High voltage from charging system


Information and questions on GL1000 Goldwings (1975-1979)
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pricey1123
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High voltage from charging system

Postby pricey1123 » Mon Jan 13, 2014 10:31 am



Hello, I've had a new battery and a new alternator during my restoration. When the battery is fully charged from a trickle charger it starts no problem but when I come home from a ride out or park the bike up when I press the start button the starter really really struggles to crank like I have a flat battery. So I checked to see if I'm getting voltage from the charging system but I'm getting a really high voltage reading from my voltimeter on the bike and with another meter I used and it's reading about 15.83v - 16v. Could this be giving me the problem? Would it be the regulator/rectifier packing in? I can't see it being the 3 yellow wires because I've read post about them not charging the battery but I may be wrong?

Cheers.



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Re: High voltage from charging system

Postby WingAdmin » Mon Jan 13, 2014 11:55 am

pricey1123 wrote:Hello, I've had a new battery and a new alternator during my restoration. When the battery is fully charged from a trickle charger it starts no problem but when I come home from a ride out or park the bike up when I press the start button the starter really really struggles to crank like I have a flat battery. So I checked to see if I'm getting voltage from the charging system but I'm getting a really high voltage reading from my voltimeter on the bike and with another meter I used and it's reading about 15.83v - 16v. Could this be giving me the problem? Would it be the regulator/rectifier packing in? I can't see it being the 3 yellow wires because I've read post about them not charging the battery but I may be wrong?

Cheers.


If you're seeing ~16 volts when charging, you've got a problem - and it is likely cooking your battery, which is why it is dying and can no longer hold a charge. That's why you find it unable to crank after it's not been on the charger for a bit. Incidentally, are you using an actual trickle charger (bad) or an intelligent float charger (good)? A trickle charger will overcharge and kill a battery as well.

As for the overcharging on the bike, the most likely culprit is the ground wire on the regulator. The regulator looks at the voltage between the incoming wire (from the rectifier) and ground. It uses this to determine how much of the incoming voltage to allow out the output (regulated) side of the regulator.

If the ground has a bad connection, it causes the voltage potential between the input and the ground to "look" artificially low to the regulator. There might be 18 volts coming into it, but because the bad ground (which acts essentially as a resistor) drops that down to, say 11 volts, the regulator thinks; "must increase output to get to 14 volts!" so it cranks up the output. The result is a regulator putting out more than 14 volts, in your case 16.

The solution is simple: Disconnect the regulator's ground (green) wire and run it directly to the battery negative terminal. This ensures a perfect ground, and should fix your problem (assuming that's the cause). If it is still happening after you do that, then the regulator has gone bad and needs to be replaced.

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Mon Jan 13, 2014 12:30 pm

WingAdmin wrote: are you using an actual trickle charger (bad) or an intelligent float charger (good)? A trickle charger will overcharge and kill a battery as well.


Hello, I'm using an intelligent float charger. Couldn't think of the name off top of my head when writing this :lol:

And for the green ground wire is that the one that connects by the ignition coils? Electrics are my weak point so hang on with me if unclear.

Cheers.

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Re: High voltage from charging system

Postby WingAdmin » Mon Jan 13, 2014 12:52 pm

pricey1123 wrote:And for the green ground wire is that the one that connects by the ignition coils? Electrics are my weak point so hang on with me if unclear.


It is underneath the left side tank "electrics maintenance door":


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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Tue Jan 14, 2014 11:29 am

Hello, Been busy on the bike today, I've tried connecting the green wire to the negative terminal on the battery but the voltage still stays the same, I did a little more research last night to see if anyone else had the same problem and another member of the forum says jump the black wire from the regulator to the positive terminal of the battery. Tried that and it worked I've got the voltage down to the highest of 14.6v - 14.7v is that okay? or still a little too high? Also is this safe to leave connected to the battery or would I have to place something into the wiring?

Cheers.

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Re: High voltage from charging system

Postby thrasherg » Tue Jan 14, 2014 12:12 pm

14.6 to 14.7 is great.. Sounds like the black wire from the ignition switch was not doing what it should!! You might need to put a relay in series with the black wire, I believe there is current flowing in the black wire all the time, (which is why it was switched by the ignition) to prevent the battery going flat when the engine is not running. But you do seem to have found the cause.

