1965 - Dead Battery

[Mike Malouin]

I have a 1965 big block. Car runs great for about 15 minutes then the battery starts to drain to the point that the car will not restart w/out a jump. At first I put in a new carburetor because the car was dying when idling at a stop light. Turned out to be a coincidence. After a period of time, it started happening while I was in gear and driving. I have put in a new battery - same problem. Then I replaced the alternator - no difference and then the voltage regulator. Same thing happens. Any suggestions as to where to look next?

[Kevin Whiteley]

Re: 1965 - Dead Battery

Mike, I can't tell from your post if you suspect that the the car dying while in gear is a result of your bad carburetor or from your battery problem. If the car dying while in gear is a result of a bad carburetor, then your "battery" problem may be the starter.

I used to have a 73 Super Duty 455 Trans Am which used to do the same thing. After driving the car, either for a short or long time, the car would be impossible to start. I was later able to determine that battery, even though drained, wasn't the culprit. It was the starter. To elaborate, the engine, or more specifically, the headers, were putting out so much heat that the starter would get hot. Then the battery wouldn't have enough amps to turn the starter over, until I either waited long enough for the starter to cool down, or get a jump. The jump would add enough amps for the starter to turn over. My temporary fix was to add a "heat shield".

[William C.]

Re: 1965 - Dead Battery

What charge level are you seeing on your ammeter? Is the regulator properly grounded?

[William V.]

Re: 1965 - Dead Battery

Check the charging voltage at fast idle (around 1500 rpm) should be 14.2 to 15 volts. A fully charged battery reads around 13.2 volts.

[Eugene B.]

Re: 1965 - Dead Battery

There would have to be a tremendous current drain for something to run a fully charged battery down in 15 minutes. None that I can think of, especially since you have replaced the starter, etc.

I wonder if the problem could be the ignition coil? They tend to fail when they get hot. A check might be to get out and feel the coil when the motor dies. If the coil is very hot to the touch, it may be defective. Substituting another coil would be a cheap thing to try.

Good luck,
Gene

[Kevin #38315]

Re: 1965 - Dead Battery

Mike,

You need to stop replacing things and start testing more.

First, I'm not clear on something... Does the car still stall after running 15 minutes, or was this fixed by changing the carburator?

Can you be more specific with the symptoms? Once you restart the car with a "jump", how long will it run? Does it make a difference if you turn the headlights on? Are the headlights bright or dim when you turn them on (when the engine is running)

Will the battery go dead if you just let the car sit and idle for 15 minutes, or only if you are driving it?

Kevin

Kevin