out and measure them? Help please. Also there is a dark circle on the alternator where the brushes rub. Should I find some glass paper or copper cleaner and clean it off or is that normal?
Nighttraingirl

 

Re: Help diagnose xj so owner won't give up hope on a great

Measure from where they come out of the holder. In other words, how much is "showing".

Dunno for sure about cleaning the dark circles off....I would assume that any sort of cleaning that doesn't mar or scratch the surface at all would be alright.

 

Go by specs on those brushes:

New = 17mm
Service Limit = 10mm

I think that line you see is like a wear bar on a tire ... that represents "The Limit" ... See a line = Good to Go. No line = New Brush time.

You can use a cleaner to get do most of the dirty work getting down to a good look at the condition of the slip rings. Rinse with Isopro-alcohol.
If there's bluing, light scorching or arcing traces ... you have to Glass paper rub it out ~~> Following the exact curve of the rings all the way around.

 

Re: Help diagnose xj so owner won't give up hope on a great

The best cleaner I know of is brake parts cleaner, just make sure you have no voltage going through, or disconnect the battery as it is flamable. But brake parts cleaner cleans just about anything automotive or motorcycle dirt and wear related, cleans quick, and evaporates quickly, can reconnect your battery in just a few minutes. It'll sure clean the grim off under the bike too.
I also heard an eraser on a pencil is good for cleaning the winding surface and brushes in the alternator.

As for the charging system thing at 5000 rpm, I about laughed when I saw that too. The charging system picks up charging around 800 -1000 rpm, below 800 or near factory set idling, is done on the battery alone. I personally like my idle up around 1000 -1100 rpm so there's charging even when sitting still. This is why you have to keep the rpm's up if running the bike while the battery is disconnected, a bike will run on the charging system, but if you let it drop to idle, it'll stall out with no battery. This isn't good to do as it can destroy the diodes eventually but you can usualy get a bike home on a dead battery and that's why.

You can check the stator to see if a winding has opened up, unplug while engine is running, each of the wires should be outputting voltage, from the wire to ground, if one isn't your stator is bad. I had to replace my Vmax's not long ago for this as it's battery's weren't lasting very long either.

 

Re: Help diagnose xj so owner won't give up hope on a great

I took the brushes into the shop and they said they are OK. So I am going to see how the rings clean up with an eraser (suggested here and also by the shop) and go from there. If that does not work it is going to the shop so they can start troubleshooting. I think I best let it up so someone who has experience with electrical stuff, as I do not. I will only get frustrated if I don't understand what I am looking at. Thanks for all the help everyone, I will let you know what happens.
Next on the agenda, two leaking oil sensors and a leaky head gasket. Sigh....

 

Re: Help diagnose xj so owner won't give up hope on a great

If you take it to the shop because you don't have the experience, you'll never get the experience. :wink:

 

What we like to do, first, is help each other. That way, you might be able to avoid having to bring the bike into the shop.

If you use the site a little more to your advantage ... you might be able to find someone close to where you live that might be able to bail you out and save you some bucks. You never know.

Your location beneath the Avatar ... and your bike profile in the "Signature" section would be a good start.
____________________________
(Year Model Total Miles Stock or Modified.

 

I have gotten lots of useful info, just feel like I am at a dead end, I guess.
Lets see if this profile info shows up....

 

Well that didn't show up. Lets try again. Anyway, its Waynesboro, PA for the location.

 

I also have an '82 but I'm still messing with it to get it running. Near Albany NY though, so I'm not too close...
Didn't you post a pic of you and your bike, Nighttraingirl? I thought it used to be in your profile.

 

Re: Help diagnose xj so owner won't give up hope on a great

Well the bike is back together and running. While the owner was cleaning the rings in the alternator, I cleaned every electrical connector that I could find, and the battery terminals. All wiring seems in great shape. EXCEPT on closer inspection of the fuse box two of the circuits have inline fuses, which is fine. They left the main fuse in the old fuse block, and get this, the remaining fuse is non-existent! The wires are connected directly and have tape around them. I will be looking for a fuse block ASAP and will be installing one in my bike also. Makes me wonder if the fuse kept blowing so they just bypassed it. I hope not. Didn't have time to determine which fuse it is yet, of course they are not labeled. My bike is wired with inline fuses. Is it way better to use a real fuse block and the ATC fuses or is the inline OK?
She took the bike for inspection today and said it ran fine, restarted fine, etc. That was only about 20 miles though, because she was alone and afraid of being stranded. Also, I have bought a multimeter and between the two of use we are gonna figure this out, one way or another!

