Weird electrical problem
Thread Starter
Racer
Joined: Apr 2016
Posts: 335
Likes: 92
From: San Antonio TX
Weird electrical problem
So, took my 1989 C4 out for a drive today to get the State Inspection done. Started fine, drove fine. Came back to home base and shut it off to get out and open the garage door (no remote). Got back in to start it and everything is dead. No cluster lights, no interior lights, engine won't crank. Battery is fairly new and measured 12.1 volts.
Also, there was a humming noise coming from the passenger side of the dash, couldn't really localize it better. It was making the noise even with the key out! The only thing that would get it to stop was disconnecting the battery.
I was thinking maybe I blew one of the fusible links, but what the heck is making the hum/buzz. Didn't really have time to proceed further today, but thought I would ask if anyone else has had something like this happen. I do have the CSM.
Steve
Also, there was a humming noise coming from the passenger side of the dash, couldn't really localize it better. It was making the noise even with the key out! The only thing that would get it to stop was disconnecting the battery.
I was thinking maybe I blew one of the fusible links, but what the heck is making the hum/buzz. Didn't really have time to proceed further today, but thought I would ask if anyone else has had something like this happen. I do have the CSM.
Steve
Last edited by NavAir; Dec 17, 2016 at 08:46 PM.
Safety Car
Joined: May 2001
Posts: 4,721
Likes: 1,626
From: Fairfax Virginia
Battery power issues
Did you remove the battery and have it load tested? It might be a good thing to try as the open circuit voltage of the battery should be 12.5-12.7 if in decent condition. A battery that has been heavily oxidized internally can show full voltage when it is sitting but as soon as you put a load on it the voltage drops like a rock. If you tried starting the car fairly soon after running that battery should have a higher open circuit voltage. Batteries oxidize the fastest when left for time at a low state of charge or low on electrolyte.
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
Instructor
Joined: Jun 2013
Posts: 225
Likes: 1
From: hanceville al
Did you remove the battery and have it load tested? It might be a good thing to try as the open circuit voltage of the battery should be 12.5-12.7 if in decent condition. A battery that has been heavily oxidized internally can show full voltage when it is sitting but as soon as you put a load on it the voltage drops like a rock. If you tried starting the car fairly soon after running that battery should have a higher open circuit voltage. Batteries oxidize the fastest when left for time at a low state of charge or low on electrolyte.
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
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Thread Starter
Racer
Joined: Apr 2016
Posts: 335
Likes: 92
From: San Antonio TX
Did you remove the battery and have it load tested? It might be a good thing to try as the open circuit voltage of the battery should be 12.5-12.7 if in decent condition. A battery that has been heavily oxidized internally can show full voltage when it is sitting but as soon as you put a load on it the voltage drops like a rock. If you tried starting the car fairly soon after running that battery should have a higher open circuit voltage. Batteries oxidize the fastest when left for time at a low state of charge or low on electrolyte.
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
I bought a car battery at Costco and it lasted less than a year in my 1988 Corvette. It was simply a piece of junk, now all I use are Interstate brand batteries in everything I own. Back to the 4-5 years of lifetime without any issues.
When a car has a serious low voltage situation the Relays will sometimes "Buzz" which sounds strange. There are several relays in the center of the dashboard able to produce this sound.
I left my 1988 under a cover for a couple years and when I tried to start it with a brand new battery I got nothing inside the dashboard area. It turned out to be corrosion on the post located between the drivers door and the battery. On my car this is where the fusible links all get their power (+12 Vdc). I removed the terminals and cleaned each one and then the post as well. It takes a few minutes to do it right and get all the contact surfaces nice and shiny, then use some Die-electric grease to coat the parts and reassemble. Once you have done this you do the same thing to every battery ground strap/connection you can find.
I was amazed at the voltage drops that existed between the battery and the radio and other accessories.
Last but not least check for clean connections at the fuse block, I removed each fuse and cleaned the terminals with Emory cloth. After the connections were cleaned everything worked like new. I have several fuses that had corrosion on the blades which showed no continuity even though the fuses were not blown. Next time I will remember to buy better fuses....
Good Luck and Merry Christmas!
Thread Starter
Racer
Joined: Apr 2016
Posts: 335
Likes: 92
From: San Antonio TX
Turns out that it was the common connection for most of the fusible links. (Inboard of the battery, so tough to see with the battery installed). None of them were burned, but the nut securing them to the post had somehow loosened. Took about 30 seconds to fix. Fired right up after that.
Steve
Steve