GT550 charges well when cold but stops charging when hot.

[Suzukidave]

http://www.3cyl.com/mraxl/gt/manuals/gt ... 550-49.htm" onclick="window.open(this.href);return false;

[rbond]

Have you checked or replaced the voltage regulator or rectifier? Electronic parts have a tendency to act up when they warm up a bit.

[Ebayru]

SuzukiDave: Thanks for the manual link. I have manuals, but they all are a bit different so another version is helpful.

Rbond: I have 3 regulators and I'm using the only one that's totally within spec. I have 2 rectifiers and both are in spec. There is not difference in function regarding the problem with either one installed.

I'm in the process of going through the wiring again, making sure all connectors are clean and reconnecting them using a dielectric grease on all contacts. I am rechecking all grounds, cleaning them again and reconnecting again. I'm also going to run it again after all this is done with the regulator cover off (not on the road) just to see if the contacts are doing what would be expected before and after the charging drops off. I will recheck the unregulated voltage again, too. Of note, it's interesting that the manual says to check the unregulated voltage with the system cold. It seems to imply that a difference is expected as the system heats up.

I'm also swapping out the turn signal flasher and the starter relay "Just because" at this point since I have them and they are cleaner units. The currently install flasher seems to stick once in a while (which could also be a intermittent bulb contact.)

BTW, has anyone found any information or can tell me from experience what the normal draw is when the ignition is ON? If I put a voltmeter on the battery, the voltage starts dropping quite rapidly when the ignition is in the ON position.

If I still have the problem after all the above, I guess I'll swap the stator since I have another of those even though the current one reads normal when the system is not charging. At that point I'll be abandoning logic and resorting to magical thinking.

[Suzukidave]

I thought i would post that repair page when i saw the tests and measurements for the charging system . I remember at one of the Deals Gap meets one of the Kawasaki guys had a charging problem that was like yours , it turned out to be a short in the Alt windings .

[Ebayru]

It appears that I'm back to the alternator. The output is not even close to what it should be with the voltage regulator bypassed. I could almost run without a regulator as it won't go over 16v with the lights off.

I guess I'll now install my replacement stator and hope that's it. When the stator's resistances didn't change after it was hot and the system wasn't charging, I assumed the stator wasn't the problem.

[Ebayru]

Now it appears it's the rotor. It's out of spec. The resistance between the slip rings is less than 1 one ohm. There appears to be a short between the slip rings and the shaft and/or the e-magnets with the stator assembled, but not with the stator off which doesn't make apparent sense to me. I'm waiting for a replacement rotor.

The upside of all this is the wiring has been gone over and I've been cleaning and painting other things as I've been going through the bike so it's getting prettier.

[Suzukidave]

When checking the resistance of the slip rings did you have the brushes off the slip rings as this will show a ground as 1 of the brushes are grounded ? Also check the green wire going to the one brush and make sure that it isnt grounded where it is attached to the brush .. this is easy to do if the parts are not stacked correctly and the green wire is touching the screw that holds on the brush .

[Ebayru]

Suzukidave,

Thanks. You've explained why the slip rings seemed shorted to the shaft and e-mags with the stator on but not when off. The resistance between the slip rings (less than 1 ohm) was the same with the stator on or off, however.

I will now check the green wire hookup and see if it's correct.

[Ebayru]

The green wire to the brush was correctly assembled so I'll wait for the rotor to arrive and see if replacing the rotor solves the charging problem.

[Suzukidave]

Well .. this is all good in a way as now you sure know what it isnt

[Ebayru]

Staying on the sunny side of life......

[Ebayru]

And the culprit was ........ the ROTOR..... That was it. It even charges at 1200 rpm now (with the lights off). It wouldn't do that before. The slip ring resistances were 5.5 ohms on the replacement rotor. I ran it for a long time on the stand and then went for a ride and the charging stayed strong.

Thanks to all for your help. This is a great board.

Shel

[Suzukidave]

Thats Great ...Dont ya just love it when the problems are easy

[Ebayru]

Sure.... But the other tasks completed were necessary to the ultimate solution, too. Connectors had to be replaced, others cleaned and coated with dielectric grease. It never bothers me to do these tasks as long as the problem is ultimately solved and I learn something along the way. I certainly learned from this job.

Now I can ride without fear of being stranded.... at least from a dead battery.

[Suzukidave]

I was jokeing just a bit as i remember all you went thru to find the problem.