Low Voltage Light and Buzzing Until Key Turned
Thread Starter
Intermediate
Joined: Aug 2016
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From: Virginia
Low Voltage Light and Buzzing Until Key Turned
So My new project a Corvette 1981 C3 has many issues but the first project I am addressing is once the battery is connected the low voltage light turns on and a buzzer comes on. This is before I have even put in the key. Once I put in the key it stays on until I turn the key to the first position, then the buzzer and light go away and I can start the car normally. It starts with no issue. So I got a new battery appropriate for the car as the old one was rather old but this didn't change the issue. I disconnected the door a jar sensors and the hood one just to see if it was really one of those but no change.
Last edited by mmcfearin; Aug 20, 2016 at 05:09 PM.
Le Mans Master
Joined: Aug 2006
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From: mount holly NC
2025 c3 ('74-'82) of the Year Finalist - Unmodified
2019 C3 of Year Finalist (appearance mods)
Hi and Welcome!
So My new project a Corvette 1981 C3 has many issues but the first project I am addressing is once the battery is connected the low voltage light turns on and a buzzer comes on. This is before I have even put in the key. Once I put in the key it stays on until I turn the key to the first position, then the buzzer and light go away and I can start the car normally. It starts with no issue. So I got a new battery appropriate for the car as the old one was rather old but this didn't change the issue. I disconnected the door a jar sensors and the hood one just to see if it was really one of those but no change.
An 81 Service manual and the Assembly instruction manual (AIM) will pay for themselves many times over.
Here's an 81 schematic:
https://docs.google.com/viewer?a=v&p...TkzNDc2YzgzNGU
Team Owner
Joined: Jan 2006
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From: Crossville TN
Your problem could be the switch in the steering column head (with the ignition switch); or it could be a defective horn relay. The horn relay provides the buzzer action (at least, it does with the early C3's).
The 'low voltage' problem is most likely bad battery cables, connections, and/or grounds (if the battery is in good condition). Grounding on the ECM is particularly important.
The 'low voltage' problem is most likely bad battery cables, connections, and/or grounds (if the battery is in good condition). Grounding on the ECM is particularly important.
Thread Starter
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From: Virginia
Thanks, I will look into that first, I didn't mention that the horn wasn't working, didn't think it was relevant but I didn't know the horn relay was in the mix. I just ordered two service manuals. ^_^ thanks for your time team.
Thread Starter
Intermediate
Joined: Aug 2016
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From: Virginia
So it was a relay under the center console. Buzzing its little tail off. A green relay, removed it and no buzz. The low voltage light is still on. Note this all happens once the battery is connected, the key is not in the ignition. Once I put the key in it keeps doing this until I turn it to the "run" position then the dash light goes off and the buzz stops.
Thanks for the relay tip. I can at least now continue to work on the car without hearing that darn buzz.
Thanks for the relay tip. I can at least now continue to work on the car without hearing that darn buzz.
Thread Starter
Intermediate
Joined: Aug 2016
Posts: 25
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From: Virginia
Did a bit of reading and it looks like the relay I removed is the "Engine Choke Relay" would this indicate it is bad? Did not actually try to start the car after removing this but it always starts first time every time.
