CaliforniaMustang 10 Report post Posted February 28, 2009 I bought a cheap-o autolite battery to replace my Optima Red Top that was needing a charge after every drive. Two weeks later this new battery is also needing a charge, so I'm trying to figure out where to begin tracking down the voltage leak. I have a multimeter, but am pretty new to diagnosing circuits etc. I drive the car about once a month, and I have replaced the battery cables, engine ground strap, voltage regulator, starter solenoid, and switched to a 1-wire alternator. I assume I hooked everything up correctly (the car runs LOL), but maybe I miswired the alternator or something... Could some random wire behind the dash cause the drain, or am I looking at the major ignition components? Quote Share this post Link to post Share on other sites
S code 69 13 Report post Posted February 28, 2009 Lots of things it could be, I'd take a battery cable off and touch it to the post with everything turned off, see how much of a spark you get and that will give you an idea how bad your short is. then by proccess of elimination start unpluging one thing at a time until you don't get a spark. most of the time you can figure it out this way if it's bad at all. Check out the alternator and voltage regulator this way too, I've had both cause problems. Quote Share this post Link to post Share on other sites
69in2006 11 Report post Posted February 28, 2009 You could diconnect the negative battery cable and put a test light in between the two..If the test light is illuminated then you have a draw..start unplugging or pulling fuses until the light goes out..dont forget to unplug the door switches if you have the door open when removing fuses... Quote Share this post Link to post Share on other sites
Fordrevhead 29 Report post Posted March 1, 2009 since you also changed the alternator I would suspect that first. With the car running check the voltage across the battery posts with your meter, red on pos, blk on neg. Should be in the neighborhood of 13.5-14.5. If it isn't then that's your problem. Go re-read the one wire instructions. If the alternator is not charging then you're driving on the battery then leaving it uncharged until next time you drive it. Hard on a battery and if it gets real cold a dead battery can freeze and be ruined. Quote Share this post Link to post Share on other sites
EastYorkStang 63 Report post Posted March 2, 2009 Put an meter between the battery and the removed pos cable. Check how many amps you're getting. Do you have a radio that is not switched? Quote Share this post Link to post Share on other sites
ForceFed70 14 Report post Posted March 3, 2009 Put an meter between the battery and the removed pos cable. Check how many amps you're getting. This is the best way. Put an ammeter in there and measure actual current draw. Then start pulling fuses or disconnecting components until the current draw drops off. Quote Share this post Link to post Share on other sites
