GL1500 Keeps blowing up alternators

[boogeyman]

Hello everyone!
I own a 92 GL1500SE Canadian Edition.
Since owning it 3 years ago, I've replaced the alternator twice, had the replacement repaired twice.
Then, purchased the Hitachi for $450 back in November of 2022 and yesterday IT went making it 5 times that the alt has had a problem.
So I'm wondering why this keeps happening?
I bought the crappy DB Electrical one twice.
Always the same problem - disconnected rotor wire.

On the Hitachi, I attached an extra heavy gauge wire from ground to battery, and from main power to positive battery.
I'm not overloading the alt. It's 90 amps and aside from the standard lights - some in the back changed to LEDS.
It's currently in the shop. I'll find out tomorrow what the problem is.. probably same thing.

I'm thinking that heat may be causing the issue, but why not other wings?
Why do some of these bikes have a problem with this and others don't?

Beats me!
Any ideas?
Thanks!

[Rambozo]

If you search here, you can find a pretty good explanation from a guy that repairs alternators. He actually has a fix for the common rotor failure, but the TLDR is that many of the current rotors use the same flawed winding method. The older Japanese Hitachi is the one to get and just keep changing bearings and brushes as needed and they last forever. The Compufire had a good reputation, but the failure rate on them seems to be climbing, lately.
From the photos shown, the current Chinese Hitachi is nothing like the older Japanese one in terms of quality.
As to why you have had so many failures, part of that is not being able to get a good alternator. You would have to compare heat measurements to another wing to see if there is some reason you are running hot.
You don't have anything that messes with the airflow around and through the engine?
Have you replaced the battery?
Have you checked the charging current when installing a new alternator?
When replacing the alternator, do you always replace the rubber drive dampers?

[offcenter]

Have you changed all the lights to LEDs to lessen the load on the alternator?

[Rednaxs60]

No need to change the lights to LED if the alt is rated at 90 amps. Riders change to a higher amp alternator to accommodate extra components. Cars routinely operate with 40 to50 amp or so alternators without issues. My '85 1200 Limited Edition (fuel injected model) with the external alt mod has no issues with a 55 amp rating, more than sufficient.

The 1500 shouldn't need an alternator with more than factory standard amp rating. I agree with Rambozo, it's an alternator issue, not alternator amp rating.

PM sent.

[samwing1500]

I am going to agree with those that say it's the alternators. I went through the same (4) thing.
If you still have or can find, an original Hitachi and have new bearings and brushes put in, then
you have one that will last. Thats what I did. I do carry a spare (aftermarket) alternator in the
trunk of my trike.
Good luck.

[offcenter]

Same here. I went through two of those cheap Chinese alternators.
Finally found an original Honda Hitachi alternator and that one's been fine.

[boogeyman]

If you search here, you can find a pretty good explanation from a guy that repairs alternators. He actually has a fix for the common rotor failure, but the TLDR is that many of the current rotors use the same flawed winding method. The older Japanese Hitachi is the one to get and just keep changing bearings and brushes as needed and they last forever. The Compufire had a good reputation, but the failure rate on them seems to be climbing, lately.
From the photos shown, the current Chinese Hitachi is nothing like the older Japanese one in terms of quality.
As to why you have had so many failures, part of that is not being able to get a good alternator. You would have to compare heat measurements to another wing to see if there is some reason you are running hot.
You don't have anything that messes with the airflow around and through the engine?
Have you replaced the battery?
Have you checked the charging current when installing a new alternator?
When replacing the alternator, do you always replace the rubber drive dampers?

Sorry for the late response and thanks for responding!
For some reason, I'm not getting notifications.. gotta check my settings. =)

There is nothing impeding the airflow around the engine.
I replaced the battery (AGM) around the same time I installed the Hitachi - which is 120 Amps btw.
I've never checked the current.. just the voltage which appears to be normal at between 13 and 14 volts.
I've never replaced the dampers. I'm trying to determine how they could contribute to this issue. Any ideas? =)

Thanks again!

[boogeyman]

Have you changed all the lights to LEDs to lessen the load on the alternator?

The alternator I purchased is a Hitachi 120 amps.
I replaced the saddle bag lights with LEDs but that was it.
Is there a reason I should change them at all since the alt is able to handle high current?

Thanks!

[boogeyman]

No need to change the lights to LED if the alt is rated at 90 amps. Riders change to a higher amp alternator to accommodate extra components. Cars routinely operate with 40 to50 amp or so alternators without issues. My '85 1200 Limited Edition (fuel injected model) with the external alt mod has no issues with a 55 amp rating, more than sufficient.

The 1500 shouldn't need an alternator with more than factory standard amp rating. I agree with Rambozo, it's an alternator issue, not alternator amp rating.

PM sent.

