A friend of mine has a 67 Camaro, 327 with AT.
His battery has died and I suspect a short somewhere because in just one night, a fresh battery is so dead that the car has nothing. Not one noise from the starter, no lights that battery is completely dead.

I want to jump start him and make sure the alternator will charge. How do I confirm that the alt is charging?

Measure across the battery terminals the charge voltage. Otherwise, measure from BAT terminal on alt to ground.

If voltage at alt, then limited to wiring problems. Check buss bar at horn relay for good connection.

Later, after battery has been externally charged by battery charger, put test light between battery cable and battery post to see if a circuit is drawing current. Pull fuses and wires to find faulty circuit. Troubleshoot from last circuit.

A poor mans alternator test is to charge the battery fully then start the car and remove the positive cable. If the car stays running..its charging. If it dies, its not ! Do not leave the cable off too long if it stays running.

Kev

A poor mans alternator test is to charge the battery fully then start the car and remove the positive cable. If the car stays running..its charging. If it dies, its not ! Do not leave the cable off too long if it stays running.

Kev

Why is it bad to leave the cable off?

Measure across the battery terminals the charge voltage. Otherwise, measure from BAT terminal on alt to ground.

If voltage at alt, then limited to wiring problems. Check buss bar at horn relay for good connection.

Later, after battery has been externally charged by battery charger, put test light between battery cable and battery post to see if a circuit is drawing current. Pull fuses and wires to find faulty circuit. Troubleshoot from last circuit.

So measuring from alt to ground while its running should show me 12+ volts? If not the alt is bad.

Where is the voltage regulator?

Would putting a ohm meter between the disconnected positive terminal and ground show me an open if all was good? And if not would there be an resistance or a short?

Measuring from the alt to ground with engine running should be closer to 14V. Rev engine and see if it climbs. I had a burnt wire under dash stopping my alt from charging until I reach about 3500rpm's. Once excited it stayed charging.
Measuring from the disconnected pos battery cable to gnd will read whatever resistance is in the circuit. It should not be a short. Do like Everett#2390 said and pull pos cable off, if your meter reads (ma) milliamps, connect one lead to pos battery post and other to pos cable. Your basically inline with battery. Make sure you have the test leads in the proper insert for reading milliamps. It not the same as reading volts or ohms. If you have a test light, it's even easier. If he has an aftermarket radio or clock you will see some battery drawer but it should be very minimal. Not enough to drain a battery overnight.
I would just pull alt and take down to AutoZone and have them check it out for free. That way they can put a load on it. Don't forget to check connections on volt regulator. Not exactly sure where it is on 67, but on 69 it's located on radiator support (driver side).

Thank you.....

We're going to his storage unit with a bag O tooles and my meter. Hopefully we can get this baby running.

Then we'll have to troubleshoot why he gets almost no vacuum at idle. But that's a post for a different category.

Measuring from the alt to ground with engine running should be closer to 14V. Rev engine and see if it climbs. I had a burnt wire under dash stopping my alt from charging until I reach about 3500rpm's. Once excited it stayed charging.

Switched power goes through the bulb to the regulator to start the charging, extenal regulators will not excite that I remember. We used 13.8V to 14.8V as acceptable, any less =not charging. Has to carry load of lights and heater also but not necessarily at idle.

{/quote}Measuring from the disconnected pos battery cable to gnd will read whatever resistance is in the circuit. It should not be a short. Do like Everett#2390 said and pull pos cable off, if your meter reads (ma) milliamps, connect one lead to pos battery post and other to pos cable. Your basically inline with battery. Make sure you have the test leads in the proper insert for reading milliamps. It not the same as reading volts or ohms. If you have a test light, it's even easier. If he has an aftermarket radio or clock you will see some battery drawer but it should be very minimal. Not enough to drain a battery overnight.{/auote}

I read this three times before I realized he meant with the engine OFF.
(thinking my meter probably won't carry that much current through it with engine running)
I would just pull alt and take down to AutoZone and have them check it out for free. That way they can put a load on it. Don't forget to check connections on volt regulator. Not exactly sure where it is on 67, but on 69 it's located on radiator support (driver side).[/quote]

Bench test alt if they're close first to eliminate that variable

Good luck!

Jeff.

{/quote}Measuring from the disconnected pos battery cable to gnd will read whatever resistance is in the circuit. It should not be a short. Do like Everett#2390 said and pull pos cable off, if your meter reads (ma) milliamps, connect one lead to pos battery post and other to pos cable. Your basically inline with battery. Make sure you have the test leads in the proper insert for reading milliamps. It not the same as reading volts or ohms. If you have a test light, it's even easier. If he has an aftermarket radio or clock you will see some battery drawer but it should be very minimal. Not enough to drain a battery overnight.{/auote}

I read this three times before I realized he meant with the engine OFF.
(thinking my meter probably won't carry that much current through it with engine running)

Yes your correct . With engine off. I guess I should have mentioned that. With engine running you probably wouldn't have a meter very long or test leads.