Alternator Part No. & 1 wire options

[seej369]

Good Evening Everyone,

I've got the perkins diesel from 1983. I believe the alternator is a 1G large case, but I cannot find positive confirmation on a part no. the mounting style is 12 and 6 with a distance of 8.3" between the bolts. Most alternators that claim to fit are 6.8" and the two I have ordered and sent back are too small as well. The vacuum pump tensions off of the alternator and I don't thing an adapter bracket would work very well. Ideally I would install a 1 wire alt, but anything is helpful at this point as I had to sawzall the old one out of its rusty grip.

 

[SenorNoob]

1 wire was always a GM thing wasn't it? Not saying it's not possible to swap.

That's a pretty rare engine. Someone might have suggestions if they could see it. Can you upload a picture or 2?

 

[seej369]

Good Evening Everyone,

I've got the perkins diesel from 1983. I believe the alternator is a 1G large case, but I cannot find positive confirmation on a part no. the mounting style is 12 and 6 with a distance of 8.3" between the bolts. Most alternators that claim to fit are 6.8" and the two I have ordered and sent back are too small as well. The vacuum pump tensions off of the alternator and I don't thing an adapter bracket would work very well. Ideally I would install a 1 wire alt, but anything is helpful at this point as I had to sawzall the old one out of its rusty grip.

to answer my own thread. I am still not sure which alternator came stock, but I was able to fit a ‘94 ford Taurus 3.8 alternator into the mounting. A few pigtail mods, some 4 gauge, a circuit breaker and a switched ignition tie in at fuse #7 wrapped up my 3g upgrade. Fell free to ask for details if you want to try as well.

 

[4x4prepper]

Thank you for posting what worked. I read the topic because I see (2) diesel Rangers on CL and I am seriously thinking about picking them up. The only thing that is really holding me back is my tow vehicle is not ready. So, the topic was of interest.

 

[84tony]

If you still looking for a Ford 1 wire alternator, try this place. Ford 3G high output alternator high amp replacemen (qualitypowerauto.com)

 

[RonD]

Its not hard to convert to 3G alternators, or 1 wire

3G just have internal voltage regulator and 4 wires
B+ is the larger wire, alternator output, hooked to battery positive with a Fuse or Fusible link, same on all alternators

3 wires for voltage regulator
"A" wire is also hooked to battery positive full time, yellow wire on Fords, uses 15amp inline fuse or fusible link, can just be hooked to B+ with inline fuse so 1 less wire
"S" is a short jumper wire, goes from voltage regulator to Stator hookup on back of alternator, white wire on Fords

"I" is key on power, it prevents alternator from draining power from the battery when engine/key is off
So its the on/off switch for alternator
Also used as "Battery Light" in most vehicles
When you turn on the key the battery light comes on because it gets 12v from ignition switch and is "grounded" by Voltage regulator because alternator voltage is at 0volts with engine off
But that 12v is passing thru the battery light bulb and to the Voltage Regulator and that voltage is used as Startup Voltage so alternator can start producing its own voltage
When engine starts Battery light goes OFF because BOTH terminals of the bulb have the same 12volts now
This is usually a green wire on Fords

The Battery Light bulb is not needed, just the Key on 12v is needed to prevent battery drain, but handy to have


One wire alternators have all the above, internal regulator with all the wiring but its all internal
Just has the one larger wire at B+ hooked to battery positive via a fuse
"A" gets 12v from that connection internally
"S" jumper is internal

"I" uses B+ connection, BUT thru an RPM/centrifugal switch, so alternator is OFF until it reaches a minimum RPM and the switch connects "I" to B+
You have to watch the minimum RPM rating on these, and with a Diesel its even more important since they tend to be low RPM engines
You can adjust the pulley size to increase alternator RPM to crank pulley RPM
i.e. Google: Pulley RPM calculator

You want alternator RPM at minimum 1,800-2,000 at idle, they are fine up to 8,000rpm
Measure your crank pulley size and go from there