 

The only preference between having a Fuse Block and running with Inline Fuses boils down to how much work you want to do getting-rid of the old panel and installing the new panel or fuse holders.

It's MUCH easier to install Inline Fuse Holders than it is a new FUSE BLOCK.

There isn't much wire extending from the tape-wound loom ... to run to the NEW FUSE BLOCK. To be able to make good connections to the New Fuse Block ... you need to splice-in extensions from the Main Harness for some "working slack."

Or ... solder some extensions to one side of the New Block.

 

Re: Help diagnose xj so owner won't give up hope on a great

I got a multimeter as suggested, and I am able to test the battery and determine that it is NOT charging. It reads about 12 but only goes up to about 13 at 2000rpm. The book says to test the alternator and stator, set the multimeter on ohmsx1. My multimeter does not have a setting like that. It is a Craftsman multimeter model 82140. The ohms scale says 2000k, 200k, 20k, 2000, and 200. How do I set this thing to test the resistance on the alternator plugs? I tried the 200 setting and the readout says 1 before you even touch the probes to anything, and it does not change when I try to test. So I tried on my xj, and couldn't get it to work either. This may be a dumb question but is the ignition supposed to be on? I tried both ways, still nothing.
The alternator plug with the three white wires was completely melted together. I got it apart, but needless to say it is in sad shape. Should I just find a new connector and splice it in and retest at the battery, before replacing the alt. or stator? Also does it have to be an OEM connector or can I just find any three blade connector and use that?
Sorry for the long post.. :roll:

 

Re: Help diagnose xj so owner won't give up hope on a great

Your multi-meter is reading 1 because it's reading a open circuit. If you touch the probes together, it should go to 0.00 (infinite).
The key doesn't need to be on, but the components that you are trying to test should be unplugged from the harness.

Those three white wires need to have a good connection for the charging system to work. It doesn't matter if you go with a stock plug, a extension cord plug, or just solder them together, they just need a good connection. You don't have to worry about mixing them up and it not working, any white wire can be tied to any white wire. (they're running 3-phase AC, so they don't care if they're hooked up exactly as original or not)

 

Re: Help diagnose xj so owner won't give up hope on a great

OK, the I understand the open circuit theory, but how do I get the test to work, it does not work on my xj either and the charging system is fine on it? I thought I was lucky to have a working bike to refer to when trying to fix the other one but it didn't work out that way. When I touch the probes together on the meter, on the 20 setting it reads .7 . On the 200 setting it reads 0. When I try to test the alternator plug, it just says 1, and I did have the connector unplugged. Thanks. I am trying to learn something new!

Oh also, the connector is also not only melted but still getting very hot as well as the outside of the alternator being very hot. Could this all stem from the bad connection or do you think the alt/stator is shot? The voltage reg. was already replaced and I fear it is ruined again because of the bad alt. plug.

 

Re: Help diagnose xj so owner won't give up hope on a great

1) If the meter reads anythng other than 0.0 probe to probe on the 20 ohm setting adjust it to zero (if it's adjustable) or replace it.

2) White - White (Stator Coil) resistance should be 0.41-0.51 ohms at room temperature. This is tested at the 20 ohm range on the meter. (See why having .7 builtin is a problem?)

3) Green - Brown (Field Coil) resistance should be 03.6 - 4.4 ohms. Again use the 20 ohm range on the meter.

I'll try and meter mine tomorrow evening just for comparison.

 

Re: Help diagnose xj so owner won't give up hope on a great

UH oh. Don't tell me the meter is broken already. It's brand new, and the first time I used it. I have to correct what I said, the probes touched together read .7 on the 200 setting and 0 on the 2000 setting Sometimes it just sits at 1 and won't even go to 0. There is no setting lower. It goes 2000k, 200k, 20k, 2000, 200. Do I need a different meter, that goes lower? I thought this was a good one Its not adjustable. It's a digital one.
Any input on the hot and melted plug?

