GL1800Riders Forums banner

1 - 17 of 17 Posts

·
Registered
Joined
·
685 Posts
Discussion Starter #1
Good Day All,

I have been looking into a problem I noticed this week. I have an aftermarket high output Alternator installed that I purchassed off ebay 5 or 6 years ago. I fixed my Digital voltmeter and noticred the higher voltage. Could have been a problem for a month or so. Was fine in June on 7000 km trip to Newfoundland, then the poor soldering on Chinese voltmeter gave out after 3 years.

- Upon repair of my digital voltmeter, it started showing 15-16.9 V at idle (seems to jump from 15-16.9 at times after total warmup seems to settle around 15.2V - 15.5V). I do see high 14's occasionally.
- meter across battery shows about 0.2 Volts less than the Digital voltmeter, but that can be adjusted later.
- Last night I shut bike down and battery was showing 14.3 volts when key off.
- Just checked this morning and it was at 13.2 V with key off.
- cranking voltage only drops to 11.5 and it starts quickly and bounces right back up to 15 region.
- ECM reset seems to work OK, but still hunting around 750 RPM after complete warmup (fans off/on). (from the wonky voltage it's getting I suspect).
- Bike runs great.
- All lights seem to slightly flicker including dash lights.

I have replaced ALL incandescant bulbs with LEDs. (Current draw much lower now I suspect). I did pull fuses from lights no change. Also disconnected back end via connector, no change. Only non-LED are HIDs in Low beams. High beams are LED.

I am really worried about frying the battery.

Anyone have any suggestions as to where I should start looking ? Wiring to Alternatlor ?? Fuses ? Battery terminals are great shape. AGM battery.
I don't want to get replacement alternator if it is not the culprit.

Thanks in advance for all your help in this ...

Steve
 

·
Vendor
Joined
·
17,780 Posts
Checking a charging system always starts with verifying that the battery connections are clean and tight, and then the battery needs tested. Once a good known battery is installed, only then should the charging system be checked.

Unfortunately just like starters, on 5th gens, the only alternators that consistent reliability are ones that come in Honda packaging. To me it sounds like your alternator is over charging, and that can cause high-voltage issues can show up in various ways.
 
  • Like
Reactions: Art H.

·
Registered
Joined
·
7,552 Posts
Are you checking the voltage with a good handheld type voltmeter or are the voltage numbers from the aftermarket one that has been added?
 

·
Registered
Joined
·
335 Posts
Mother Honda designed the alternator to power the bike in a ton of scenarios and then added about 10% for heated gear, GPS, trailers, etc. High output alternators may make you feel better about the alternator but may be cooking your battery as well. AGM batteries are pretty finicky about charging.
 

·
Registered
Joined
·
1,105 Posts
Not had an alternator problem on my wing, but my Explorer alternator regulator went bad and I was worned it could exceed the acceptable voltages for the truck's ecu. If a second meter confirms your voltages are wrong I'd get that alternator out of there before it causes damage elsewhere.

Sent from my Moto Z (2) using Tapatalk
 

·
Registered
Joined
·
3,350 Posts
Assuming that your voltmeters are accurate, the voltage regulator portion of the alternator has failed.
 
  • Like
Reactions: GLblinded

·
Registered
Joined
·
685 Posts
Discussion Starter #9
I suspected AC getting in there. I will check again with a different meter. A friend may have an osciloscope I can use. If AC getting in then diodes may be shorted.
I wonder if I can buy some diodes at Electronics store. The older Alternator had 4 Diodes. This one has 6 I understand. I put in the newer Alternator last time mine died.
I checked with 3 meters. All show 27.2 volts on AC scale. Even basttery shows 27 volts on AC scale. Think my meters are wonky.
 

·
Registered
Joined
·
685 Posts
Discussion Starter #11 (Edited)
Update: Problems Solved:

Since this was an aftermarket Alternator, when I opened up the alternator I found that there were 8 diodes , not 6 like in 2006 alternator. It is probably an automotive Honda alternator refitted with a good splined rotor.

