Possible Electric Problem

tedkraus · April 17, 2012, 08:04:40 PM

So I sold my bike, but my friend has not paid me yet... So I have continued to ride her while awaiting payment. Anyways I was getting home this evening and revved the bike pulling into my garage, noticed the lights got dimmer instead of brighter. So I am thinking something is not working right and the bike is running purely on battery since when you rev the engine the lights just keep getting dimmer. It starts idles runs fine, but I am afraid of a charging problem. Could this be regulator/rectifier? If so how to confirm?

hootmon · April 17, 2012, 08:32:55 PM

Regulator issues are very common on Magna's... Take a volt meter and attach it to a voltage point... At idle you should have around 12-13 volts. Now rev the engine to 3000 RPM. You should have 15+ volts... If not, it's most likely the regulator...
Search the site for "shop manual" or search the internet for s.m. Honda Magna. You can down load the manual and there are instructions on testing regulators and stators..

LIMagna · April 18, 2012, 06:19:50 PM

Hoot's right on ... the RR can fail one of two ways. Some have had it overcharge and cook their batteries and electrical system or it can undercharge, which is the way mine went. The problem got worse as the bike warmed up or as the rev's climbed. Put a voltmeter on and check to be certain but it does sound like that could be the issue.

tedkraus · April 20, 2012, 03:20:07 PM

It might be under charging, or it could be my wild imagination, since I sold her to a good friend and want to be honest and 100% about anything going on... I put a voltmeter on her 12-13 at idle, and she started climbing in voltage over 14volts while revved (could be my old meter is slow if this is supposed to be instant). I am gonna ride her to my friends house today about 200 miles away. So we shall see. Thanks guys!

TLRam1 · April 20, 2012, 04:18:11 PM

Your sounds fine, in the 14 range while it's running in the 4-5K RPM range is what it should be. Maybe your regulator is working sporadically.

hootmon · April 20, 2012, 05:09:43 PM

Quote from: TLRam1 on April 20, 2012, 04:18:11 PM
Your sounds fine, in the 14 range while it's running in the 4-5K RPM range is what it should be. Maybe your regulator is working sporadically.

Check the connections under the seat (two plugs)... While I was doing that, I'd put a little dielectric grease on the connections...

Magnum Magna · April 20, 2012, 05:26:15 PM

How old is the battery?
I know batteries should last longer but I am a person that put a battery on borrowed time after 3 to 5 years in Texas that is.

hootmon · April 20, 2012, 05:53:35 PM

Quote from: Magnum Magna on April 20, 2012, 05:26:15 PM
How old is the battery?
I know batteries should last longer but I am a person that put a battery on borrowed time after 3 to 5 years in Texas that is.

2-3 years in Floriduh...

Magnum Magna · April 20, 2012, 06:31:41 PM

I did have one that lasted 1.5 years. I never got that battery again.

tedkraus · April 20, 2012, 07:34:50 PM

I think it might have been a little low from tons of city driving, higher voltage now.. Ran her the 160 miles to my friends house. Im gonna miss the bike. Now the search begins for the next bike & I gotta start saving up. Prolly buy a vfr800 in a year or so.

tedkraus · April 21, 2012, 05:31:22 PM

Quote from: Magnum Magna on April 20, 2012, 05:26:15 PM
How old is the battery?
I know batteries should last longer but I am a person that put a battery on borrowed time after 3 to 5 years in Texas that is.

The battery is 3 years old, not sure of the brand I purchased it at O'reiley auto parts. Although I just want to point out the original battery was 14 years old, and was the original when I purchased the bike... However it was very weak and on its last legs even after being charged....So I quickly replaced it after purchasing the bike.

Imabass · May 16, 2012, 11:41:42 PM

this sounds like a prob that I had on another bike. My issue was the headlight. It was a car headlight and I swapped with a mc light and no more problems. I put the light that dimmed on another bike to confirm that it was the light. I think the light that was dimming could not withstand the higher voltage at 14.5ish.