'1994 E350 alternator charging?
Started the engine for the first time in 3 months. The dash light for the charging circuit goes out when the engine is running but the voltage reads 12.5 (on several meters.) I noticed previously last...
Forum Discussion
The 70 and 90 ampere models of alternator for this chassis use an EXTERNAL voltage regulator. The very next year Ford started using the large frame 3G alternator with the voltage regulator integrated with the alternator.
The second generation large frame alternator has two weaknesses. The first is brushes that are too short. There is no remedy for this. The second weakness is the stator wire terminals are CRIMPED onto tiny ring terminals (#4) which in turn are soldered onto the rectifier plate. Those wires (Delta configured with the 90 amp stator) MUST BE SOLDERED TO THE STATOR WIRES or they will fail. The crimped on terminals get so hot it actually anneals the copper stator wires. TRANSPO ELECTRONICS devised a rather pricey rectifier plate that uses #8X32 studs and nuts, but did nothing to address the real source of the problem.
The subsequent 3G, 4G, and 6G alternator models all use SOLDERED connections between stator wires and rectifier plate.
One of the best mods you can do to a motorhome with an older 70-90 amp alternator is to replace it with a 130 amp 3G. The unit is absolutely bolt on, and only a wire harness mod is necessary to adapt the regulator. The early alt charges perhaps 30 amps at dead idle, the 3G charges 70-90 amps at dead idle. And 40 more amperes ultimate potential. The 6303 and A2000XX rear bearings will carry three times the load of the original's 6203, and MNJ671 torrington bearings. Three times the bearing life.
Later 4G, and 6G models use a different bolt mounting pattern and really do not offer any real gain.
The second generation large frame alternator has two weaknesses. The first is brushes that are too short. There is no remedy for this. The second weakness is the stator wire terminals are CRIMPED onto tiny ring terminals (#4) which in turn are soldered onto the rectifier plate. Those wires (Delta configured with the 90 amp stator) MUST BE SOLDERED TO THE STATOR WIRES or they will fail. The crimped on terminals get so hot it actually anneals the copper stator wires. TRANSPO ELECTRONICS devised a rather pricey rectifier plate that uses #8X32 studs and nuts, but did nothing to address the real source of the problem.
The subsequent 3G, 4G, and 6G alternator models all use SOLDERED connections between stator wires and rectifier plate.
One of the best mods you can do to a motorhome with an older 70-90 amp alternator is to replace it with a 130 amp 3G. The unit is absolutely bolt on, and only a wire harness mod is necessary to adapt the regulator. The early alt charges perhaps 30 amps at dead idle, the 3G charges 70-90 amps at dead idle. And 40 more amperes ultimate potential. The 6303 and A2000XX rear bearings will carry three times the load of the original's 6203, and MNJ671 torrington bearings. Three times the bearing life.
Later 4G, and 6G models use a different bolt mounting pattern and really do not offer any real gain.
