Got a weird electrical problem
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4th Gear
Joined: Sep 2007
Posts: 4
Likes: 0
Got a weird electrical problem
Hi there. This is my first post. I have 71 Vette, 350/270, 4 speed, air, and unmodified. It has been sitting in my garage and not started for about four months so the battery was dead (clock I guess). I put the charger on it this morning for three hours. Here is the weird part. When I got in to start it, there was a strange harmonic hum in the radio as I turned the key on. It hummed about 1 second then stopped. I turned the key off. Each time I turned the key on, the hum would come from the speakers then stop. Then I tried to start the car and got a loud buzzing noise that seemed to be coming from above the passenger foot well or just to the right of the center instrument cluster. Each time I tried to crank it, I got the buzz and it would stay as long as I held the key in the start position. The car would not start as the starter never turned. I was worried about damaging the electrical system so I disconnected the charger, tried it (starting) again just to see what would happen but the system was totally dead as if the battery was disconnected. I haven't put the charger back on for fear of screwing up something or starting a fire.
Do any of you guys have any idea what the problem might be because I am not an electrical guy and I am completely dumb founded. Thanks in advance.
Do any of you guys have any idea what the problem might be because I am not an electrical guy and I am completely dumb founded. Thanks in advance.
Melting Slicks
Joined: May 1999
Posts: 2,897
Likes: 0
From: Moon Township PA
I agree and am guessing that this battery is so old that it won't take a charge or hold one. Have you checked the electrolyte level in the battery to see if it evaporated?
Go to Advance Auto, buy a generic battery and go have fun. OR, borrow a battery from a friend and try it at home?
Gary
Go to Advance Auto, buy a generic battery and go have fun. OR, borrow a battery from a friend and try it at home?
Gary
Burning Brakes
Joined: Feb 2004
Posts: 924
Likes: 2
From: Kearneysville West Virginia
If the battery has been dead for that long, you need to put it on charge for much longer than three hours before trying to start it. Sometimes, when batteries are dead for a long time, they will not come back. But, most times they will, but the process starts off very slow. Let the battery charge for a day before you try and start it. If you have an ammeter on your charger, you might notice that the charger appears to not be charging at first. This is because the battery starts out taking in very little current, milliamps. After a while, if the battery is going to come back, the charging current will slowly increase, and show some amps, maybe 5-10 amps.
The buzz you heard was the 60 hertz or possibly 120 hertz from the battery charger. The battery was completely dead, so it was transparent. All your car was seeing at the time was the output of the charger, which is not all clean DC like would come from a battery. The output from the charger is unfiltered rectified AC, which depending on the rectifier used by the charger, will produce 60 or 120 hertz noise on top of the DC charging voltage.
So, first, let the battery charge a day before you try to start it again. If the battery does not come back, it is time for a new battery. I hope this helps.
The buzz you heard was the 60 hertz or possibly 120 hertz from the battery charger. The battery was completely dead, so it was transparent. All your car was seeing at the time was the output of the charger, which is not all clean DC like would come from a battery. The output from the charger is unfiltered rectified AC, which depending on the rectifier used by the charger, will produce 60 or 120 hertz noise on top of the DC charging voltage.
So, first, let the battery charge a day before you try to start it again. If the battery does not come back, it is time for a new battery. I hope this helps.
