Battery drain...antenna problem
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Joined: Mar 2001
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From: ca
Battery drain...antenna problem
For several months I have had a periodic problem with either a low or dead battery. The '87 Coupe 4+3 is only driven about once a week, but sometimes even after 2-3 days there isn't enough power left to crank the engine over. I've had to replace the Alt several times in past years due to shorted internal diodes. This was different.
The title may be misleading. The antenna works fine.
My first attempt at trouble shooting the problem found a battery drain of close to 10amps at the battery that would come and go. Ten second drain, twenty seconds off and it repeated the cycle consistently. The 10 amps would ride above the drain for hatch light and interior lights, timed out or not.
When the amp meter at the battery flipped high, low, and back, I could hear a faint click at the rear of the car. I could not tell where it was coming from. Could not hear it in the brake controller box. It was not the fuel pump as I removed its relay. The antenna relay was not clicking. Voltage to it, from the courtesy fuse was constant and the line to the radio was 0 V as it should be. Besides, it ran up and down as it should.
Short story long, it took me forever to find the clicking. Sometimes the clicking/drain would go away on it's own for weeks at a time. At other times, I would just charge the battery and drive it.
Yesterday, I finally got serious and found the problem.
Who knew the antenna has an auto-reset circuit breaker inside? It was right there in front of me in the antenna section of the manual, but it never registered. It also says the motor draws 3.0 amps running and the stall current is 10.5 amps. 10 amps and a circuit breaker fits my symptoms and a light finally went on.
The thrust blocks are supposed to flip the switches off when the mast is down and motor stalls and apparently mine is not.
Grounds and voltages in and out of the relay are as they should be in both up and down modes.
I am confident I have not posted this prematurely and I have ordered a new antenna and it's on backorder. I decided to get the '88 and up Harada that is sold as an upgrade for '84-'87 by many of the vendors. They claim better reception and decided not to fart with the old.
I did a search and found this thread. Sounds similar, but it was never brought to a conclusion.
http://forums.corvetteforum.com/show...=antenna+short
The title may be misleading. The antenna works fine.
My first attempt at trouble shooting the problem found a battery drain of close to 10amps at the battery that would come and go. Ten second drain, twenty seconds off and it repeated the cycle consistently. The 10 amps would ride above the drain for hatch light and interior lights, timed out or not.
When the amp meter at the battery flipped high, low, and back, I could hear a faint click at the rear of the car. I could not tell where it was coming from. Could not hear it in the brake controller box. It was not the fuel pump as I removed its relay. The antenna relay was not clicking. Voltage to it, from the courtesy fuse was constant and the line to the radio was 0 V as it should be. Besides, it ran up and down as it should.
Short story long, it took me forever to find the clicking. Sometimes the clicking/drain would go away on it's own for weeks at a time. At other times, I would just charge the battery and drive it.
Yesterday, I finally got serious and found the problem.
Who knew the antenna has an auto-reset circuit breaker inside? It was right there in front of me in the antenna section of the manual, but it never registered. It also says the motor draws 3.0 amps running and the stall current is 10.5 amps. 10 amps and a circuit breaker fits my symptoms and a light finally went on.
The thrust blocks are supposed to flip the switches off when the mast is down and motor stalls and apparently mine is not.
Grounds and voltages in and out of the relay are as they should be in both up and down modes.
I am confident I have not posted this prematurely and I have ordered a new antenna and it's on backorder. I decided to get the '88 and up Harada that is sold as an upgrade for '84-'87 by many of the vendors. They claim better reception and decided not to fart with the old.
I did a search and found this thread. Sounds similar, but it was never brought to a conclusion.
http://forums.corvetteforum.com/show...=antenna+short
