Ron Francis / Denso alternator hookup

[R3dplanet]

Hey peeps,

I'm having a hell of time with the Ron Francis XP-777 wiring harness I'm attempting to install into my '65 Barracuda. I have a long list of complaints about this harness but right this moment I'm just trying to install the alternator. For years I've happily used the 3-wire Denso alternator used in late 80s Toyotas without any trouble at all.

The RF instructions reference only a 1-wire style. And the wire color doesn't match the Chrysler wiring diagrams for '65. The whole thing is an afterthought.

What I have so far is the heavy 8awg wire that runs from the BAT post on the alternator through a 70amp maxi-fuse and then on to the post on the starter relay, which then runs to the starter and battery. Great.

But where do the other two wires go? I think one of them would go the fuse panel and the other would go .. to the battery? The instructions really only mention GM wiring. They also caution not to compare the RF diagrams to the factory diagrams.

Before anyone asks I have asked them for help in the past and all they do is copy/paste the instructions again without any further explanation or help.

For reference, this is what the alternator looks like:

 

[mopowers]

The charging wire to the battery/starter relay goes to the large post on the alternator. The other three terminals are as labeled in the diagram below:

 

[67Dart273]

I'm pretty sure Ron Fancis harnesses include an "exciter" wire to the engine bay. Look for that which goes to the IG terminal in the diagram

Above, you would run a separate wire direct to battery from the alternator "S" terminal. I would inline fuse this. It is very low almost no current, the "sense" wire.

 

[R3dplanet]

The charging wire to the battery/starter relay goes to the large post on the alternator. The other three terminals are as labeled in the diagram below:

View attachment 1715735476

Thank you for the diagram. Sadly, I don't understand the terminology. "12v reference" means what / where? Does "12v ignition switched source" mean 12v supplied to the fuse box or 12v supplied from elsewhere?

 

[R3dplanet]

I'm pretty sure Ron Fancis harnesses include an "exciter" wire to the engine bay. Look for that which goes to the IG terminal in the diagram

Above, you would run a separate wire direct to battery from the alternator "S" terminal. I would inline fuse this. It is very low almost no current, the "sense" wire.

Okay. Running the sense wire to the battery is easy enough. Thank you for that. I can easily put a fuse in there.

 

[R3dplanet]

Thank you fellas. I finally understand.

 

[autoxcuda]

I followed that 3-wire diagram mopowers posted. Been running it for 10 years with stock 50 year old wiring harness.

... not bad for a junkyard alternator. I bought it 20 years ago just to see if it would fit. Pretty good alternator seems.

 

[pishta]

Those alternators are great! Small, cheap and powerful enough for the older cars. I have one from a Suzuki Swift thats low mounted, 65 amps. about 2X what the original 35A was worth. Only bad thing is they all seem to not be V-belt.

 

[autoxcuda]

Those alternators are great! Small, cheap and powerful enough for the older cars. I have one from a Suzuki Swift thats low mounted, 65 amps. about 2X what the original 35A was worth. Only bad thing is they all seem to not be V-belt.

I think mine came off a 4 door car. Like a Geo or Nova variant. It had a V-groove pulley.

It’s 2 3/4” diameter OD.
My water pump pulley is 6 1/2”
My pulley centers are 9 1/2” apart.

On heavy acceleration, it squeals. Pulley alignment is spot on. Wonder if the ratio isn’t right

 

[famous bob]

Hey peeps,

I'm having a hell of time with the Ron Francis XP-777 wiring harness I'm attempting to install into my '65 Barracuda. I have a long list of complaints about this harness but right this moment I'm just trying to install the alternator. For years I've happily used the 3-wire Denso alternator used in late 80s Toyotas without any trouble at all.

The RF instructions reference only a 1-wire style. And the wire color doesn't match the Chrysler wiring diagrams for '65. The whole thing is an afterthought.

What I have so far is the heavy 8awg wire that runs from the BAT post on the alternator through a 70amp maxi-fuse and then on to the post on the starter relay, which then runs to the starter and battery. Great.

But where do the other two wires go? I think one of them would go the fuse panel and the other would go .. to the battery? The instructions really only mention GM wiring. They also caution not to compare the RF diagrams to the factory diagrams.

Before anyone asks I have asked them for help in the past and all they do is copy/paste the instructions again without any further explanation or help.

For reference, this is what the alternator looks like:

View attachment 1715735462

Why not put a 1 wire alt. on it ?