Gary

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Tue Jan 14, 2014 1:28 pm

What relay would I need? Any ideas? Also do I keep the black wire connected direct to the battery with relay? And would it opperate when the engine is running?

Million and 1 questions but I don't have a complete clue what I'm doing with electrics and don't want to damage anything electrical else I'll be buggered! haha

Cheers.

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virgilmobile
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Re: High voltage from charging system

Postby virgilmobile » Tue Jan 14, 2014 2:42 pm

The black wire is switched ignition.cut it loose from the regulator.Use the harness side to operate a relay,a ground for the relay is needed.
Attach a 5 amp fused wire from the battery to the switch contact of the relay.
The other side of the contact attaches back to the black wire feeding the regulator.
Any generic 12 volt relay will do.
Now when you turn on the key,the relay will click on providing direct battery volts to the regulator.

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Re: High voltage from charging system

Postby virgilmobile » Tue Jan 14, 2014 2:52 pm

This link was on a 1200 but the wiring you need is the same..
viewtopic.php?f=5&t=12522

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Tue Jan 14, 2014 4:33 pm

I'm going to order a 5 pin 12v relay tomorrow, which wire connects where on the relay?

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Re: High voltage from charging system

Postby virgilmobile » Tue Jan 14, 2014 5:12 pm

First,most any auto supplier / junk yard should carry a relay.Its the same kind used for autos,fog lamp switching,fuel pump relay,door lock relay,etc.
I get mine at the junk yard out of junk cars and truck fuse block for a dollar each.
The pins used depend on which relay you get.
It doesn't have to be a 5 terminal one,a 4 terminal one would work too.All it is,is a coil and a normally open switch.
On the relay I used,the middle contact is unused

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Wed Jan 15, 2014 10:41 am

Hello, I'm going to order a new 4 pin relay switch for £5. It states in the description that its: DC 12v, 40amp current.

Will that be okay to use?

Cheers.

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Re: High voltage from charging system

Postby thrasherg » Wed Jan 15, 2014 11:30 am

pricey1123 wrote:Hello, I'm going to order a new 4 pin relay switch for £5. It states in the description that its: DC 12v, 40amp current.

Will that be okay to use?

Cheers.


That is a lot beefier than you need, but it will work just fine.

Gary

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Thu Jan 16, 2014 12:01 pm

Hi, I've got a relay from the shop. Its: 12v, 30amp, 4pin and fused.

Here is a pic of the relay layout for which wire goes where but I don't have a clue so heres my guess at which wire connects where. I have numbered them so you can rearrange/swap them round if I've messed up haha. :lol:

This is probably something simple to do but as you guessed I don't know what the **** im doing!


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thrasherg
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Re: High voltage from charging system

Postby thrasherg » Thu Jan 16, 2014 12:07 pm

No you have it wrong, You need the following connections:-

1 - Black wire originally connected to regulator
2 - ground
3 - To regulator
4 - connect to battery (+ve terminal)

What happens is that when you turn on the ignition, 12 volts will appear on the old black wire that used to go to the regulator, because that is now connected to pin 1 and pin 2 is connected to ground, It will cause the relay to operate. as you turn the ignition on/off you will hear the relay click on and off. When the relay operates, it will now connect the 12 volts from the battery (pin 4) to the regulator (Pin 3) and cause the charging circuitry to operate. We connect pin 4 to the battery as it has a fuse in it, to protect the battery and motorcycle from any short circuits or faults after the relay.

Be sure to insulate all the connections with tape (or better heatshrink) as you do NOT want anything touching the frame and shorting out.

Hope that clears things up.

Gary
Last edited by thrasherg on Thu Jan 16, 2014 12:52 pm, edited 2 times in total.

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Re: High voltage from charging system

Postby WingAdmin » Thu Jan 16, 2014 12:48 pm

Here's the correct way you want to wire it:
.

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pricey1123
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Re: High voltage from charging system

Postby pricey1123 » Thu Jan 16, 2014 2:02 pm

Thats brill will start work on it tomorrow, thank you.

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Solina Dave
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Re: High voltage from charging system

Postby Solina Dave » Fri Nov 06, 2015 3:21 pm

How would you recommend making the connections at the relay? Maybe an appropriately shaped female plug/pig-tails arrangement, or some kind of slide-on connector? Or whatever?

.................................Dave


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