With the wire disconnected, usually the alternator will revert to internal control like an older unit. The exact voltages will vary depending on manufacturer. But will still be in the lead-acid limits above. 13.5 on idle may be normal, but it should rise to over 14v with a few rpm.
2. Name: Chris. Ford Model: Focus 1.8 tdci. Ford Year: 2009. UK/Ireland Location: Leicestershire. Posted March 7, 2022. Have recently purchased the above car as a cheap runaroundcouple of issues with it including new alternator but still having a starting problem. 1st start of the day was taking between 5-10 minutes, turned over fine but no
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