alternator issues

[RodsWing]

i bought a used 1999 gl1500a goldwing with a moto trike kit on it. on my first long ride, about 4 hours in, the speedometer started flashing, lights started flashing, motor lost power and it died. after 10 min. it re started and ran a mile or so then did it again. i replaced the battery and tested the alternator, it was only putting out 10 volts. i replaced the alternator with a 90amp and it put out 14.4 volts. the bike ran great. the next 4 hour ride... the same thing happened..... any idea where or what to start looking at? the new alternator is now putting pout less then 12 volts.

thank you in advance

[MikeB]

It would appear that you have a defective alternator and need to return it for a warranty replacement or a refund.

[Swagonmaster]

While it does look like you are in need of another alternator keep this in mind; if there is something that is drawing a lot of power that device will soak up the majority of your charging current sort of like a black hole and make your tests mislead you. Just for grins remove the 35 amp fuse that in the starter relay next to the battery. Everything goes through that fuse so pulling it will remove everything except the memory fuse that powers the keep alive memory for the clock which shouldn't draw enough to matter. After that check the voltage output at the rear of the alternator so as to make sure that poor wire connections aren't adding to the problem. This fairly recent conversation also refers to an inexpensive way to check the current draw and some of the problems that poster faced.

viewtopic.php?f=6&t=65583

[RodsWing]

am i pulling the wishbone fuse or little one on the solenoid? do i start the bike before i pull it? thanks to everyone for the input!

[Swagonmaster]

Looking at the wiring diagram again shows me that I am full of hot air on this one. By the time you got enough fuses disconnected to tell you anything the engine wouldn't run and you couldn't test the output of the alternator. So I guess taking the alternator off and take it to an alternator/starter shop and letting them test it would be the best and they often will do that for free. At least like that if replacement is needed you can tell the seller that the alt was tested and is really defective and if it tests ok then you can get a lesson on charging system diagnosis and we will procede.

[RodsWing]

while waiting for an alternator.... it has crossed my mind that when i got my trike the starter button had problems and the cruise did not work. i had the switch replaced at a local shop and they were working find. both times the trike has quit the cruise was on. and now you have to keep tapping the starter button to get it to start. could something in that area draw enough to short out the alternator? maybe something loose where it connects to the starter?

[gford]

Tapping the starter button to get it to start more than likely means your switch is dirty and the copper contacts that sit on a spring inside the switch are not doing their job and are not making a solid contact with the proper posts.

[gford]

Just noticed that you had a new switch installed so it should be working properly.

[RodsWing]

i am looking for loose connections now. i hate to miss beautiful riding days but i walk with a cane and being stranded is no fun....

[Swagonmaster]

Since it is not uncommon for the starter relay to quit I might suggest using a test light on the terminals at the starter relay to see if you are getting current to the relay at all. Doing that would also check the starter button and connections since if it's getting to the relay it has to be working. Use a test light not a voltmeter, the brightness of the light can tell you something about how much juice is getting through not just is there some voltage there. As to the cruise issue, I sometimes have a problem setting the speed because the little microswitch at the front brake lever isn't closing. Try just pushing the handle outward and see if it helps.

[Swagonmaster]

Note to self: read what the man said before you comment!
I see that the cruise is working now and it's unlikely you could have a short circuit bad enough to hurt the alternator and not have it take out some fuses first so that should be ok there. I have heard that poor grounds can be a hard to find problem so you might consider that also.

[RodsWing]

i have looked all over for a short in the wiring and can not see anything. i am thinking of replacing the wishbone fuse with a regular blade style fuse and add an in line fuse to the other wire on the alternator. My hope in doing this is, if there is something wrong it will blow a fuse, and not the alternator. does this sound good and will it work?

[MikeB]

I really believe that there is nothing in the motorcycle wiring that will cause the alternator to fail. A fuse will open before the alternator would experience an internal failure. So I do not think replacing the style of fuse will help to diagnose the problem. Have you returned the alternator or at least taken it to a shop so they can tell you if the alternator has failed or not?

[Swagonmaster]

At this point I would suggest buying one of the amp testers that were talked about in the link that I posted in my first comment, they don't cost much. You really need to know for sure if there is an excessive draw on the alternator or not and how much. The original alt is good for 40 amps draw but don't ask it to do it for a long time as that is a lot of heat and wear being generated at full charge output, same for your new alt, it should do what it is rated at for a while but the longer it has to work at max charging rate the faster it is going to die. If there is no excessive draw then you may need to run wires long enough to be able to watch the meter while driving to see if the draw only happens then but if there is a ton of draw then remove fuses one at a time till you hopefully find one that drops the charge rate (amperage not voltage, voltage will go up) and then you can look into which ever circuit the fuse protects. Keep in mind that the original alternator should be able to power everything on the bike and for a unit with over twice the charging ability to fail means that either you have one whopper of a draw or bad alternators.
As to your question about using inline fuses, It would be better to test rather than mickey mouse it but if you have to I would leave the dogbone fuse alone and add a fuse to the main wire from the alternator that is white but realize that wire feeds the fuse box and 4 15 amp and one 10 amp fused circuits and whatever is possibly taking out the alternator isn't blowing a fuse so I don't know if an extra fuse will help unless there is a partial short in that white feed wire to the fuse box and then an extra fuse might be a help only in diagnosis.

[RodsWing]

i have the new alternator and have installed a voltage meter. i will get the amp meter as well and do as suggested. i appreciate the help with trouble shooting and your time answering as well!

[MikeB]

Personally I believe the voltmeter is probably all you really need. The amp meter will give you additional information but I don't really think you need one.

[Solo So Long]

Actually, Swag's "bad idea" was a good idea, at least partways.

Disconnect the cable from the alternator, check at the output terminal of the alternator for an internal short.

Disconnect the battery leads (NEGATIVE FIRST!) and check for a hidden short between Positive and the frame.

While you're at it, make sure that there is a clear path for cooling airflow to the alternator. When they heat up, they get glitchy.

[RodsWing]

i installed the new voltage gauge and alternator and i seem to be up and running fine. 13.6 to 13.8 volts. keeping an eye on things a bit more closely. thanks again for all the great information and advice.

Rod