1986 GL1200: how to measure charging current

[MtnMan]

Hello,

I had to replace the rectifier/regulator on my 1986 GL1200 Interstate and also the connector for the three yellow wires coming from the stator. I soldered the wires instead of getting a new connector.

As I don't want to end up stranded again I wanted to check both Volts and Amperes coming from the charging system.

The battery voltage is 13.0 Volts and when the engine is running it goes up to ~14.3 Volts.

The shop manual has a procedure for checking the current: removal of the main fuse, connecting an (analog) volt meter:

I don't have an analog volt meter and tried the same using my digital multimeter and I was not able to start the bike. It looks like the current does not simply flow through the meter.

How can I measure the output current with my meter?

Thank you!
Armin

 

[slabghost]

Current check will require an amp meter. One that encircles the wire.

 

[AApple]

You can easily fry a multi-meter trying to start it like that, with the meter in the circuit. Doing it like that prolly popped the internal fuse of your meter, too....they are normally only rated for around 10 amps.
A current/amp probe is the easiest way, but of course not everyone has one of those.
Here's the best way to do it....
On my 'Wing, I have replaced the dogbone fuse with a spade-type inline fuse. I also have what is called a "Fuse Buddy", that you plug in in place of the fuse. Once the thing is running, you simply press the button, and it displays the amps going thru the fuse. You can get Fuse Buddys from any of the major tool guys(Crap-On, Matco, etc, but you also may be able to find them at NAPA, or any other major parts house. Worth a look.



Looks like Autozone carries them.... :good:

 

[MtnMan]

Current check will require an amp meter. One that encircles the wire.

Thank you! Does the fact that the voltage is ~14 Volts at the battery when the bike is running mean that the charging system works properly or is there a chance that the voltage is OK, but not enough current is generated?

Greetings from Colorado,
Armin

 

[slabghost]

Sounds to me like it's working properly now.

 

[WindNWing]

14.3 volts says that your charging system is working properly. If your starter is spinning the engin as it should, you have no worries.
The only reason to check the current in the starter system would be if your starter was draging or turning slow. Ride it.

 

[dan filipi]

Long story short, the way a regulator works is to regulate the voltage.
The alternator (stator) will produce what it needs, current wise to maintain a preset maximum voltage.
So lets say you shorted across the battery (dead short), the alternator would automatically produce to it's full capacity to maintain that voltage.

Your's is working perfect.

 

[Anonymous]

not taking anything away from what Dan and the guys are saying - your bike does appear to be working fine but if you wanted to check the current the way it shows in the picture you have to relocate the meter lead to the curent scale,

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• 1060dsl
• Nov 1, 2012

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To read voltage the black lead goes to the common (bottom spot) and the red lead goes to the center spot but current is read in series so the black wire stays on the bottom spot (common) and the red lead goes on the top. I have not tried it but the bike should start with the meter in this position (provided you did not blow the internal fuse on the Amp scale).

 

[MtnMan]

Thank you, guys, I appreciate your help, I am feeling more confident now. The bike starts very well and I also noticed that the headlight is brighter now.

I am just a little cautious after this....:

I will ride the bike and watch the battery voltage, temperature of wires etc.

Armin

 

[mcgovern61]

I will ride the bike and watch the battery voltage, temperature of wires etc.
Armin

Armin, you might want to try it while riding on the road. I'm not sure you will get the same results riding up there on the back of the truck! :smilie_happy: :smilie_happy: :mrgreen:

 

[Anonymous]

I will ride the bike and watch the battery voltage, temperature of wires etc.
Armin

Armin, you might want to try it while riding on the road. I'm not sure you will get the same results riding up there on the back of the truck! :smilie_happy: :smilie_happy: :mrgreen:

:smilie_happy: :smilie_happy:

 

[joedrum]

no storm damage on gerrys humour.... :smilie_happy: :smilie_happy: :mrgreen:

 

[MtnMan]

I will ride the bike and watch the battery voltage, temperature of wires etc.
Armin

Armin, you might want to try it while riding on the road. I'm not sure you will get the same results riding up there on the back of the truck! :smilie_happy: :smilie_happy: :mrgreen:

OK, OK...I will take her out on Sunday for some Rocky Mountain canyon carving! arty:

The ride on the tow truck was actually quite pleasant. The driver was a biker too and we had a great conversation.

Armin

 

[MtnMan]

You guys were right...everything works just fine. I just returned from 130 trouble-free test miles in the mountains. Engine starts and runs great, headlight is strong, couldn't be happier!

And it was mostly sunny, very mild, almost not traffic...late fall in Colorado.

Thanks again for your help!

Armin

 

[slabghost]

Always great to hear of a fix gone right. Congrats!