Batt Gauge/Charging/Discharging
Team Owner
Joined: Jul 2008
Posts: 23,419
Likes: 22
From: In limbo
St. Jude Donor '13-'15, '17 thru '22
There seems to be a rash of these lately!
I inadvertently fixed mine by taking the battery out and putting it back in. I think the problem was I was not getting really good contact at the battery terminals. So I would check that first. Disconnect the battery, and do a load test on it. As Alan's post details, the system is supposed to change its charging/discharging habits based on the condition of the battery, so while you have it disconnected, you might as well make sure you're using a good battery. I didn't have a load tester, so while it was disconnected, I took it to Advance Auto Parts, where they load test it for you for free.
If you have never done it, I would take off the left rear wheel, find the grounding strap where it bolts to the frame, unbolt it, clean it up real good to make sure you have good connection, and bolt it back on. As these cars are approaching half a century old, it really can't hurt.
It wouldn't be a bad idea to do the same thing to the grounding strap from the engine to the frame. This one is a little harder to get at since I need to jack up the car to reach it, but still not that big of a deal.
At this point, you know you have a good battery, and all your "big grounds" should be working well. I would make sure the battery is fully charged, and start the car. I would then test the voltage at the alternator, and at the battery connections. They should be almost exactly the same. Alan said a different range than I am used to, I have heard you want 13.7 to 14.7 volts from the alternator. Mine were both 14.5.
I inadvertently fixed mine by taking the battery out and putting it back in. I think the problem was I was not getting really good contact at the battery terminals. So I would check that first. Disconnect the battery, and do a load test on it. As Alan's post details, the system is supposed to change its charging/discharging habits based on the condition of the battery, so while you have it disconnected, you might as well make sure you're using a good battery. I didn't have a load tester, so while it was disconnected, I took it to Advance Auto Parts, where they load test it for you for free.
If you have never done it, I would take off the left rear wheel, find the grounding strap where it bolts to the frame, unbolt it, clean it up real good to make sure you have good connection, and bolt it back on. As these cars are approaching half a century old, it really can't hurt.
It wouldn't be a bad idea to do the same thing to the grounding strap from the engine to the frame. This one is a little harder to get at since I need to jack up the car to reach it, but still not that big of a deal.
At this point, you know you have a good battery, and all your "big grounds" should be working well. I would make sure the battery is fully charged, and start the car. I would then test the voltage at the alternator, and at the battery connections. They should be almost exactly the same. Alan said a different range than I am used to, I have heard you want 13.7 to 14.7 volts from the alternator. Mine were both 14.5.
