voltage?

[chopperBob]

hey guys just got my cobra on the road today for a quick run to the store.
turned it off and went inside 5 minutes. when i got back the battery wouldent start the car. well finally got her to jump got it home and put the voltmeter on the battery it was at high 10s low 11s nothing more even when i gave it gas . what do you think battery or regulator ? i did check the wiring its good .
thanks Bob
p.s. i did a search couldent find what i was looking for .

[wizard]

Could be either Voltage regulator or alternator. The regulator tells the alternator how much. My suspicion is the alternator because you don't get a changing voltage with RPM. Best to get it checked by by someone with the know-how. Any GOOD repair shop should be able to and some Auto Stores like O'Reilly's and AUTOZone have the diagnostic equipment and test for free.

[chopperBob]

well i took the alternator in for testing it tested good so its probly the regulator
if the regulator doesent excite the alternator will it turn on?

[any4xx]

Originally Posted by chopperBob

well i took the alternator in for testing it tested good so its probly the regulator
if the regulator doesent excite the alternator will it turn on?

I don't think so. The good news is that a regulator should be about $15.00.

[trularin]

Make sure the regulator is grounded, but more over, do a search on this.

There are at least ten good threads with how to determine what is wrong and how to find out what to do.

[Excaliber]

The regulator itself needs to be 'excited', usually with a 12 volt source that often goes through your 'Ignition' light. If the light itself doesn't work it could be as simple as a burned out bulb. THAT would not allow the 12 volts to turn on the regulator.

Using a volt meter you can check the regulator terminal to see if it has 12 volts when the key is ON. I THINK the terminal is marked "I" for ignition.

[Unique 289_FIA]

Originally Posted by Excaliber

The regulator itself needs to be 'excited', usually with a 12 volt source that often goes through your 'Ignition' light. If the light itself doesn't work it could be as simple as a burned out bulb. THAT would not allow the 12 volts to turn on the regulator.

Using a volt meter you can check the regulator terminal to see if it has 12 volts when the key is ON. I THINK the terminal is marked "I" for ignition.

Ditto this. I just recently went through replacing the battery, alternator, and regulator only to discover that the whole problem was caused by a loose connection at the warning light.

[chopperBob]

so it must be a switched power not constant ?
the previos owner had it wired as a constant 12 volts so it was on all the time rite? could be why the regulator went bad?

[trularin]

It is switched. usually comes off the primary ACC or IGN side of the electrical.

If you want, there is a 1965 T'bird wiring diagram in my photos that shows an alternator connected with indications of what goes where. This should be enough to help re-establish a charging system.

Hope this helps.