Battery Drain
Thread Starter
Heel & Toe
Joined: Aug 2004
Posts: 23
Likes: 0
Battery Drain
Hi Guys,
I have an 84 that has a serious battery drain. 36 hours sitting will kill it, maybe less. My dash is messed up as usual and my mechanic disconnected it as the source of the drain. But it is not the case. I parked the car on Friday at 6 p.m., Sunday at 2 p.m. there was no power.
Has anyone had this kind of drain? I have an aftermarket alarm, mechanic said that it is not drawing that much power. I even put a high performance alternator in the car (150 amp). Still no help. Battery is 3 weeks old.
I am at wits end. Any advice is aapreciated. Thanks.
Jeremy
I have an 84 that has a serious battery drain. 36 hours sitting will kill it, maybe less. My dash is messed up as usual and my mechanic disconnected it as the source of the drain. But it is not the case. I parked the car on Friday at 6 p.m., Sunday at 2 p.m. there was no power.
Has anyone had this kind of drain? I have an aftermarket alarm, mechanic said that it is not drawing that much power. I even put a high performance alternator in the car (150 amp). Still no help. Battery is 3 weeks old.
I am at wits end. Any advice is aapreciated. Thanks.
Jeremy
Le Mans Master
Joined: Sep 2002
Posts: 8,991
Likes: 2
From: Hanger 18 Taxachusetts
might want to put a current meter inline with the + side of the battery to see how much current is flowing.
Not sure what the norm is but it can't be much.
Then go to the fuse panel and start pulling them one at a time.
Check the current draw after each one you pull out until you find the line that is drawing high current.
Your on your own from that point to find out what on the line has changed??
Not sure what the norm is but it can't be much.
Then go to the fuse panel and start pulling them one at a time.
Check the current draw after each one you pull out until you find the line that is drawing high current.
Your on your own from that point to find out what on the line has changed??
Burning Brakes
Joined: Oct 2004
Posts: 1,094
Likes: 0
From: West Palm Beach Florida
Here is how I always check current draws:
1) disconnect the battery poss terminal.
2) disconnect the pass door switch (so you could have the door open for test)
3) install a test light between the battery terminal and the battery post.
4) while test light is in place touch the battery terminal to the battery post (to deenergise any relays)
5) go to the fuse panel and pull the fuses one by one checking the test light on each fuse pull.
6) when the test light goes out... YOU HAVE THE CIRCUIT!!!
7) now go trace your circuit... possibly removing items on the circuit till the test light goes out.
Its not hard to do and if you can do it yourself you will save a bundle of money. Figure your mechanic is going to charge you by the hour for as long as it takes to find the problem. THAT WILL ADD UP QUICK!!!
I would go after the easy and obvious stuff first... interior lights, glove box lights, console lights and hood lights.
1) disconnect the battery poss terminal.
2) disconnect the pass door switch (so you could have the door open for test)
3) install a test light between the battery terminal and the battery post.
4) while test light is in place touch the battery terminal to the battery post (to deenergise any relays)
5) go to the fuse panel and pull the fuses one by one checking the test light on each fuse pull.
6) when the test light goes out... YOU HAVE THE CIRCUIT!!!
7) now go trace your circuit... possibly removing items on the circuit till the test light goes out.
Its not hard to do and if you can do it yourself you will save a bundle of money. Figure your mechanic is going to charge you by the hour for as long as it takes to find the problem. THAT WILL ADD UP QUICK!!!
I would go after the easy and obvious stuff first... interior lights, glove box lights, console lights and hood lights.
Burning Brakes
Joined: Oct 2004
Posts: 1,094
Likes: 0
From: West Palm Beach Florida
[QUOTE=corvette-pilot]might want to put a current meter inline with the + side of the battery to see how much current is flowing.
[QUOTE]
This is a good idea but for someone who is not comfortable around a DVOM they might have a problem... I would advise to stick with a good test light.
[QUOTE]
This is a good idea but for someone who is not comfortable around a DVOM they might have a problem... I would advise to stick with a good test light.
Thread Starter
Heel & Toe
Joined: Aug 2004
Posts: 23
Likes: 0
Hi Guys,
Thanks for the advice. I have tried the test light on the battery with my mechanic. We started to pull fuses one by one and did not find the problem. The test light is very bright, meaning a lot of juice is being pulled. He did say that my interior lights were staying on, but I do not see it making a difference when the fuse is pulled.
Driving me nuts. Maybe I will just leave the car running in Miami with the doors open. Let my insurance company buy the car. lol j/k
Thanks guys.
Thanks for the advice. I have tried the test light on the battery with my mechanic. We started to pull fuses one by one and did not find the problem. The test light is very bright, meaning a lot of juice is being pulled. He did say that my interior lights were staying on, but I do not see it making a difference when the fuse is pulled.
Driving me nuts. Maybe I will just leave the car running in Miami with the doors open. Let my insurance company buy the car. lol j/k
Thanks guys.
