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1966 Ply Satellite Alternator

Posted By: BAM

1966 Ply Satellite Alternator - 10/14/09 10:37 PM

Hi All,

Replaced a dead alternator (Auto Shop tested it) in my 66 Plymouth, but unclear of what i see for voltage at the battery (the battery is brand new and charged to 12.5). I am used to newer cars where you see a decent charging voltage (13.5), here I see 12.2 at idle and the in-dash ammeter shows little change, but the voltage does go up when I rev the engine (12,3, 12.4)and the ammeter moves to the charging side, is this normal?

Thanks, BAM
Posted By: GTX MATT

Re: 1966 Ply Satellite Alternator - 10/14/09 11:03 PM

If its not on the discharge side at idle then you're lucky, alot of them discharge. Remember the ignition system doesn't run on 12 volts either, it only uses 12 when its starting.
Posted By: BAM

Re: 1966 Ply Satellite Alternator - 10/14/09 11:15 PM

so what I am seeing is normal????

Thanks, BAM
Posted By: Andrewh

Re: 1966 Ply Satellite Alternator - 10/15/09 12:31 AM

no I don't think so. At idle maybe. But when you rev you should still get that 13.5 or around 13.

Start checking for at the alt and see if you are having a voltage drop.

Or the vr and see what the sensing voltate is.
Posted By: BAM

Re: 1966 Ply Satellite Alternator - 10/15/09 01:00 AM

thanks, there is a wire connected to a "screw post" on the unit, and a wire that slips on to a flat blade on the alternator, what should the voltage be at each point when measured to ground?

Tks, BAM
Posted By: ahy

Re: 1966 Ply Satellite Alternator - 10/15/09 01:43 AM

Quote:

Hi All,

Replaced a dead alternator (Auto Shop tested it) in my 66 Plymouth, but unclear of what i see for voltage at the battery (the battery is brand new and charged to 12.5). I am used to newer cars where you see a decent charging voltage (13.5), here I see 12.2 at idle and the in-dash ammeter shows little change, but the voltage does go up when I rev the engine (12,3, 12.4)and the ammeter moves to the charging side, is this normal?

Thanks, BAM




If the ammeter goes to charge and the battery voltage is only 12.3 or 12.4 either the battery is down somewhat or the voltmeter is off. Just starting the car would draw the battery down enough to keep the voltage low for several minutes. Its possible all is well and you need to run it down the road for 20 minutes to bring the battery up than test again. The MOPAR regulator, when warm, should put out around 13-13.2 volts with the at engine at fast idle or more, a charged battery and no heavy electrical loads.
Posted By: dave571

Re: 1966 Ply Satellite Alternator - 10/15/09 03:41 AM

Quote:

thanks, there is a wire connected to a "screw post" on the unit, and a wire that slips on to a flat blade on the alternator, what should the voltage be at each point when measured to ground?

Tks, BAM




The big post should be close to battery voltage.
The spade connector will vary with the charge rate.

ALL you need to know is that the charge system voltage should be between 13.5 and 14.5 at the battery.
With the accesories off, it should be that much at idle too.

If it's not, then the alternator is not giving enough output. Either because the regulator isn't telling it too, or ther is a problem with the alt, or the wiring etc..

It sounds to me like the regulator is bad. Very common to have a reg go bad at the same time as the alt. In the old days, lot's of guys changed them at the same time automatically.
Posted By: therocks

Re: 1966 Ply Satellite Alternator - 10/15/09 03:34 PM

Especially if its the old points type reg.If it is get a new one thats electronic.They are around 20 bucks and hook up just like the OE points style.Rocky
Posted By: BAM

Re: 1966 Ply Satellite Alternator - 10/17/09 05:54 PM

Thanks All for the replies......

Turns out the car just had to warm up after a short drive and the charging voltage went to normal!

BAM
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