I remove the Voltage Regulator, VR H2009-119 and called a local repair shop. He had one in stock $50 CDN
Soldered her in, and reinstalled alternator. Now I am getting a steady 14.2-14.4 on ECM reset run.
Looks like the problem with this alternator is dirt buildup and lack of air in that tight little space they jam the alternator into and also additional heat from using an 8 diode car alternator.
Considering putting a muffin fan in that cubby hole to get some air moving.
So my wonky idle, all lights including dash, flickering and over voltage were all caused by a failed Voltage regulator.

Probably saved myself a few hundred today towards my 2020 DCT.

Thjanks all..
Steve
 

·
Registered
Joined
·
685 Posts
Discussion Starter #12
Greg, Looks like was VR - H2009-119 Regulator. I bought one locally and soldered it in. All problems went away.running better now than it has in a few years. $50 CDN. My time and a little solder.
 

·
Registered
Joined
·
2,685 Posts
Update: Problems Solved:

Since this was an aftermarket Alternator, when I opened up the alternator I found that there were 8 diodes , not 6 like in 2006 alternator. It is probably an automotive Honda alternator refitted with a good splined rotor.

I remove the Voltage Regulator, VR H2009-119 and called a local repair shop. He had one in stock $50 CDN
Soldered her in, and reinstalled alternator. Now I am getting a steady 14.2-14.4 on ECM reset run.
Looks like the problem with this alternator is dirt buildup and lack of air in that tight little space they jam the alternator into and also additional heat from using an 8 diode car alternator.
Considering putting a muffin fan in that cubby hole to get some air moving.
So my wonky idle, all lights including dash, flickering and over voltage were all caused by a failed Voltage regulator.

Probably saved myself a few hundred today towards my 2020 DCT.

Thjanks all..
Steve
Good job on the VR replacement, I don’t think a mini fan will help, do you have a belly pan on it? Routing some air from movement down the road would be better than a mechanical devise that can fail on you.
 

·
Registered
Joined
·
685 Posts
Discussion Starter #14
Yes ! Fans can go anytime. I was even considering sharks gills in the covers to vent the heat. Rain may be a problem there. This is probably one of the reasons Honda left the openings on the 2018 around the alternator, to get more air flow.
You have to wonder why they would place the alternator in such an enclosed location. Doesn't make a lot of sense. Especially with engine heat and heat from alternator ! The 8 Diodes are probably part of the problem, in a Honda Car, there is way more air flow under the hood and there is also a turbine cooling blade on many car alternators. This one has a little mickey mouse fan inside the alternator.
 

·
Registered
Joined
·
3,350 Posts
If the temperature of an alternator gets to high, the failure(s) will be a desoldering of rectifier bridge diodes. That solder joint is the most heat sensitive location in an alternator. Some manufacturers have gone so far as to use silver solder as it has a higher melting point. Others have introduced water cooled rectifier bridges on automobiles in an attempt to deal with the combination of high electrical loads and (due to aerodynamics driven body styles) low to nearly nonexistant under-hood air circulation and the high under-hood temperatures that result.
 

·
Registered
Joined
·
685 Posts
Discussion Starter #17 (Edited)
This a Honda Alternator. Problem is it's for a car, modified tpo have spline drive. Good thing is parts are easier to get and cheaper for cars. Like Darkside Altrernator. LOL
I pulled it at 4PM, identified problem and had new Voltage Regulator in my hand by 6PM. $50 CDN $40 US. Had it running by 8PM Perfect Voltage. If I had my old Honda Alternator that blew up, I'd have to wait at least 3 days for parts and wait on hold for an hour when ordering.

I do think the environment where the alternator is located is a Major heat reservoir. Was thinking of putting a CPU Cooling tube 12 V Fan on back of Alternator to suck off heat. Keep the VR/Diodes cool. The automotive Alternators aren't probably designed for the heat, resulting in higher failure rate. Heat kills semiconductors. My alternator has 4 windings and itty bitty fan on the rotor. Full Retail for a Honda Alternator is $874 US + Tax + Labour.
 
1 - 17 of 17 Posts
Top