How Many Gs in Ford? By Juan C. Grube Ford has used many different alter- nators over the —; years, from exter- = i 7 nally regulated to in- A ternally regulated. y Even with this large variety of types and styles, each was operationally the same. That is, one 3G operated the same as the next—same with the 4G series. Granted, there were many different part numbers, but these were either output, mounting, or load response time differences. If you saw one, you had seen them all. The differ- ent part numbers hooked up and tested the same. The new 6G series has changed all of that. There are now three differ- ent methods of operation. They may all appear to be the same, but they hook up and test differently. The first 6G, I’ll call it the “stan- dard” version, was used on the Crown Victoria, Mustang and pickup-based vehicles. This version was operation- ally the same as the 4G, with regulator terminals “T”’ (L) – “” (BLANK) – “A” (SENSE). To operate this alternator your test lead needed only to connect a“no charge” indicator light to “T’ (L) and system positive to the “A” (SENSE) terminal. The second version appeared on the Contour, Cougar and Mystique. Let’s call this the “GLI” version. This alternator has regulator terminals “TI” (L) – “GLI” (FR) – “A” (SENSE). It oper- ates much like the “standard” version except the middle terminal is now a (FR) field rate terminal called “GLI,” Generator Load Input by Ford. This terminal is where the vehicle computer determines how hard the alternator is working and, if necessary, adjusts the engine idle speed. MARCH/APRIL, 2000 To operate the “GLI” alternator your test lead needs to connect a “no charge” indicator light to “T’ (L) and system positive to the “A” (SENSE) terminal along with an auxiliary volt- meter to monitor the (FR) terminal voltage. The voltage at the “GLI” (FR) terminal is the field voltage which will change with the amperage output of the alternator. The auxiliary voltmeter reading will range from approximately 10.5 volts at low amperage output to 1.5 volts at full amperage output. The exact reading is not important as it changes with load and rpm. What is important is that it does change with load. The third version 6G alternator, Ford calls it the “PCM” alternator, is used on the 1999 and 2000 Windstar, 2000 Lincoln LS and the new Focus. The European Ford Focus uses a Magneti-Marelli alternator that is op- erationally the same. The “PCM” ver- sion has regular terminals “GEN- MON” (FR) – “GENCOM” (SIG) – “A” (SENSE). The operation of this (P3) POO a ee eee ee eae eee i} 1 . 1 ee 1 | 2) — qc Ok i () i (F2) — et o — i REGULATOR > | REGULATOR “V2 —_— | “FULL FIELD il ine | | “FULL FIELD s 4 ; BY-PASS” (G a ! * * ! -PASS” i : | By-Pass (©) Vet maint NO CHARGE’ | GROUNDING i oi | SRRONT. A | 7 INDICATOR LIGHT a an oe | ; : p42) a | 3 ! eo is en ner Nc | ee ee Qt— ANN : INDICATOR LIGHT oe pele ee “)! | : 3} SWITCH (PI ) a y ; ‘7 eel if _ = a “GLI” rs | – q | ° oa KAA Wa ! 7 ‘ IGNITION ERMC AAA fasregr +}. Topom ) DUAL’YY | | |G) (N) @) <>) DUAL”Y* Tt the) dite STATOR | eh) MATOS i SS i i 1 | positwe | tg 7) Jq_-4 NEGATIVE | | POSITIVE Fie NEGATIVE SS | | RECTIFIER ri¢ ol acu KOs ND | RECTIFIER i i¢-+hectiFicr ae i wD) a ae i i or i i} Oo sai 1 1 2 S See | | ecee Ce Cy aa | >> X | : | | ‘ i} i i} i} al iq Page 1 of 1