voltage regulater or rectifier

[lonewing]

which would it be the regulater or rectifier when the volt gauge reads 10v ?

[virgilmobile]

Yes to all including the stator,wiring,corroded connections,bad grounds or even just a bad meter.

Your gonna need a cheap digital volt meter to find out where your problems are.There about $10.

We can describe all the test procedures...there very easy to follow and there's just a few parts involved.

Let us know when you want to start.

[lonewing]

bring on the tests, please

[lonewing]

I also have a powerd multimeter.

[virgilmobile]

First,start the bike ,check the actual battery voltage right at the battery posts.
At 3000 rpm it should be near 14 volts DC.
At the battery,there's 3 yellow wires on a plug.disconnect it and examine for corrosion
At 1000 rpm,there should be near 25 volts AC between any 2 pair of wires.3 measurements,each pair.
At the regulator module,there's a switched 12 volts DC.verify its there.
The diode block.it is 6 diodes.Measure with the analog meter from yellow and then green to the red wire.one direction conducts,the other should not.

[lonewing]

before I get into this, does it make any difference if I have a point type regulater with a dayna tech ignition system or do I need a poinless type regulater?

[virgilmobile]

The charging system is totally independent of the charging system.
Also measurements of the 3 yellow wires are NOT to ground.Just between pairs

[lonewing]

I checked the battery so at the battery it reads 15.45v , the yellow wires are solderd together by the po and I can't get to the bare wire without damaging the wires. I put the old regulater back on and the voltage gauge red about 14.5 till I guess it heated up then it droped to 11.5v, so i'm guessing the other one got so hot it just burned out, what do you think? all your help is very welcome.

[virgilmobile]

I'd be more inclined to believe the 15 volt one is OK and the 11 volt one is bad.
At the regulator,there is a black wire.Its switched 12 volts.Due to aging,there is usually a voltage loss in that wiring.this loss(about 1 volt) shows up as over charging the battery.
I suggest this.Put that on back on.start the bike and attach temporarily a wire direct from the battery positive post and stick the other end in the regulator black wire.
Look at the volts again.Ill bet a nickel that the battery volts drop closet to 14 volts as soon as you make the connection.
If it dosen't,replace the regulator.It can be required for any one from a 80-87 wing too.
If the voltage does drop.There can be a relay wired into the circuit to bypass the jumper wire

[lonewing]

thanks for all the help, I think i'm gonna go with a new regulater.

[virgilmobile]

Stop.a new regulator may not fix the over voltage.Put in the jumper first and verify if it does or does not drop the voltage to normal.
Too often I've seen a wiring age problem and a new regulator works exactly the same way.
Don't throw parts at it and hope.Find out first.
If the voltage stays above 15 volts with the jumpered black wire THEN replace it.

[lonewing]

ok, it just is beyond my experience and i'm afraid of burning out the harness.

[lonewing]

what is the diff between a #25 regulator and 32, this # is found on the face of the regulator

[virgilmobile]

I don't know the difference off hand but ill research it.
You can't burn up the harness.
Both ends are 12 volts.Just don't touch the bare end of the wire to ground.
It's just a test method.
Another way is to use your DVM.
Connect the red wire to the battery positive lug,connect the black to the black wire right at the regulator.With the key off it will show about 12 volts DC.When you start the bike it should drop to less than 0.45 volts.If its above 0.75 volts,the battery is being overcharged.This is a wiring problem.
Also by what you read on the battery,it sounds like your dash meter has the same problems.Poor wiring on the switched side.
There are changes that can be made to improve it.Not costly.

[virgilmobile]

what is the diff between a #25 regulator and 32, this # is found on the face of the regulator

I've had no luck with those numbers....
The regulator # is 31400-371-003

[lonewing]

ahhh, finaly I found the cause it turned out to be the volt gauge. when I tested the battery (key off) I got 12.77v, (key on running)2000rpm I got 15.45v. (idleing) I got 13v.

[virgilmobile]

Just so you know.15.45 volts is a bit high.It should max out around 14.3.
It will boil the battery so until you can get it lower,keep an eye on the battery acid level.
There is a modification for that which uses a simple relay.

[lonewing]

ya, I was wondering about the high volts, I thought the rectifier took care of the iniatial voltage then the regulator did the rest so where could the extra volt be coming from?

[lonewing]

if and it's a big if, the po installed a performance stater, could that explane the extra voltage( for extra lights) ?

[virgilmobile]

Unregulated,the rectified stator output iss well above 15 volts.the regulator circuit simply shorts out part of the rectifier long enough to reduce the voltage.Its called a shunt regulator.
The reason for the little high voltage is because the regulator uses the switched volts(black wire) as a reference voltage.If its below 14.3 volts,the regulator just allows more voltage to come out of it till it peaks at 14.3.
When the black wire has a voltage loss,its brought back up by the regulator.
You can end up with 14.4on it and 15.8 on the red wire.

[lonewing]

thank you I have found this forum to be very helpful. when I can find a jumper wire i'll try the black wire test.