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General Category => Yamaha FJ1100 / FJ1200 Running Problems => Topic started by: Waiex191 on April 02, 2026, 10:00:34 PM

Title: Transpo regulator but still high voltage
Post by: Waiex191 on April 02, 2026, 10:00:34 PM
Hey guys,
Just finished connecting my adjustable VR as per the directions here. Unfortunately I'm still getting over 15 volts, even with the pot adjusted to the stop. I tried adjusting it the other way and saw over 16V. Any ideas?
Title: Re: Transpo regulator but still high voltage
Post by: red on April 02, 2026, 11:35:06 PM
Waiex191,

Okay, this is not likely, but you should try another Voltmeter and see if the reading is the same. If you get two different results with two different meters, you will need a third meter to say which one is wrong.
As always, check that wiring connections are clean and secure, especially the grounds.
Discharge the battery until it shows a lower Voltage, then connect the battery and check the charging Voltage.
You may have an odd battery problem. Auto parts stores can load-test the battery for you, usually for free. HTH.
Title: Re: Transpo regulator but still high voltage
Post by: Waiex191 on April 03, 2026, 12:08:48 AM
Red,
It's a new battery. I put it on the trickle charger a week ago, and pulled it off the next day. Rode the bike a little. It showed about 12.8 when I first turned the key on. After starting and running at 3000 RPM or so, it showed 15.5 until I turned it down to the stop. Then it was 15ish. I've got a few meters and can check.
Title: Re: Transpo regulator but still high voltage
Post by: mike g on April 03, 2026, 05:22:22 AM
there was a thread on here about this, but to summarise the voltage sensing wire takes its reading via the ignition switch, which given the age drops the actual battery voltage by at least half a volt or more depending how worn the contacts are. trick is to connect the battery direct via a relay switched by the old sensor wire so the generator gets actual battery voltage. I did it a few years ago and now seems to charge ok. used to eat gel batteries or dry out wet ones every few years.
Title: Re: Transpo regulator but still high voltage
Post by: Waiex191 on April 03, 2026, 02:00:46 PM
Thanks Mike, I searched for that on the forum and have a couple more things to look at.
Title: Re: Transpo regulator but still high voltage
Post by: 81Delorean on April 04, 2026, 06:48:30 AM
I had a similar experience when I did the VR mod to my bike last year. It worked good for about a week and then started overcharging again. Turned out to be a bad VR. I swapped it with another one and haven't had an issue yet with it since.
Title: Re: Transpo regulator but still high voltage
Post by: Waiex191 on April 04, 2026, 08:06:34 AM
Quote from: 81Delorean on Yesterday at 06:48:30 AMI had a similar experience when I did the VR mod to my bike last year. It worked good for about a week and then started overcharging again. Turned out to be a bad VR. I swapped it with another one and haven't had an issue yet with it since.
Thanks!  I do have another on the way.