Battery Draining

[JohnnyJ]

I've been trying to find a short that drains the battery on my "79", but still getting no where.

I hooked up an AMP meter to the hot lead and the battery and get a reading of .085 regardless of which fuse I pull.

Does anyond have a system I can use to follow to get to the short??

I REALLY need help.

Thanks JohnnyJ

 

[Space Cowboy]

I feel your pain JohnnyJ... I went through the same thing. Below is a message that Rare81 sent me during my problem. In addition to his comments, check the wiper service switch if you haven't already. Mine propblem ended up being a user error This is my first Vette and I never knew that you were able to take the key out of the ignition while still in the accessory position. I still had a 7v drain somewhere, but it wasn't draining my battery too much at all. I'm in the middle of a near complete restore and my baby is getting new wires throughout.

Good Luck

'There are circuits that will have voltage with the key off e.g. "Clock and Cigarette Lighter" come to mind, the Radio may or may not depending upon model and electronics of the Radio.

As a note to possible help you with understanding a bit more about this type of testing.. the purpose of pulling the fuse then testing from one side of the fuse clip to grd.. if it is a "Hot" circuit you should read voltage from the fuse clip to ground, if it is a Ignition Key controlled Hot Leg then the key will need to be in the on/run or acc. mode to read voltage to grd. Ideally you would read voltage (11+ 2 volts) from the battery side of the fuse clip and 0 volts from the load side of the fuse clip with the fuse pulled."

I wish you luck in chasing these gremlins down, sometimes they seem to be magic. I've found bulb sockets to be a source of drain, they get old and corrode and form a path to grd and slowly drain the battery. Other places I've found grounds are from the vanity mirror switch, door switch to the hood light wiring.

It also will help if you WRITE DOWN the tests you conduct and voltage and notes. At some point you may find yourself going in circles without documenting your progress."

 

[bobherr46]

I just went through the same ordeal with my 79. Pulled every fuse,disconnected the alternator and even put a new regulator in the alt. No luck!!! Just gave up and put a disconnect on the battery negative terminal. Why fight it? - Bob

 

[80redbeast]

I just went through the same ordeal with my 79. Pulled every fuse,disconnected the alternator and even put a new regulator in the alt. No luck!!! Just gave up and put a disconnect on the battery negative terminal. Why fight it? - Bob

Exactly what I did. Too many electrical gremlins on these cars. You'll spend years trying to track half of them dowm, and the other half just go away by themselves and are replaced by new ones.

 

[Paul T]

I've been trying to find a short that drains the battery on my "79", but still getting no where.

I hooked up an AMP meter to the hot lead and the battery and get a reading of .085 regardless of which fuse I pull.

Does anyond have a system I can use to follow to get to the short??

I REALLY need help.

Thanks JohnnyJ

I had the same problem on my 79 and I suggest you get the Chevrolet shop manual which has very good wiring diagrams in it. I chased through every circuit and finally isolated it to the buzzer warning unit. As I recall, this part cost about $25.00 and is very easy to replace. Everything plugs in. Good luck.
Paul

 

[81LT4]

where can I find a shop manual that show the wiring diagrams
I am having this same problem, except my blower motor comes on
when I turn the key off, and i have a very very slight hum in my alt.

 

[Paul T]

Most of the Corvette supply houses (Mid-America, Ecklers, Corvette Central, etc) sell manuals for Corvettes of all years. Good Luck.Paul

 

[steves1980]

yeah i found out i have mine draining to, ? if you have a bad connection, would it drain the battery?, what i have is someone changed it over to a up post, put junk connections on, i replaced the neg. side and worked on the pos. side, what it is , is a cable with a alum. or lead fitting that is way smaller then the cable, so the nut cut half the wire off to fit, i drilled it out to take most of the wire, started fine, but has been sitting for a few weeks, wanted to drive it today, and was dead , mess with the connections,and i did get a dome light but real dim, iam chargeing it now, going it go out and work on it now, i realy dont want to replace that long cable, alot of work, but ? is would it drain it if it had a bad connection? ty

 

[mbwalker]

I've been trying to find a short that drains the battery on my "79", but still getting no where.

I hooked up an AMP meter to the hot lead and the battery and get a reading of .085 regardless of which fuse I pull.

Does anyond have a system I can use to follow to get to the short??

I REALLY need help.

Thanks JohnnyJ

0.085 amps? I don't have a clue what it should read, but 0.085 amps doesn't seem like much. I checked in my old C4 shop manual, but I couldn't find any numbers.

 

[zgator]

I had a 71 454 monte carlo that did that and it truned out to be the ingition switch?

 

[goingballistic]

As stupid as this may sound, I had a very similar problem last year. My oldest son noticed a "glow" under the rear end of my car when it was parked in the driveway at night..............it turned out to be a small light near the spare tire under the rear of the car. The light is practically worthless for seeing anything but turned out to be what was draining my battery. I had disconnected every light in my car and not knowing that one was there, it drove my nuts......thank god for young eyes.


As far as the amperage draw on the battery, I am assuming you are reading the amps in line ie the battery is disconnected and you have the meter "between" the hot lead and what you are checking........you can't read amperage draw "across" something..............if you had a short to ground the amperage would be much higher than what you are reading.

 

[76okievette]

Hey, the problem with my '76' was in the alarm circuit, I did not find it but the guy at the local corvette shop did, he unplugged the alarm relay and it stopped the drain. It seems the alarm was shorted and providing a ground to the power side of circuit all the time. Hope this helps.