6V generator: Voltage too high (8,5V)!

B

bikemaniac

Senior Member
Hi,

This post is based on my previous post:

http://www.fordbarn.com/forum/showthread.php?t=192591

I bought a brand new 6V battery and everything seems fine: Plenty of power for the starter motor etc. But then I made some measurements and was shocked (measurements made from cut out relay to engine block stud with a digital Fluke multimeter):

Idle speed: 6,3V
Approx. "medium" speed: 7,3V
Approx. cruising speed: 8,5V

Charging rate is 10 Amps according to the car amp meter.

The 8,5V explains why it toasted my old battery while still having a normal charging rate.

What can I do to lower the voltage to 7,3V (according to Les Andrews)?

Lucas
 
The battery is the "regulator" for the generator. Put in a 6 volt battery and the voltage will be about 6 volts, put on an 8 volt battery and the same generator will put out about 8 volt and the same with a 12 volt battery.

The ammeter reading is high, what is the third brush set to? How are your grounds and other connections?
 
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It sounds like you have some unwanted resistance in one or more connections, including grounds.

10 amps is quite high unless you drive a lot at night.
 
The generator is a current device (amps) not a voltage device. Move the third brush in the generator to the CURRENT level you desire. A digital voltmeter will not be accurate with the noise on a Model A system. Use an analog meter, check voltage on the battery. then check voltage drop from the generator output to the battery and then the battery ground post to chassis ground. Voltage drop on both of those should be very low. If it is not low, find where the voltage drop is and repair it there. Post your readings and we can help you troubleshoot.
 
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Mike V. Florida said:
The battery is the "regulator" for the generator. Put in a 6 volt battery and the voltage will be about 6 volts, put on an 8 volt battery and the same generator will put out about 8 volt and the same with a 12 volt battery.

The ammeter reading is high, what is the third brush set to? How are your grounds and other connections?
Click to expand...

If there is 8.5V measured at the generator and 6V at the battery then there has to be some resistance between the two that eats up 2.5 volts.

:) Just my 2 cents. Have a nice day.
 
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That sentence in my post was referring to a post that was later deleted. It was one of the first posts and was very angry sounding. It was soon gone. Sorry for the confusion. I remember one of the firsts posts I ever did here on fordbarn, some guy read me the stupid act and I didn't post again for a long time. I'll go back and delete that line now as it is no longer relevant.
 
Ah, the light comes on again. Those pesky deleted posts can confuse us. I am going to go back and delete my post. Then go back and delete this post. Then post to explain what I did. Or maybe I will just go outside and lean against a post for awhile.
 
eagle said:
That sentence in my post was referring to a post that was later deleted. It was one of the first posts and was very angry sounding. It was soon gone. Sorry for the confusion. I remember one of the firsts posts I ever did here on fordbarn, some guy read me the stupid act and I didn't post again for a long time. I'll go back and delete that line now as it is no longer relevant.
Click to expand...

Cool Hand Lurker said:
Ah, the light comes on again. Those pesky deleted posts can confuse us. I am going to go back and delete my post. Then go back and delete this post. Then post to explain what I did. Or maybe I will just go outside and lean against a post for awhile.
Click to expand...


Understood!

Bikemaniac, I'm sorry your request for information got side tracked.

Have you tried the suggestions about the grounds?
Let's see if we can get you back on track and get your problem solved.
 
I havent had time for testing yet, but will begin tomorrow. Another question:

When the headlights are turned on ... and I switch them off, is it normal that the current drops slowly according to the amp meter ... or should the current drop abruptly? In my car the current drops slowly. However when I turn the headlights ON, the current increases abruptly.

Lucas
 
bikemaniac said:
I havent had time for testing yet, but will begin tomorrow. Another question:

When the headlights are turned on ... and I switch them off, is it normal that the current drops slowly according to the amp meter ... or should the current drop abruptly? In my car the current drops slowly. However when I turn the headlights ON, the current increases abruptly.

Lucas
Click to expand...

What kind of bulbs do you have? Incandescent should give a rapid movement of meter.
 
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