87-278-4 September 1996 Ford 4G Alternators: An Overview In 1995, Ford introduced a new series of alternators known as the 4G. The first applications were on the 1995 Lincoln Continental with a 4.6L V8 engine. Then in 1996, 4G-series alternators began appearing on a number of other models. To date, these alterna- tors are all 130-amp. Unusual Mounts The original units in this series, which were used on Lincoln Continental, have a saddle mount (Figure 1). At first, these saddle-mount units had round mounting holes (Ford #F5OU-10300-FA). Then Ford changed to the slotted mounting holes shown in Figure /, but kept the same basic part number, changing only the last letter (Ford #F5OU-10300-FB). The WAI number for these saddle-mount units is 1-1904-11FD. Inside the 4G When you remove the cover of a 4G alternator, you will see that it has a small slip ring (like many other later-style alternators), six stator terminals on the outside edge of the positive rectifier, eight diode terminals, and three rivets (Figure 4). You will also find that the SRE frame on these units is very hard to remove. In fact, one of the more difficult things about working on 4G units is getting them apart. One reason for this is that the SRE frame has only three thru-bolts, so you don’t have anything directly across from the thru-bolts to get leverage on. Also, the SRE bearing has plastic tolerance rings. And finally, because the stator stays in the DE frame, you must unsolder the stator leads to separate the unit. Figure 1. Saddle-mount units with slotted mounting holes were the second version of the 4G to be introduced. In 1996 Ford introduced a unit with unique long- arm mounts (Figure 2) that is used on 1996 3.0L V6 Ford Taurus and Mercury Sable (WAI #1-1993-11FD). Also in 1996, Ford began using two side-mount versions of the 4G, one on Windstar with 3.8L engine (WAI #1-2012-21FD) and the other on Explorer with 5.0L V8 engine and F Series pickup with 4.6L V8 (WAI #1-2024-21FD) (Figure 3). See the chart on page 2 for complete details on all these units. WA Wetherill Associates, Inc.- 1101 Enterprise Drive – Figure 2. A version with long-arm mounts was introduced in 1996 on 3L V6 Taurus and Sable. Figure 3. A side-mount version was used on several 1996 models. SRE Frame Assembly When you look at the inside of the SRE frame on a 4G unit, you see the four negative diodes, four pos- itive diodes and the bottom side of the three rivets (Figure 5). To separate the positive rectifier from the SRE frame, unsolder the four negative diodes and drill just the heads of the three rivets. The three negative Royersford, PA 19468 + 800-877-3340 Care is taken to ensure the accuracy of information presented here, but Wetherill Associates, Inc., assumes no responsibility for possible errors. Copyright © 1996 Wetherill Associates, Inc. 5172 Technical Update 32 page 2 WAI Ref. No. OE No. Application Regulator See Figure 1 1-1904-11FD F50U-10300-FA 1995-96 Continental V8 4.6L 35-208 F5QU-10300-FB 1-1988-11FD F6LU-10300-CA 1996 Mark VIII V8 4.6L 35-210 F6ZU-10300-BB 1996 Crown Victoria V8 4.6L F6ZU-10300-BC & 1996 Mustang V8 4.6L See Figure 2 1-1993-11FD F6DU-10300-BB 1996 Taurus & Sable V6 3.0L 35-208 See Figure 3 1-2012-21FD F68U-10300-AD 1996 Windstar V6 3.8L 35-208 1-2024-21FD F77U-10300-AB 1996 Explorer V8 5.0L 35-210 F77U-10300-AC & F Series Pickup V8 4.6L diodes with white potting material are 50-amp and the one with black potting material is 25-amp (Figure 6). These units also use three positive 50-amp diodes and one positive 25-amp diode. Both of the 25-amp diodes in this unit have a small “dimple” on the bottom (Figures 5 & 7). The positive rectifier has a copper heat sink Figure 4. The 4G has a small slip ring, six stator termi- nals and eight diode terminals. Letters mark stator connections. molded into the plastic. For cooling, sections of this heat sink are cut and bent over rather than removed. The bent material acts like fins for better transfer of heat away from the rectifier (Figure 7). Ford made a change in the rectifier on later versions of this unit. The early-style rectifier had a metal tab for battery connection to the voltage regulator. However, since there was no connection on the voltage regulator for this tab, it really served no purpose, so Ford eliminated the tab in later versions. At the other end of the rectifier a tab is still used as a connection point between the stator and voltage regulator (Figures 8 & 12). Testing Rectifiers AG rectifers used different amp-rated diodes. When you use a diode tester to do a forward voltage-drop test, the reading will be slightly higher on lower amp-rated diodes. Different testers will give slightly different readings. The readings below were from the tester we used. Figure 5. Inside the 4G SRE frame you see four negative and four positive diodes and the bottom side of three rivets. Refer to Figure 4 for correct stator connections. To check the three positive output diodes, con- nect one test lead to the battery terminal. Then touch the other test lead in turn to the stator con- nections designated A, B and C in Figure 4. The readings should all be the same. With the tester we used, we got readings of .706 forward voltage drop. To check the positive diode at the “Y” con- nection (designated “D”’; see Figure 4), connect one test lead to the battery terminal and touch the other test lead to a stator connection designated Da, Db or Dc. You only need to test one of these connections, since they all connect to the same diode. Our reading for this test was .718.