Thanks for responding!
This alt is 120amp Hitachi.
Just got it back today and was told it was the rotor - again.. just like the others.
Got it repaired, but am now afraid to put it back in.

I was thinking it's the heat that's destroying them.. but why not other 92 GL1500s?
I know it's a known problem, but why do some last forever, and others end up like mine?

Should I just remove the left side cover? I don't want to, but what else can I do?
I don't want to spend $1000 per year on alternators.. so far over $1500 spent on this issue.

Thanks again!

[boogeyman]

I am going to agree with those that say it's the alternators. I went through the same (4) thing.
If you still have or can find, an original Hitachi and have new bearings and brushes put in, then
you have one that will last. Thats what I did. I do carry a spare (aftermarket) alternator in the
trunk of my trike.
Good luck.

Thanks for the response!
This is what I have. Hitachi 120amp.
I was told it was brand new, looks brand new, and lasted far longer than the others.
But the same thing happened.

[boogeyman]

Same here. I went through two of those cheap Chinese alternators.
Finally found an original Honda Hitachi alternator and that one's been fine.

This is what I have. Hitachi 120amp.
I was told it was brand new, looks brand new, and lasted far longer than the others.
But the same thing happened.

Thanks!

[Rambozo]

I've never replaced the dampers. I'm trying to determine how they could contribute to this issue. Any ideas? =)

If the dampers are hard, there will be excessive vibration which can crack the rotor windings, among other things.

[gford]

I went through 5 aftermarket alternators before I bit the bullet and bought a honda OEM 40 amp alternator from the dealer. No problems since installation although I still carry a spare in the saddlebag just in case.

[WingAdmin]

I've never replaced the dampers. I'm trying to determine how they could contribute to this issue. Any ideas? =)

Thanks again!

There's your problem. Those dampers should definitely be replaced. Age and heat causes them to get very hard. Their job is to dampen the power pulses generated by the engine every time a cylinder fires, to reduce the acceleration/deceleration transmitted into the alternator associated with each pulse - basically, reduces vibration. That vibration is awful to the rotor, and can cause the delicate windings (or their connection terminals) to break.

Anytime you replace an alternator, the dampers should also be replaced.

[boogeyman]

I hope you are right!
Does anyone have a spare set they can send me?
I'll look online in the meantime.
Wish me luck!

Thanks a bunch guys!

[Rambozo]

You need four. 13534-MN5-020
https://www.partzilla.com/product/honda ... c0daddd951
https://www.mrcycles.com/oemparts/parts ... 34-mn5-020
https://www.bike-parts-honda.ca/honda-m ... 3534MN5020

[boogeyman]

I ordered them today from PartsZilla.
$40 including shipping.

Thanks a bunch!

[boomerang]

Re Output: We had alternators on semis that put out 120 amps. Mind you they were a lot larger than what's on the 1500's. First alternator was replaced at 70,000 miles with a factory dealer replacement (10 years ago). After 50,000 miles it is acting up (Thank you voltmeter that I installed). This winter I will be doing a lot of maintenance. One item will be to get the alternator rebuilt. I do not trust after market alternators.

[offcenter]

I do not trust after market alternators.

After my experience, I don't trust 'em either.

[pocketchange]

40 amps are more than enough. Rebuild it yourself. Replace the bearings & whatever else w/THE RUBBER CUSHIONS.
ALL the misc. rubber is at least 24 YEARS OLD and NOTHING lasts forever. (PS, learn your way around your ride). pc

[Wildwilly018]

I put in an alt 41/2 yrs ago I got on Amazon and it is still going strong. Just the normal 40 amp one. Might look into changing my dampeners tho if I can find some here. Never changed them.

[MikeB]

I put in an alt 41/2 yrs ago I got on Amazon and it is still going strong. Just the normal 40 amp one. Might look into changing my dampeners tho if I can find some here. Never changed them.

Cyclemax has them. About $25 for a full set plus shipping.
https://cyclemax.com/products/gl1500-al ... s=e&_v=1.0

Or Ebay for $21.28 plus shipping and sales tax for a set of four.
https://www.ebay.com/itm/364101988731

[Wildwilly018]

I put in an alt 41/2 yrs ago I got on Amazon and it is still going strong. Just the normal 40 amp one. Might look into changing my dampeners tho if I can find some here. Never changed them.

Cyclemax has them. About $25 for a full set plus shipping.
https://cyclemax.com/products/gl1500-al ... s=e&_v=1.0

Or Ebay for $21.28 plus shipping and sales tax for a set of four.
https://www.ebay.com/itm/364101988731

Thanks Mike. Cyclemax is 36 buck US. About 50 bucks canadian plus shipping.

[Fuzzyswing]

Is there a place that rebuilds alternators
I have a oem that quit charging.

[Rambozo]

Many local auto electric shops will do the 1500 alternator as it is basically a car unit with just a different drive.