My 1972 Pantera Has a New Battery. 2 months old. Car is not charging it. how do I check the Alternator or Voltage Reg.? Had to get a jump to get it Home.
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do you have the original charging system?
do you have a voltmeter with at least 0.1 VDC resolution?
I would get battery voltages with
1)disconnected
2)connected, but off
3)running at idle and then 2K rpm intervals without any load
4) idle and 2K intervals with as much load as you can (fans, high beams, brake)
1 and 2 should be the same
1 and 3 idle should have an increase (can't recall how much)
3/4 above idle should be greater
if voltage drops below 1 while 3/4 then absolutely no charging is happening
You can bypass the regulator and go full charge demand on the alternator to see if it is one or the other
do you have a voltmeter with at least 0.1 VDC resolution?
I would get battery voltages with
1)disconnected
2)connected, but off
3)running at idle and then 2K rpm intervals without any load
4) idle and 2K intervals with as much load as you can (fans, high beams, brake)
1 and 2 should be the same
1 and 3 idle should have an increase (can't recall how much)
3/4 above idle should be greater
if voltage drops below 1 while 3/4 then absolutely no charging is happening
You can bypass the regulator and go full charge demand on the alternator to see if it is one or the other
With the engine running have some one bring the revs over 1000rpm and then remove the positive battery terminal. If the car dies then the alternator/reg are not working. That's the quickest way.
Trying to run the car without a battery is an old school test (go / no go). If you have any electronics like stereo , ignition box or what ever it may get damaged. A newer car with efi would be disaster!
Get the battery charged at a auto service center and load tested. You need to know the battery is still good. Get a digital volt meter , a hobby quality will work. ($10~)
Disconnected about 12 volt.
Connected but ignition off the same result. anything less you have a draw from a wiring error or fault.
Engine at idle minimum loads 13 volt , rev engine no higher than 14.7
Turn on all the loads is a test of alternator capacity . You will get less voltage than previous test with a stock charging system.
A charged battery but no charging system is not going to get you real far even with minimum loads. My guess 20-30 mile on a expressway.
My solution a expanded scale volt meter in place of the amp meter. A ford gen 3 alternator from PA Performance (95 amp) fits with out modification , a larger wire from alternator to the starter solenoid and a circuit breaker/ fuse (150 amp).
https://www.paperformance.com/...iew.asp?idproduct=46
Why would anyone install a Delco? They have a magic box to keep the idiot light working also.
The only problem was a cogged v belt slips at start up, a solid one works.
Get the battery charged at a auto service center and load tested. You need to know the battery is still good. Get a digital volt meter , a hobby quality will work. ($10~)
Disconnected about 12 volt.
Connected but ignition off the same result. anything less you have a draw from a wiring error or fault.
Engine at idle minimum loads 13 volt , rev engine no higher than 14.7
Turn on all the loads is a test of alternator capacity . You will get less voltage than previous test with a stock charging system.
A charged battery but no charging system is not going to get you real far even with minimum loads. My guess 20-30 mile on a expressway.
My solution a expanded scale volt meter in place of the amp meter. A ford gen 3 alternator from PA Performance (95 amp) fits with out modification , a larger wire from alternator to the starter solenoid and a circuit breaker/ fuse (150 amp).
https://www.paperformance.com/...iew.asp?idproduct=46
Why would anyone install a Delco? They have a magic box to keep the idiot light working also.
The only problem was a cogged v belt slips at start up, a solid one works.
I got one of these little digital voltmeters: eBay item number:
111411914237
Plugs into the cigarette lighter. $2.50 delivered. I don't know how they do it.
111411914237
Plugs into the cigarette lighter. $2.50 delivered. I don't know how they do it.
Very, very simple. You do need a multimeter though.
Find the cars battery. Identify the terminals.
Start the car. Let it idle.
Set the multimeter on the 15v dc setting.
Touch one lead to the red terminal= plus, the black lead to the - terminal.
The reading should be 13.3 to 13.8v. If it is, alternator is good.
If it is 12.5 or less, alternator is not working and the car is running on the battery.
If it is 15.8v, the battery is run down and is charging. Let the car run 10 minutes. Voltage should drop to 13.8 while running. If it does, regulator is good too.
Shut the car off. Read the battery again. If it is 12.5, battery is full charged.
Let it sit for a hour or so. Read the battery again. Should be at least 12.2.
If you are at 11.8 or lower, battery is on the way out. Replace it asap.
Find the cars battery. Identify the terminals.
Start the car. Let it idle.
Set the multimeter on the 15v dc setting.
Touch one lead to the red terminal= plus, the black lead to the - terminal.
The reading should be 13.3 to 13.8v. If it is, alternator is good.
If it is 12.5 or less, alternator is not working and the car is running on the battery.
If it is 15.8v, the battery is run down and is charging. Let the car run 10 minutes. Voltage should drop to 13.8 while running. If it does, regulator is good too.
Shut the car off. Read the battery again. If it is 12.5, battery is full charged.
Let it sit for a hour or so. Read the battery again. Should be at least 12.2.
If you are at 11.8 or lower, battery is on the way out. Replace it asap.
Do what Doug said.