alt not charging, driving me nuts

[notlowenf]

Ok new alt.and tested at napa.that its good. New fusable link and new voltage reg. I dont have a bulkhead looks like everything was cut and soldered together. i looked at all the wires and didny notice any burned out. also made new ground from the engine to firewall. Gotta be something simple im overlooking any suggestions would be appreciated. 68 fury 3

 

[1978 NYB]

Check the battery. How old is it? You can take the battery to AAP or AZ and they can check it to see if there is a dead cell and/or if it'll take a charge. Also check the ground going to the engine block/frame so it has a solid connection and not corroded or loose.

 

[rexus31]

Make sure you have continuity on the Field wire form the voltage regulator and the alternator. I had the same issue and determined a bad crimp on one of the connectors on the Field line (new harness)

 

[notlowenf]

New battery also. The reg has two fields. Think im going to change out the harness it does feel loose. Do you know what they should read with a voltmeter?

 

[Big_John]

Wait... Do you have a single field system or has the car been converted to a dual field? If you have two field connections on your new alternator and a single field regulator, the extra field connection on the alternator will need to be grounded.

And charging voltage should be about 14 volts.

 

[notlowenf]

On the alt there is a fusable link with a nut and than one plug in field. Does that mean i have a two field? And the reg has two fields. I did ground the alt as well.

 

[Big_John]

That's a single field alternator. By two fields on your regulator, do you mean two connections? One should be a field connection and the other connects to your ignition switch.

You really need to check voltage at the battery. It should be 12v with the car not running and 13.5 to 14.5 with the car running and no lights or accessories on. Don't base any decisions on the ammeter in the dash.

 

[Dale Michaels]

I would check the voltage going into the reg,it should be 12 going in and out,I recently had the same issue,I bought a new reg and later found it to be bad,the parts store suckerd me into a new alt but I refused to buy a new battery,I went home and broke out the meter and found the volt reg wasen't sending any power to the alt to get it to charge,,,

 

[notlowenf]

Single field alt and volt reg. I'm only getting 8.5 volts off the reg on each side of it. Getting 12 volts off the alt stud and the battery itself. The reg seems to be grounded well its not loose. And when I turn the car on the voltage goes no where stays at 12.

 

[Big_John]

OK. Now we're getting somewhere.

Here's how to check the voltage regulator. Unplug the field connection and run a jumper wire from the battery connection to the field connection on the alternator. Start the engine and check the voltage at the battery. If it's 14 or more volts, then you can figure it's the regulator. Don't run the engine like this for long though.

 

[notlowenf]

Bypassed the ammeter on the back of the instrument panel and were charging again!!! Thanks everybody, very appreciated.

 

[commando1]

I love this place....

< Sent from my tablet >

 

[luistito]

How do u test a two field alternator and voltage regulator?