1974 "Battery" gauge
Thread Starter
Drifting
Joined: May 2005
Posts: 1,909
Likes: 6
From: Lake Arrowhead - Georgia > 72 Base Coupe & 74 BB Roadster
1974 "Battery" gauge
My 74 has a "BATTERY" gauge. It reads from -40 to 0 to 40+.
What is this gauge telling me.....the current amps from the alternator ...or...the current draw on the battery????
I am starting to think that my alternator is going out, because the "battery" gauge constantly goes from zero to +40 as the engine revs up. It moves from zero to +40 in "concert" with the tachometer.
Help! 
What is this gauge telling me.....the current amps from the alternator ...or...the current draw on the battery????
I am starting to think that my alternator is going out, because the "battery" gauge constantly goes from zero to +40 as the engine revs up. It moves from zero to +40 in "concert" with the tachometer.
Help!
Racer
Joined: Mar 2006
Posts: 366
Likes: 1
From: Houston Texas
Agree with Glass - the function, whether an ammeter or voltmeter, is to tell you if the battery is charging (+) or discharging (-). A strong battery will get to 0 if you drive long enough as it becomes fully charged.
In the winter when its raining, my 76 will actually go (-) at a stop light as I have the headlights, heater blower motor, radio and wipers all running, and only 600 rpm turning on the alternator. It will go (+) when I start moving again and settle at 0 once the momentary discharge is replaced.
In the winter when its raining, my 76 will actually go (-) at a stop light as I have the headlights, heater blower motor, radio and wipers all running, and only 600 rpm turning on the alternator. It will go (+) when I start moving again and settle at 0 once the momentary discharge is replaced.
Drifting
Joined: May 2008
Posts: 1,505
Likes: 7
From: Jacksonville FL
Same as in my 80. I stop in gear at night with my lights on.. usually in McDonalds drive thru the amazing symphony my sidepipes make off the brick wall.... better then a McChicken any day.... anyways... yeah usually then it drops to around 0.. but usually a little over. Now driving its usually up... not all the way but high enough.
Keeping that in mind when I idle at McD's or wherever I usually drop it in gear with everything in for a minute or so then I'll turn the lights off and let it idle in neutral so I dont drain my battery. Revving it up is also nice
Keeping that in mind when I idle at McD's or wherever I usually drop it in gear with everything in for a minute or so then I'll turn the lights off and let it idle in neutral so I dont drain my battery. Revving it up is also nice
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
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Burning Brakes
Joined: Nov 2001
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Fred - my experience with batteries is this: You usually get a hint, and then they die. If you are getting a hint, act quickly before you get stranded with a dead battery.
If this is your hint, and/or if it's been about 5 years, get a new battery. Even if yours tests out fine.
If this is your hint, and/or if it's been about 5 years, get a new battery. Even if yours tests out fine.
Drifting
Joined: May 2008
Posts: 1,505
Likes: 7
From: Jacksonville FL
Even a little hint as I dunno a light from an accessory flashing or powering on and off. Or sometimes slow to lug over. In my car the battery gauge doesnt show me how dead the battery is just how much charge its getting. That being said I have to keep an eye out for hints to when my battery is low. Hopefully it wont hint anything for a few more years.
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Le Mans Master
Joined: Jan 2000
Posts: 8,918
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From: New Hill NC
My 74 has a "BATTERY" gauge. It reads from -40 to 0 to 40+.
What is this gauge telling me.....the current amps from the alternator ...or...the current draw on the battery????
I am starting to think that my alternator is going out, because the "battery" gauge constantly goes from zero to +40 as the engine revs up. It moves from zero to +40 in "concert" with the tachometer.
Help!
What is this gauge telling me.....the current amps from the alternator ...or...the current draw on the battery????
I am starting to think that my alternator is going out, because the "battery" gauge constantly goes from zero to +40 as the engine revs up. It moves from zero to +40 in "concert" with the tachometer.
Help! Those of you that have a volt meter, it only tells you that the alternator is charging, and what the voltage is. This does not give you much indication of battery condition, just the condition of charging system. Those with an ammeter can tell a little more about battery condition. A new battery will charge very hard and deep for a longer time to recharge after a discharge. You learn what that charging time and rate is. As the battery ages and its ability to store a charge diminishes, that charge rate and time will get less and less, until the point when you start the car, and there is very little indication of recharge. You will know that the battery is on its last leg. The reserve will be low and the ability to recharge will be low.
