Alternator Brushes

Hi all,

I'm pretty sure that I'm having trouble with my alternator, but I wanted to see what you all thought.

A couple of days ago I tried to start my '85 XJ700. Everything seemed fine until I hit the start button. The gauge cluster lights, neutral light, and headlight went out and all I hear was a click from the solenoid. I attempted a roll start, but didn't quite get it. Then I tried the starter button again and it fired up. On my drive home, I noticed that every time I used the turn signals or hit the brakes the engine would cut out briefly. I was able to get home by keeping my rpms above 3k or so every time I needed to use the brakes. By the time I pulled into the driveway, the problem seemed to disappear. I was able to hit the brakes and turn signals while idling with no trouble.

I have had to charge my battery every 2-3 of weeks because it is slowly losing its charge, so I know that there must already be some issue with the charging system. I did fully charge it just a couple of days ago.

Could these strange events be symptoms of worn alternator brushes? Or does the intermittent occurrence of these gremlins suggest a faulty connection somewhere?


I've read a couple of forum topics that may address this issue here...

http://xjbikes.com/Forums/viewtopic/t=1 ... art=0.html

and here...

http://xjbikes.com/Forums/viewtopic/t=2 ... ushes.html

 

How new is the battery? Your charging system could potentially be working perfect, ut if the battery wont hold that charge, you run into a problem.

 

The answer to your questions is YES. Could be connections or brushes or something else. First of all you must check the battery. You need a good source of power before you can find a fault. You can then check the alt. output. If you are seeing 14.5 volts or there-a-boughts at 3000 rpm the alt is probably OK. If not look at the brushes and check the length. Check all connections paying particular attention to the fuse box. They are apparently notorius for causing problems. Loose or dirty connections can cause all kinds of problems.

 

MSM, the battery is about 4 months old.

 

Try what JFStewart said, put your voltmeter on the battery terminals and see how the voltage changes @ idle vs 3k RPMs. You should be sitting close to 12v at idle and 14v at 3k.

 

go ahead look at the points. easy to do

 

Unfortunately, I can't even get it to start for testing purposes. It is now sitting in a parking lot near where I work.

Last time, I got it home... barely. I just had to keep the engine revved past 3k rpm's anytime I needed to use the brakes and not use the turn signals. Then everything started working again about 4 blocks from my house and I started it up and cruised around a bit the next day. I had to go out of town last weekend, so I didn't have time to test anything then. Being that this is my only mode of transportation, I rode it into work this morning and again, ran just fine. Then on my way home this evening it died as soon as I hit the turn signal.

Here's the order of strange events when it died after the first start attempt and I was able to get it up and running again. Turn on the key and everything seems to be fine. Headlamp, gauge cluster and neutral light on. I hit the start button and everything goes dark. I perform a half-hearted attempt at a roll start and everything lights up again and I'm able to get it started. However, after this point, hitting the breaks or turnsignals will cause the engine to cut out or completely die. (if I'm not over 3k rpm's)

I'll take my volt meter in to work with me tomorrow and check out the battery, but it should be ok. I just charged it a couple of weeks ago and it is only a couple of months old. Could the intermittent nature of this problem indicate a bad connection or fuse issue? Or could this still be a result of worn alternator brushes?

 

I don't know what you mean by a battery being good because it is only a couple of months old and you just charged it a couple of weeks ago. You could have either gotten a defective battery and a battery can be in need of daily charging if there is another problem that prevents it from being properly charged while riding. To say you charged it two weeks ago means absolutely nothing.

With that being said, you need to have the battery checked by someone with the proper equipment. That includes a load tester, then get yourself a proper charger to make sure the battery is fully charged at all times while you are troubleshooting your problem. Since your problem sounds fairly intermittent, you need to methodically start checking wiring, connections, and switches. It almost sounds like you have a bad ground somewhere on the bike or an intermittent short in the ignition system, in addition to a possible regular charging problem indicated by the need to keep the revs up while you are able to get the bike started.

 

taking all the symptoms together, if it's not a wiring or connection problem, (check the big connector off the rectifier) or a flat battery, then I vote STARTER SOLENOID.