1975 new battery, car keeps losing charge

[Woodrow]

Greetings all, I'm posting for the son of a close friend, he just got a '75 as his first car. PO took good care and put a new battery in before selling--apparently it went dead sitting in his driveway. Now, this kid goes to stsrt it and the battery is desd again. They say they had checked the hesdlights and hadn't left them on. I'm in a different state right now, just trying to help them out--single mon, son's new car. Any ideas what could be draining the battery?

Hope that's not too vague. I'm going on the info I have thus far, but will try to get more as needed. Thanks, and glad to be a member.

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[RichLo1]

Slow battery drain when parked is pretty common. Check for anything aftermarket installed or removed. Look for bare wires going through a hole drilled in the firewall, this is the most common types of phantom drains. Without a multimeter this is the most you can really do besides unhook the battery every time its going to sit more than a couple days. With a multimeter you can read amp draw with the key off and pull fuses one at a time until the amp draw goes to 0.

 

[Docj]

Here's a suggestion if he doesn't have a multieter and/or doesn't know how to use one. There should be an external voltage regulator mounted on the cowl. It's a cheap enough part to try. Just throw one in and jump it (or put on a rapid charge on the battery while switching it out). They're really easy to dismount/mount, as well. If he's going to be driving a vintage car, he needs to get comfortable with doing the repairs! The contacts could oxidize shut over time with disuse.

 

[Woodrow]

Good looking out! I'm trying to teach him a few things long distance and over video chat. They're al pretty willing to pick up new skills.His mom just learned how to pour a little gas in the carb to start it after tank got too low! I got him the Ford 75-76 shop manual and will send him a multimeter with a few other tools I'm putting together. This site has proven to be an excellent resource. Thanks all!

 

[RichLo1]

Make sure he knows how to properly use the multimeter in Amp mode otherwise He'll blow the 20a fuse in there and not even know it. and it'll just read 0amps until he replaces that fuse.

 

[Thunder rd]

The most common draw down with fords is the brake light switch on the brake pedal. The other is a diode in the alternator . A meter will tell the draw so will a tester light. If you can't find any thing on undo the alternator to batt. Check draw. .