Team Owner
Joined: Mar 2001
Posts: 54,124
Likes: 30
From: Cincinnati, Oh USA
Leakage current (battery current with everything off) should be less than 50 milliamps (my 87 draws 27 ma.). First check at night if the under hood lights are on or if the console compartment light is on or the vanity mirror lights are on. Disconnect add on electronics like your alarm, audio amplifiers, radar detectors etc. Several CFers found their aftermarket alarms were at fault(why add ANOTHER alarm? C4's already have an alarm). A leaky alternator rectifier can draw current, so disconnect the large red output wire on the alternator (disconnect the battery neg cable because the alt wire is connected to the battery positive post all the time and a wrench hitting ground will blow its fusible link). Several CFers also found their seat adjust switches were stuck on discharging their battery.
Not all circuits have a removable fuse. Behind your battery is a battery jumper terminal and their are about 8 wires under its nut and these circuits have a fusible link. Remove the nut and remove these wires one at a time while observing the battery leakage current. Trace the one that drops the leakage current upon removal. Good Luck.
Not all circuits have a removable fuse. Behind your battery is a battery jumper terminal and their are about 8 wires under its nut and these circuits have a fusible link. Remove the nut and remove these wires one at a time while observing the battery leakage current. Trace the one that drops the leakage current upon removal. Good Luck.
Last edited by jfb; Dec 13, 2004 at 11:15 PM.
Team Owner
Joined: Sep 2003
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From: Freedom is never more than one generation away from extinction.
St. Jude '03 thru '24
Did you check to see if the vanity mirror light has been left on?
I walked around the car in the dark of night and looked for any sign of light. Thats how I know that darn light is easy to miss.
Gd'luck
-JRC-
I walked around the car in the dark of night and looked for any sign of light. Thats how I know that darn light is easy to miss.
Gd'luck
-JRC-
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Melting Slicks
Joined: Apr 2002
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From: North Aurora Il
Test it with a meter. Put it on dc amps. I use vise grips to hold the probes on the battery post and the post clamp. You have to get all the lights off. Stick a block of wood against the pass. door switch. Then pull fuses, noting the current draw each time.
On my truck I have about a .5 amp draw and the bat. goes dead in about 10 days. Mine is in the ignition off draw circuit which has about 15 things on it, I gave up. You're probably drawing at least 3 amps.
You'll need the meter on there when you are tracing the bad circuit. You can grab the wires and shake them and see the current changing when you get close.
On my truck I have about a .5 amp draw and the bat. goes dead in about 10 days. Mine is in the ignition off draw circuit which has about 15 things on it, I gave up. You're probably drawing at least 3 amps.
You'll need the meter on there when you are tracing the bad circuit. You can grab the wires and shake them and see the current changing when you get close.
Le Mans Master
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From: DrunkDefender
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I just went through this at work on an 84. Your car likely doesnt have the stud behind the battery with a bunch of wires coming off of it like on some later C4s. Your electrical distribution point may be on the starter. I used my Fluke DVM between the pos battery post hooked up in series to watch the current draw. Just dont try to power up/start the whole car on your meter (long stary but it does bad things even when you're fused). With the interior lights on you'll draw about 3.5A. It should power down to less than 50Ma. Mine turned out to be the security system. Theres a fuse located behind your info select center(or whatever you call it, the place where you select which values to display on the dash ie: volts, mpg, range, etc etc) Pull that and look behind it for a 10amp fuse. Pull it and see of your draw doesnt go away.
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Originally Posted by corvette-pilot
might want to put a current meter inline with the + side of the battery to see how much current is flowing.
Not sure what the norm is but it can't be much.
Then go to the fuse panel and start pulling them one at a time.
Check the current draw after each one you pull out until you find the line that is drawing high current.
Your on your own from that point to find out what on the line has changed??
Not sure what the norm is but it can't be much.
Then go to the fuse panel and start pulling them one at a time.
Check the current draw after each one you pull out until you find the line that is drawing high current.
Your on your own from that point to find out what on the line has changed??
The current flowing in this state, with everything turned off is parasitic. As stated in another response it should not be less then 50mA. You can purchase an inexpensive dmm (digital multi meter) from several places, Radio Shack comes to mind. A test light will not work. A test light uses voltage to illuminate a bulb. It will tell you where there is voltage but will give you no clue as to the true current draw.
Try this. If you are confused, send me a pm and I will call you or give you my mobile number and help walk you through it.
Good luck,
Larry
Thread Starter
Heel & Toe
Joined: Aug 2004
Posts: 23
Likes: 0
Thank You
Hi Guys,
Thanks for all the advice. The only aftermarket item installed now is the a Prestige alarm. My mechanic says that the power drain is not the alarm. But he is also a general mechanic, not an electronics specialist.
The problem is that I live in a condo and do not have an alarm. I do have a battery tender that worked great for me years ago when I had a garage. But I do not have access to an outlet in my current situation. I am thinking about getting a C5 and do not want to put too much $ into the 84. Thanks for all your help. I am new to this forum and think it is a great tool and community.
Best Regards,
Jeremy
Thanks for all the advice. The only aftermarket item installed now is the a Prestige alarm. My mechanic says that the power drain is not the alarm. But he is also a general mechanic, not an electronics specialist.
The problem is that I live in a condo and do not have an alarm. I do have a battery tender that worked great for me years ago when I had a garage. But I do not have access to an outlet in my current situation. I am thinking about getting a C5 and do not want to put too much $ into the 84. Thanks for all your help. I am new to this forum and think it is a great tool and community.
Best Regards,
Jeremy