 

Ok, on the lowest scale (200 ohms), 0.7 is acceptable for internal resistance. It would stand to reason that you would see 0 on the higher scales, perfectly normal operation.
Touching the two leads together should make the meter read out to zero (exception is the lowest scale, which probably won't if it is a very inexpensive unit, but this is ok). Remember, when doing a resistance test, you are passing voltage from the meter's battery out of one lead, through what ever conductor your measuring and back through the other lead. The meter shows a representation of how much voltage made it back through the load. This voltage is not high so do not worry about blowing up anything important, usually in the millivolt range. So picture this, you touch the leads to a conductor and the conductor "conducts" the voltage between the leads, completing the circuit. Now, as you have noted, when the leads aren't touching one another, there is no continuity. Thus when you read no continuity on a wire, there is an open circuit there and nothing is being conducted. Simple, right?
You meter is not hosed, you just need to learn about how to use it.
I have a very simple solution.
http://www.forrestmims.com/
"Getting Started in Electronics"
Best beginners book I've ever found and used.
It will show you how a meter works, how to use it and so much more.
Radio Shack sells the book by special order as well.

As for your connector, this question pops up rather frequently since the problem is common. Check out "melted connector" on the search engine.
It is one or more of the following three problems:
1. Rick Massy (bless him for he gives selflessly) has pointed out time and again how very important it is to check your alternator brushes. This cannot be stressed enough. (look up "alternator brushes") If they are too short, it will screw up your current output.
2. Corrosion. Twenty plus years ago, our machines were built with new wire that was not protected against corrosion. Moisture in the air will cause this to happen, you don't have to have dunked the bike for this to occur. It covers the outer layer of the conductor strands and builds up resistance slowly over time. It cannot be salvaged, only a new harness or wires will fix this problem as the moisture wicks itself up under the insulation and throughout the length of the wire.
3. Poor connections. If your connectors are corroded, this will also build up resistance. More resistance, more current needed to overcome this issue. Result is a hot wire that melts everything attached to and near it. Loose connections will cause this issue as well.

In short my electronically challenged friend, you have a tiger by the tail and, with a little knowledge, you will best him! Tally Ho!

 

Re: Help diagnose xj so owner won't give up hope on a great

Ok, I checked mine tonite.

The white wires measured 0.6 ohm all around on mine.

I wonder how you are getting the leads onto your connector? I cut the plastic away from a pair of 1/4" insulated male quick disconnects to make adapters for the test leads. (See photos).

 

Re: Help diagnose xj so owner won't give up hope on a great

Understanding and learning resistance measurements is quite hard for a new person at using a multi-meter, don't feel bad, I'm an electrical engineer and have to double think what I'm reading half the time.

An easy test (since the bike will run) is disconnect the 3 white phase wires coming from the stator. Put your meter on A/C volts, and test each of the 3 wires (from each wire with the red lead, engine case or ground with the black lead), start the bike and let it run on the battery, each one of the white wires should be putting out around the same A/C voltage, if 1 is dead, your stator needs replacing and its why your D/C voltage in the bikes running system is low and your battery's dying in a short amount of time.

This will be easier for a new person doing this troubleshooting to test the stator then understanding what you should be seeing in ohms resistance.

Good luck and keep plugging away, by the way that Maxim is absolutely beautiful, don't give up on her !

 

I THINK we have solved the charging issue. Went for around a 75 mile ride Sunday. Brought the multimeter along and kept an eye on the battery. Charging at 14.4 or there abouts all day. Keep your fingers crossed. All we ended up doing was rewiring the stator wires with three single connectors, as we could not find a replacement plug locally. At first it still wasn't charging very well, but once the battery recovered, it seems OK
Thanks to everyone for the help! Hopefully it continues to charge and has no further problems.

 

Re: Help diagnose xj so owner won't give up hope on a great

Well it's good to hear you may have fixed it, however the reason that plug melted in the first place is worrying me. Perhaps the plug itself was bad and melted and you will be fine, but definitely keep an eye on it for a while.

Good luck.

 

Re: Help diagnose xj so owner won't give up hope on a great

i owned a 85 v65 magna....honda.....it had a 3 wire connector behind the right side panel that would corrode....heat up and evntually melt and leave yu scarued. the wires went to the stator. only fix was to replace connector and wait for it to happen again or get rid if the connector and solder the wires together. i chose the latter. now there is a kit on ebay just for that problem. i found it by accident when i put my bike away for the season as disconnecting the connector was neccsasary for battery removal. dang thing was melted together like cheese. i got lucky.
this is a great post with great tips and info..

my philosophy is ....yu have no idea what the previous owner has done to yure bike......so be prepared for anything and dont give up.....friggin wires on these old bikes run all over the place and checkin every flippin one of em will give yu an idea of what has been replaced.....and what kind of idiot replaced it.

i think yu fixed yure gremlin....nice bike by the way...creampuf

 

Re: Help diagnose xj so owner won't give up hope on a great

which is exactly why I put dielectric grease in all the connectors once every year or so.