Charging system on the blink

[MAXIMAN]

My system is not charging. I've checked the stator and rotor resistance they seem ok.

Here's the deal:

When the bike is cold it's charges and the tach works fine. But once the bike warms up the tach quits and the voltage drops to 12 or less. This happens at the same time.

Regulator/rectifier? Ideas?

[Pat Kelly]

My guess is the stator windings. When they're cold they arent touching but when the engine warms up the windings expand and short-out.
Try testing the stator when the bike is warm. Pull the connector from behind the fuse panel and test it on the bike.

[prometheus578]

"Physician, heal thyself..."

Gurus asking for help in the open forum... that's disgracefull!
(Maximan...when Gurus have troubles, we're supposed to PM each other for advice, lest the "little people" catch on that we don't know what we're talking about half the time)
Pat's correct.
Also could be a thermal breakdown of the R/R as it heats up.
Do the feeler gauge check to see if the coil is still "magnitizing"(meaning the windings are good and not breaking down) and that the problem lies elsewhere.
Swap in a spare R/R.

[prometheus578]

"The missing link."

I stole this from a link on Geezer's homepage years ago.
Have used it with great success for years.
Nice step by step diagnostic proceedure.
http://www.electrosport.com/electros...t_finding.html

[MAXIMAN]

Re: "Physician, heal thyself..."

Originally posted by prometheus578
Gurus asking for help in the open forum... that's disgracefull!
(Maximan...when Gurus have troubles, we're supposed to PM each other for advice, lest the "little people" catch on that we don't know what we're talking about half the time)

Hahahahaha...ooops

I'm sorry... I panicked...I did not know what to do as I'm supposed to leave for TeXSIve in a couple days. Add to that I've been with this problem for several days and I just lost my abiltiy to reason as a GURU... I know I'm being a bit of so I'll cool it now.

But ya gotta know Prom...I'm not a real GURU...only of mods not repairs.

I'll check it out and letcha know. I've got a Geezer RR headed this way. Hope it gets here before Friday.

[skids]

1. To check the field coil just turn on the key and use an iron object on the alternator cover. There should be a strong pull. If not, it could be a bad connection to the field coil or a bad VR.

2. If the field coil is OK, When it is acting up, with the seat off and the tank out of the way, check the running volts into the VR at the clip for each of the white wires with the other meter wire to ground. With most clips, you leave it plugged in and slip a probe in along the wire to reach the electrical connector inside the clip. I think you need to set your multimeter to AC to get a reading. If you have one wire different than the other two and that is showing low volts, you need to move to the next clip behind the fuse panel and do it again. Check for arc burning/melting of the connectpr clip.

[skids]

OK, All bets are off. I see you have an XJ from your other posts. I know nothing about that charging system. Fugetaboudit.

Originally posted by skids
1. To check the field coil just turn on the key and use an iron object on the alternator cover. There should be a strong pull. If not, it could be a bad connection to the field coil or a bad VR.

2. If the field coil is OK, When it is acting up, with the seat off and the tank out of the way, check the running volts into the VR at the clip for each of the white wires with the other meter wire to ground. With most clips, you leave it plugged in and slip a probe in along the wire to reach the electrical connector inside the clip. I think you need to set your multimeter to AC to get a reading. If you have one wire different than the other two and that is showing low volts, you need to move to the next clip behind the fuse panel and do it again. Check for arc burning/melting of the connectpr clip.

[DiverRay]

Maximan,
Check your BRUSHES!!!! Your charging system uses a set of brushes, like a car alt. They are probably worn, and need replacing. Don't forget to clean the armature before installing the new brushes.

[prometheus578]

Skids...

1. To check the field coil just turn on the key and use an iron object on the alternator cover.

That's what I meant by "the feeler gauge test(though I do have some brass feeler gauges)

[webbcraft2150]

Re: "Physician, heal thyself..."

[QUOTE]Originally posted by prometheus578
[B]Gurus asking for help in the open forum... that's disgracefull!



Ho boy!. This could be a reason to add another rule concerning the distribution of beverages at XSsive rallies. I think you could loose a stripe for this one.

[DiverRay]

Now Now, we can't know EVERYTHING!!!
Maximan is good at some things, but as he is a rockhead, the electrical will sometimes confuse him. I'm just supprised no one else asked about the brushes! I own a '78 and a '79, so I've not really worked on the XJ, but I still read and remember they DO have brushes.
We all need to try and help each other, and remember, we can ALL be correct SOME OF THE TIME, but NOBODY is correct ALL OF THE TIME.

[MAXIMAN]

Just FYI - I put new brushes in the Generator about 30 days ago. They still look good. Not cheap either. $30 bucks each X2! And Yamaha recommend replacing them every 10,000 miles which for me works out to be about every 6 to 8 months.

Webb

As far as losing a stripe...I've lost stipes around here for a heck of a lot less!

[MAXIMAN]

Well I got my hopes up for a minute only to have them dashed
into the rox!

I tried the feeler gauge magnet test and it passed. So I unplugged the stator and started the bike to see how many volts AC the stator was putting out on each leg. Leg one was 23 v. Leg two was 24 volts. Leg three was DEAD!

It would appear the stator is shot. Whaddaya think?

I'm still getting an upgraded RR from Geezer.

[skids]

My bets are on a bad connection.

Hmmm a brass feeler gage. Those things would tend to get thinner the more that you use them as feelers. Yeah, you did hit that tech tip and I hijacked it. I am sorry.

[trbig]

Hey Maximan...

I'm glad you said that money really wasn't an object to you.. because you can order the brushes from Partsnmore for 5 bucks a piece..

I don't even know where to get a stator rewired. The guy I got mine done from last year doesn't do them any more... and hasn't as of yet replied to my emails trying to get the "Warranty" coverage he promised... since it isn't working any more. Best bet is still Ebay as far as I know.
I was watching a local shop rewind some electrical motors... don't know the ins and outs of it, but from what they were doing, it didn't look much different than these stators?

Tod