need advice on electrical draw. 69 camaro, 454, 4 spd, mostly stock wiring harness. No major electircal issues (everything works - plus I added a couple extra grounds here and there - just to have them)

Battery slowly drains when sitting.

- New battery. Alternator works fine, charges it right back up.
- Have you seen any trends in the 1st gen to lookout for?
- Easiest/cheapest way to isolate the problem?

Thank you kindly for any advice.

Frank

 

1) check for lamps in hidden places, such as the trunk or glove box, that remain on when the engine is turned off.
2) Pull each fuse one at the time till you find the one that stops the battery from running down. Then inspect the circuits protected by that fuse and find the components drawing current. May take a few days.
3) Same as #2, but insert an ammeter in series with the battery cables, either Pos or Neg (makes no difference) and watch meter as you pull fuses. The fuse that stops battery draw is your culprit.
-

 

thank you. might read main pos to ground for continutity, then pull fuses. but in the mean time, the battery self destructed today. shorted completely. when to fire it up after work - nada. not even lights - nothing on the voltmeter. new battery and it powered right up. might have been a defective battery?? battery only 6 weeks old? still going to read out system, see if it contributed in some way.

 

The battery probably died when you were testing the car. An open cell will prevent the battery from taking a charge and suffer a sudden death.

 

ok, dang. new battery was drained after sitting in car for two days while I was on travel. read pos cable (disconnected from battery) to ground. pulled all fuses, still showed continuity. finally discovered the alternator (which works - pushes 13-14 volts when running) was showing continutity/ground. **isolated it to the wire which senses load, heavy red going to harness** with it disconnected, the main charging wire and 12v switched wire do not read continuity. wish I knew what the wires should read on the alternator for continuity.

charging battery to play with it tomorrow - was hoping to drive this thing to nascar in pocono this weekend! might throw a spare battery in the trunk, but not into possibly playing with car after race! when it dies, it dies big!

 

Are you saying that the battery went dead with the cable disconnected from the + battery post? If it did, the battery is junk.

 

no sir, it died when everything was connected/normal.

- believe I found one of the better ways of troubleshooting by reading continuity. ""pos + battery terminal to ground with terminal disconected from battery."" this is fast and easy/even someone like me can do it

- certain things like my mallory hyfire, the alarm system and the radio
show coninutity - but nothing else should. (they all draw minimum load when sitting idle) I just disconnected them one at a time when pulling fuses/and or disconnecting wires.

- my alternator, seems to be the culprit. it showed strong continutity to ground. as i understand it, it should have nothing. when i disconnected the main sensing wire (heavy red wire to harness, not main charging wire) **that stopped continuity** so it seems my short was in the alternator.

- off to play with it this morning, now with a amp gauge (battery is now charged again) try to check amps out when not running.

- in other posts, people talked about grounds causing the battery to drain, I don't get it. a ground causes some crazy/wierd stuff when operating, but when sitting - can't see how it would do anything that would drain a battery. unless it's shorted to a pos wire.

 

My bet is the alternator. It was the issue with my other car. Battery would go dead in 8 hours. Changed the alternator and I've been fine for months now

 

Bad grounds will not cause battery to discharge, but may keep it from getting charged. A shorted alternator diode will allow reverse current flow and discharge the battery through the alternator.

 

Im with Pete. Let us know what you find Frankenstein