Persistent failure to charge battery
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Topic author - Posts: 11
- Joined: 11/08/13 18:02
Persistent failure to charge battery
Can anyone help resolve an ongoing battery charge issue I am having with my 1989 Mk1b? A few weeks ago I came to start the car and the battery was completely dead. As it was approx 8 years old I have replaced it with a new 50A 420CCA YUASA. Once the new battery was in I got the engine bay fan / charge lights on the dashboard. I do not remember the lights showing last time it was driven, which was a 50 mile run. Taking advice from previous threads I have investigated the following:
- A voltmeter across the battery terminals shows a steady 12.4V - no increase to 13.5V+ when engine running
- Fuses AM2, Charge and Engine - checked and all OK
- In-lne link to battery +ve terminal checked and intact (as far as I can tell)
- Each pin on the alternator plus checked with the ignition on (engine not running) - reading approx 12.4V all pins
- Positive terminal on alternator checked with ignition on - 12.4V showing
- Assuming a faulty volage controller (and not wiring) I have swapped the voltage controller, bush block and regulator from a second unit into the alternator (which was working fine when the bearing seized) but the same symptoms persist
Is there anything I have missed? I have run out of ideas.
Many thanks for your thoughts
- A voltmeter across the battery terminals shows a steady 12.4V - no increase to 13.5V+ when engine running
- Fuses AM2, Charge and Engine - checked and all OK
- In-lne link to battery +ve terminal checked and intact (as far as I can tell)
- Each pin on the alternator plus checked with the ignition on (engine not running) - reading approx 12.4V all pins
- Positive terminal on alternator checked with ignition on - 12.4V showing
- Assuming a faulty volage controller (and not wiring) I have swapped the voltage controller, bush block and regulator from a second unit into the alternator (which was working fine when the bearing seized) but the same symptoms persist
Is there anything I have missed? I have run out of ideas.
Many thanks for your thoughts
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Topic author - Posts: 11
- Joined: 11/08/13 18:02
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Re: Persistent failure to charge battery
That was your mistake, never assume the tests you did all pointed to a faulty alternator. Which could have been a faulty VR, but once you had swapped that out your only left with alternator (either an O/C or S/C on the windings) No matter your sorted now