Battery discharge on 1990 Mitsubishi Galant


#1

I need a diagnosis. My Galant was running fine, but was parked for a few days and when I tried to start it it would not turn over at all–totally dead. I thought I had run it down because a door was ajar. I had the battery checked out, it was ok and took a charge. I reinstalled it and attempted to start my car 45 minutes later, once again my car would not turn over. What could be discharging the battery?


#2

I would be suspicious of the battery, even though 'it was o.k. and took a charge". You might have the battery recharged again and start the car. Run the car for a while, then shut it off and disconnect the negative cable. After an hour, reconnect the cable and see if you can start the car. If you can, there is a current drain in the car. If the car won’t turn over, the battery is no good.


#3

How old is that battery? How clean are the battery cables (all cables, all ends)? It takes a while to hunt down a large drain, so let’s rule out a few other things.

If those don’t find anything, then you want to turn the car off and put a amp meter on the battery and start pulling fuses one at a time to start narrowing down what is using juice. On some cars you need to leave the car off for a while (like 30 minutes) before you can get good readings.


#4

Some more info is needed. Headlights work? Dashboard warning indicator lamps working? Any starter solenoid click sound?


#5

I’d suspect the battery too or bad connections to the battery. Personally, I don’t trust the battery testers depending on who did it. I had one last winter on a car that sat most of the time. Worked fine, charged it for a few days, went to deliver it to the buyer and wouldn’t even turn the starter over. It was only a couple years old. WalMart said it was borderline but only registered 11 volts. They gave me a new one but weren’t convinced it was bad based on their testing. Batteries can be deceiving so if its a few years old, I’d just replace it for the $60 first. If it still discharges, you can start the harder process of looking for the short.


#6

Your comment about Wal Mart reminded me of a deal I was into with them a few years ago in regards to a battery. The battery was less than one year old and would go completely dead in 2-3 days at the maximum.

Of course, I tested the alternator, checked for a parasitic draw, etc. with no problems present.
I could place that battery on a benchtop, fully charge it, and 24 hours later it would not start a car. Hit the starter a few seconds and it would register about 9-10 volts almost instantly.

I took that battery into WM twice and they insisted both times it was good along with harping on “are you sure the alternator is good”, “maybe you have a bad starter”, “clean the cables”, etc.
Jeez! What part of going dead overnight on a benchtop do you not understand!

Since they wanted to play hardball I drilled a 1/32 hole in the bottom of one of the cells, drained the electrolyte out, sealed the hole with black RTV, and voila; battery with a bad cell, no ifs, ands, or buts. They replaced it as they should have under the pro-rated terms and no more problems with the car.

Normally, I’m not unethical but in this case Wal Mart just totally steamed me; especially when the guy doing the testing started talking about his battery schooling qualifications.


#7

Dilbet cartoons are written from true stories like that.


#8

Since I first posted this problem I have charged the battery w/ a trickle charger,reinstalled it and ran the car for about 10 minutes. I then shut it off and disconnected the neg.cable. After about an hour I attempted to restart the car and once again it did not start. I pulled the battery and trickle charged it again and it registered as fully charged in 10 minutes. I then reinstalled the battery and this time my car did not start. The dashboard lights flashed on as I turned the key, my overhead light was working, and the auto seatbelt was attempting to run. There was no clicking sound this time, but there had been a clicking sound when I’d tried to once again start the car before I’d pulled the battery to charge it on the trickle charger. I’d attempted to start it because, as I was disconnecting the battery, every time I touched the negative cable I could hear a beeping sound inside the car (I think it was from my auto seatbelt mech.), and I wondered if there might be enough juice to start. Anyway, it has made me suspicious that my auto seatbelt on the driver’s side may be the source of a drain. The battery was new in June 2002 and my starter is 2 or 3 years old. I am still hoping it is the battery, as that will be much easier to solve


#9

I doubt if it is the seat belt system. At this time it could be the battery, cable or connections.

every time I touched the negative cable I could hear a beeping sound inside the car
This makes me suspect that negative cable. I would suggest replacing it. They can go bad internally and it is likely 18 years old. Be sure to carefully clean where it attaches at both ends before when replacing the cable. Do it even if they look clean.

The battery was new in June 2002

I would also likely replace the battery. It is six years old now and that is old enough to cause it to also be suspect.