FORD 3G Alternator

[MY1PATH]

Common NOTES;

• I know not, what vehicle this alternator comes on origainally. Just that it is a Ford 3rd Generation Alternator (Ford 3G) and that the tabs need to be in 120 or 180 degree configureations for this to work.
• 180 AMP was a rewind and suffers a HIGH Cut in, not enough juice @ idle uness you do some custom work(see updates @ bottom). Ford 3G altys come in 115 to 140 amp variations and many part stores offer 160 amp replacements which would be much more well suited because of the lower cut in.
• The regulator and brushes are on the outside and can be changed ON the Vehicle so the only time you need to take it off is if the bearings ever fail. Nothing else on these is prone to easy failure(unlike the nissan ones) so no more changing alternators when one fails. Just swap the reg and brushes.

 

I've had a few requests on this one so here it goes (finally).

After 3 or 4 altys in 20 years I finally got smart and made the 2nd to last one a 90-95 alty which puts out 70 amps instead of 60. All the previous Alty's faied because the VoltageRegulator(VR) was running full open too often in order to keep up with the electrical load, they would evenually all lock open so when there was not such a load there would be a voltage spike which results in overcharged batteries, blown bulbs etc. Then I got even smarter when somone here sold their 180 AMP R50 alternator. When I got it the VR had been smashed in shipping but there was a sticker on the side for Ohio Generator, I called them and I looked @ alternators online and Figured out that this was actually a Ford 3G alty. Ohio generator had simply re-wond it to 180 amps and made a pigtail that converts the Ford plug to a nissan plug. Knowing this anbody could take the standard 120 and 140 amp 3G and do the same... The wd21 alty has its mounts 180deg apart and the ford 3g that you want will have its tabs 120deg apart (if you can find 180 great) but the bottom tab will be 60deg too far counter-clockwise this would require a longer custom bracket and even then the Tab woul hit the steering box before you could tighten the belt. If you remove the 3 bolts that hold the case you can rotate the front half so the the top becomes bottom and now your 60deg clockwiese this reqires a shorter bracket so I cut mine about 2.5-3" shorter and drilled a new hole to bolt it to the block.

 

At this shorter position the head of the bolt for the tentioner would now contact the belt so I cut the bolt down and had it welded inside the tentioner tab which also got shaved down a little so that I have about 5/16 clearance to the belt and no sharp edges. (the angle of the picture makes it look like there is less clearance than there is)

Then I hooked up the wires + and ground to the case and the Ford->NISSAN pigtail for the battery light. If your going to make this connector you'll need the 2 plugs off the donor vehicle and a plug that will plug into the NISSAN battery light plug(unless your hard wireing that end).

The Wires colors may vary but locations should not and will go as follows;

Ford 3 prong plug

Prong 1(yellow/white) goes to Nissan battery light plug Heavy guage wire(white)

Prong 2(white) goes to Ford single prong on case (also white)

Prong 3(green/red) goes to Nissan battery light plug smaller guage wire(yellow/black)

 

Now before you go and do this, Keep reading...

I ran some power tests under various loads and this Ford alty Requires Very high RPM's to generate its peak output (180A) When I got it it had a 2" serpentine pulley on it (from the R50) and was prolly fine but at Idle with the 3" WD21 V-pulley it DID NOT PUT OUT ENOUGH POWER. But going down the road It can handle any power demand I throw at it.

It took a 2.5" (smallest v-pulley I could find) chevy pulley machined wide enough to fit the nissan V-belt and an increased Idle(900rpm) to keep up with lights, e-fan, small stereo & blower motor. I may even try to get a 2.3"(Limitations of wall thickness and groove depth will prvent me from going smaller) pulley machined for it. This may just be characteristic of an alty Re-wound so high. Now becuse of that last tidbit I do not reccomend this to anybody running v-belt accessories unless you wanna get a pulley macined or somehow have a larger crank pulley. But now that I have it done, I'm not going back. The Ford alty is completely rebuildabe with all basic hand tools and when I do my engine swap I'll prolly be serpentine in which case I will have no problem getting enough power out of it.

 

UPDATE;Oh yeh, and when I went down to the 2.5" pulley I was able to use the stock length v-belt.

UPDATE 6/17/2010; I recently had a 2" v-belt pulley machined It provodes enough power to run ALL accesories @ idle or lower but the belt slips allot under load & low RPM even when tightened to 1/2" the rated deflection.(belt keeps stretching @ this point) It just does not have enough wrap arround to make sufficent grip.

UPDATE 7/11/2010; I used a modified T-belt tensioner bolted to the upper tab to give the Belt a little more wrap arround. Slip only ocurs momentarily on startup when belt is cold. I will be adding another T-belt tensioner to the lower tab (when I get one) and this will give pretty close to 180* of belt contact with the 2" pulley for slip free interface that povides all the juice I need from idle up.

Edited July 11, 2010 by MY1PATH

[Tungsten]

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