P0625 battery light on Ford Fusion

Diagnose and fix P0625 and battery light on Ford Fusion

Step by step testing for Ford Fusion alternator

The alternator on 2014 and later Ford Fusion vehicles has an internal voltage regulator. A P0625 code relates to the charging system and the battery light may be on.

Start by checking voltage at the battery terminals with electrical loads turned on—blower, heated seats, defogger, etc. A voltage reading of 13.5 volts or more indicates charging. This vehicle is equipped with power management so the alternator will not charge if it does not require charging. Putting a load on the system will activate the charging mode.

If the alternator isn’t charging

With the engine off, disconnect the 3-wire connector going to the internal voltage regulator in the alternator. Then start the engine and rev the engine to 2500RPM for a short period while you check voltage at the battery. Look for at least 13.5 volts.

If the alternator does not charge with the voltage regulator disconnected and the engine rpm at 2500, there may be an open in the either the battery conductor or the ground. Use jumper wires to connect a jumper from the battery terminal on the back of the alternator and clamp the other end directly to the battery positive terminal. Then connect a second jumper wire to the alternator case, with the other end connected to the battery negative terminal. Check battery voltage to see if the alternator is charging. If not, replace the alternator.

If the alternator does charge with the voltage regulator disconnected

Check the brown/red wire in the voltage regulator connector. You should see battery voltage. If not, check fuse #55 10A located in the battery junction box.

©, 2018 Rick Muscoplat