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Discussion Starter · #1 ·
Looking into doing the 3g alternator conversion on my 65 Galaxie. I found info on doing the conversion on a mustang, but VERY little to none for the Galaxie. Has anybody done this to their Galaxie? If so, whats a good donor alternator? 93 ford Taurus? Will this conversion harness work?
Ford Mustang 3G Alternator Conversion Harness Connector | eBay
Heading to the junk yard in the morning and any info would be grateful.
Thanks.....
 

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There have been several discussions about 3G alternators in Galaxies on this site. Please do a search for wiring info, what old wiring you can delete, which 3G version to use (and why), pulley versions, bracket and radiator hose considerations, etc.

If you have issues searching before you leave, I would just use the connectors that are already attached to the 3G at the wreckers. Use a 3G from a '94+ Thunderbird/Cougar with the 3.8L V6, or '94+ Mustang with V6 or 5.0 V8 as they fit most brackets without mods while clearing lower hoses better than the Taurus version (you didn't say what engine you have). Grab a the appropriate pulley (1 or 2 V-belt) pulley off of any earlier Ford to replace the serpentine pulley on the 3G. Do not try to swap it at the 'yard without the right tools or you'll damage the alternator internals. Read more when you get back. Have fun.

David
 

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At the bottom of this thread page there are a couple of 3G links, under "similar items."
 

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Discussion Starter · #4 ·
Thanks for the replies. Picked up a alternator off a 94 Cougar this morning. Found a pic on how to wire up the plug. Removed the serpentine pulley. Im guessing I can use the pulley off my factory alternator?? Sorry for not stating what engine I have, its a 390.
Thanks again for the help.......
 

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... Removed the serpentine pulley. Im guessing I can use the pulley off my factory alternator??
Yes. I have found original pulleys to sometimes rub the face of the 3G. Either source a new pulley (parts stores carry them - all the same for Ford and GM) or you can try a plain hardware store 5/8" fender washer to space it out. At least that has worked for me before, and is still going strong. Note you need to either use a through-bolt and nut for the adjuster bracket, or I install a threaded insert in the 3G's ear for a standard 3/8" adjuster bolt to make adjusting easier.

David
 

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Discussion Starter · #6 ·
Can the alternator belt still be used or is a longer belt needed to complete the install?
Thanks.......
 

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Yes - if using the small-ear 3G (which the '94 Cougar has) and mounted as the original was - the original belt will work.
:tup:
David
 

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Discussion Starter · #8 · (Edited)
After grinding the back of the alternator a bit (Very little) I was able to get the alternator past the block/head and mount up using the stock belt, Do I use any of the old wiring that came off the OEM alternator? Im hoping that one of the wires will have voltage when ignition is on. Will check tomorrow. There is a threaded hole I was going to use to ground the alternator as shown in the picture below, but the hole ends up right up against the block once mounted. Can I run a wire from one of the mounting points to use as ground?
 

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OK, I took a look at the 1965 Galaxie wiring diagram. The drawing you posted is almost good, but a couple suggested changes. First, you don't need the ground wire, as it grounds through the case and mount. Second, the "green" wire in your drawing is actually green/red - does not go to the ignition - but simply goes to your old GRN/RED that is at your old regulator. This wiring allows you to keep all functions, including your charging indicator. :D Once it's all connected and tested for full function, you can remove the wiring indicated below, and the old regulator also. Be sure to check the remaining BLK/YEL wire for good condition from the firewall, and make a good connection at the alternator BAT stud, as it is the primary power supply for your fusebox and other important stuff. ;)

David

Be sure to verify your wiring matches the copied original diagram below before making changes:
 

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There is a threaded hole I was going to use to ground the alternator as shown in the picture below
No need to ground separately as the unit is grounded thru the whole case that is grounded when mounted. (less wires, less confusion)
 

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You always externally ground the ALT.

The mounting ground may not provide proper grounding @ all times. That is why they put a separate ground lead on the harness. It is cheap insurance.
 

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You always externally ground the ALT.

The mounting ground may not provide proper grounding @ all times. That is why they put a separate ground lead on the harness. It is cheap insurance.

Ah ok..... :tup:
 

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You always externally ground the ALT.

The mounting ground may not provide proper grounding @ all times. That is why they put a separate ground lead on the harness. It is cheap insurance.
Ford did not ground them externally. None of the 3G factory harnesses I have dealt with have had external grounding. The same is true for 4G and 6G as well, and even the 1965 Galaxie did not have separate case grounding either. All have grounded through the case to the head or block and/or bracket. On a separate note - there are always two or more individual ground straps from the engine and transmission to the chassis to tie all grounding together.

While it wouldn't hurt to add one, the OP has clearance issues using that location, and using case ground is apparently sufficient for Ford. If he is intent on adding one, then a case assembly bolt could be used.

David
 

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Ford did not ground them externally.

None of the 3G factory harnesses I have dealt with have had external grounding. The same is true for 4G and 6G as well, and

even the 1965 Galaxie did not have separate case grounding either.

All have grounded through the case to the head or block and/or bracket.

On a separate note - there are always two or more individual ground straps from the engine and transmission to the chassis to tie all grounding together.

While it wouldn't hurt to add one, the OP has clearance issues using that location, and using case ground is apparently sufficient for Ford. If he is intent on adding one, then a case assembly bolt could be used.

David
:confused:

...crap...

Should I report this to ENGINEERING and PUBLICATIONS DIVISIONS to correct this or just let it go?
 

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Your pics don't show a case ground - you are misinterpreting it. The early regulators used a direct connection for grounding the other end of the stator coils (which are also case grounded) to ensure a good reference connection to the remote regulator - that's what you're seeing in the pics - not a case ground as you suggest adding. As the regulator is internal to the 3G, the equivalent connection is also internal.

Even with the early 1G style, the main ground is still through the case ears and to the block without an additional ground wire. Not surprising, as adding a wire to the case to go to a bolt on the block, when the case is already directly grounded, being tight under two bolts - is a bit overkill. Like I said, it wouldn't hurt anything, but... Additionally, if the added ground was to actually ground the alternator output, then the wire should be as heavy as the BAT cable. This reinforces the purpose of the small wire in your posted diagram, as it would burn-up in a flash if it were actually grounding the alternator output.

Again, rather than friendly discussion, you snipe with wrong info in a sarcastic and unfriendly manner, and it continues to not be appreciated. You are free to contact Ford Engineering to have them explain your error; however, I hope my explanation helps sufficiently to improve your understanding.

David
 

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Discussion Starter · #17 · (Edited)
Thanks for the help guys...... Did a quick install just to make sure everything works and was getting 14+ volts at idle. Just to clarify, when I removed the alternator from the 94 Cougar, there was no ground wire attached to the alternator. There was no stud for a ground wire. The threaded hole on the back had a bracket attached to it. I was going to attach the ground wire at that point, but I noticed there was not enough room to get a bolt back there once the alternator was installed. I’m assuming the alternator was grounded through the case at the mounting points of the alternator bracket.

While checking out the wires by the factory regulator, there is a small cylinder looking part with 1 black wire coming out of it. What is that for? The wire broke when I bumped it and was not sure if I still need that part or not after installing the 3g alternator..
Thanks……
 

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While checking out the wires by the factory regulator, there is a small cylinder looking part with 1 black wire coming out of it. What is that for? The wire broke when I bumped it and was not sure if I still need that part or not after installing the 3g alternator..
Thanks……
That's the alternator condenser. It's a capacitor that suppresses alternator noise. You should not need it now, but if you get radio noise (alternator whine) you can add it back in. Under $10 at the local store.

David
 
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