Reg/rec

[Guest]

I was wondering if i can get some help.I have a 84 gs750(Canada Model).My wires on my stator came apart and i had them fixed.I noticed that my voltage was showing 15.2 at 2500 rpm on the reading.I understand i don`t want anymore then 14.8 at 2500 rpm.I replaced my old Honda REG/REC with a new Honda and i am getting the same readings.Do you think my ignition module could be causing this. I asked a bike mechanic and he said that could be causing the spike?????.Any ideas and help would be great.

[posplayr]

sounds like the sense wire is not connected or it is hooked to something being pulled down. Temporarily connect the sense directly to the battery and see if that helps. Report back

[rotty]

Sorry i don`t know what wire that is?.I hooked everything up the same way as it was.Maybe it has been doing this from 2 years ago?.

[rotty]

is the sense wire the wire that is going into my fuse box?. it was a added wire when putting the honda reg in?

[Steve]

Most (but not all) Honda regulators have six wires. Three are the input wires from the stator, one is the output to the battery, one is a ground. The sixth wire is the 'sense' wire, it is connected to something that is switched with the ingnition. Many of us 'T' it into the tail light circuit because the tail light goes on and off with the key. However, if you have some bad connections in the tail light circuit, voltage will be a little low on that wire, which will make the r/r think it's low everywhere, so it boosts the voltage. The best solution is to have a relay that is switched by the tail light, but then runs voltage directly from the battery to the sense wire. It appears that in your case, the sense wire is the wire going to the fuse box. That is OK if there are no problems and the voltage at the fuse box is actually the same as the voltage at the battery. Again, dirty connections wreak havoc on an electrical system.

.

[bwringer]

The three yellow wires go to the stator in any order, the GREEN wire is the ground, and the BLACK wire is the sense wire -- it goes to a SWITCHED POSITIVE (a wire that is only live when the key is on -- many people use the oil pressure switch wire.) Red is +12V, as you would expect.

Lots of people get confused and hook the black wire to ground, but if you do that, the R/R won't limit current. Green is the ground, like in house wiring.

[bwringer]

And stop going to that mechanic. That's the most idiotic electrical theory I've heard in a long time.

[spyug]

If you look up any of my recent posts on charging issues you will see that a lot of my problems came down to dirty or corroded contacts and connectors.

I have the stock charging system on my 83 750 and before cleaning things up was getting 14.5+ volts from idle up to about 3500rpm. After clipping off the old connector to the R/R and putting on new spades along with thoroughly cleaning all of the other contacts, I was able to restore normal charging.

I would agree that your sense wire may not be properly connected but also a) clean or replace contacts b) run an additional ground lead from the R/R ( green line as mentioned) directly to the battery negative.

I would also suggest, when you have time, to wire in a voltage meter to keep tabs on things as you ride. A cheap early warning device in my mind. I use small analog meters from Princess Auto, under $10. Not highly accurate but good enough for government work.

Good luck.
Cheers,
Spyug

[rotty]

Thanks for all your help.I will clean it all up.

I didn`t go to the mechanic and pay him to find the problem.I asked him if the reg he sold me was any good.Thats when he said it could be the ignition is all.

I will run another ground to the neg batt and see if that clears it up.I will run the sense wire to another place rather then the fuse box as it was when i had it done the first time.

[Steve]

To add a note, check your new sense wire location voltage to battery (-) and compare it to your battery volts across the terminals. They should be *very* close, else choose another location, or better yet, fix the connectors and grounds...

Blatantly copied from post #5 ...

... The best solution is to have a relay that is switched by the tail light, but then runs voltage directly from the battery to the sense wire.

.

[rotty]

I cleaned up the connections today and added another ground wire to my neg batt post.I am going away for a week so i will move the sense wire when i get back.I did the voltage check.Thanks for all who helped me with that.My batt and fuse box where the sense wire was is way off.I think that will be my problem.

I will let you know when i get back if all this stuff you have helped me with worked.

[posplayr]

Blatantly copied from post #5 ...


Originally Posted by Steve
... The best solution is to have a relay that is switched by the tail light, but then runs voltage directly from the battery to the sense wire.


.

Another reason for a coil relay mod if you are a Honda R/R owner (use the relay out as sense)

[alke46]

I was advised by duaneage to connect my ground (green) wire to the bike frame instead of the battery (-). It worked for me.

[duaneage]

I found the ignition switches on many GS bikes to have dirty contacts inside that drop voltage. Cleaning the electrical contacts with a cleaning spray is a good idea. I took a 650L from 9.5 on the coils to around 12.5 on battery alone by cleaning that switch. Access it from underneath or remove it completely to grease the mechanism as well. It rides up front and may have thousands of miles of crud inside.

If your lights and accessories are suffering from low voltage, identify the cause and correct it. It could be dirty fuses, bad connections in the white connectors used throughout, or questionable ground connections. There are a number of black wires with white stripes hooked to the frame, make sure they are in good shape.

Using relays to provide more power to certain devices certainly accomplishes the goal but I think it better to provide proper voltage to all the components. The bad connections generate heat, melt connectors, and can even start a fire in extreme cases.

I replaced most of the old ring terminals on the grounds and replaced the old brass bullet terminals with new alloy bullets. I ran new wires to the tail lights since being under the fender they were pretty trashed. I also cleaned the coil mounting bolts to provide a good ground for the ignition coils, the spark plugs appreciate a clean return path to the coils.

Orange is the usual color of 12 volts switched power on the GS after the fuse box.

[spyug]

For cleaning contacts and especially contacts stuck in plastic connectors I found dunking them in a bath of Tarn-X jewellry cleaner to be effective. I was watching a science program on the tube the other night and they suggested a bath in household lemon juice has the same effect and is cheaper. They also mentioned that molasses has the same properties ( although sticky) and in a pinch you can use coca-cola or other fizzy pop. Apparently the pop gets its scouring power from some mild acid thats in the concoction.

Just thought you might like to know.

Let us know how things work out.
Cheers,
Spyug