Battery drain(s)?

[Voodoo81]

Left my car in the garage for 4 days while I was out of town. Have a brand new alternator (last week) and battery (3 weeks ago). There are no obvious power drains (headlights on, radio, dome light, etc). Got in to fire it up today to see if my new electric choke and newly-rebuilt carburetor would fire it up like I hoped and found .... a dead battery (again).

Are there any common electrical drains in an '81?

Don't really even know where to begin - take it to an auto store and have them test it overnight was the first thing that came to mind. Cry myself to sleep until I solve the problem was option b.

Any thoughts?

Thanks
John

 

[topless82vette]

I had a problem like this on my old 1993 mustang gt. I used this approach to locate the drain in the car which turned out to be the cars amplifier.

disconnect your positive battery cable and connect a hand held voltage guage between the cable and the battery post. It's been sometime since I did this but this is the general idea on how to do it.

Anways after you hookup the voltage gauge pull fuses this you see the drain dissapear from the gauge. If it doesnt then unhook the alternator wires and see if it is draining there. It's pretty easy to find which circuit the drain is coming from like this.

 

[baxsom]

i always just put a light on a long wire between the neg cable and the post.

if the light came on you have a drain.

then you can work under the dash, hood etc and if the wire is long enough have the light always in sight to see when it goes out.

 

[Mr. Chuck]

Some other visual check points before you start pulling things apart are: Hint: perform these at night or in a darken garage; 1. The Spare tire light (visable on garage floor), 2. The glove compartment light (if door latch adjustment is off, light will stay on). 3. Cigar lighter is in pop-out position, doesn't show sign of over heating, especially if you don't smoke. 4. Under hood light (I put in a seperate switch, so I can turn light off if hood is open for extend periods of repair time).
Once you have test light connected between battery and negative cable; I would check the alternator wiring since it was recently worked on especially if they also worked on or replaced the wiring going to the alternator.
Hint: Allso, look at any other service done recently first, I even had an experience when I gunked the engine and ended up with a short in the fire wall connector located on the driver side, behind the brake vac boost / master cylinder caused some circuit malfunctions.

 

[6880 Mike]

Got a lighted vanity mirror on the passenger's sunvisor? Check to see if it's on. Sounds silly, but that was the culprit for the slow drain on my fiancee's '96 convertible.

 

[LVMYVT76]

My 76 has a map light under the rear view , gets turned on by the gremlins.