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How to tell if you have a 70 amp system?


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Hello,

 

Midlife is going to be working on getting most of my wiring harnesses back in good shape. One of the things I need to do is to replace my short alternator harness.

 

Vendors show either a 70 amp or standard harness. Is there a simple way to tell which would be correct? The vert came factory with A/C and power top, no power windows. The current alternator is not factory original, it was replaced several years ago by a PO.

 

Any guidance would be appreciated.

 

Thanks,

Scott

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I don't have a 73 Electrical assembly Manual. The 72 manual I have states the 65 Amp alternator was installed on 351CJ vehicles with AC and Heated Back Lite, with or without gauges, if I'm reading the notes properly. Another reference book I have shows the following. 1973 8 cyl. with AC, 42 or 55 or 61 Amp alternator, with gauges takes harness number D3ZZ-14305-E. I have no way to verify the accuracy of the information. It may be a place to start. Figuring this out on my 72 was a nightmare until I figured out due to production changes and build date, my 72 actually required a D3ZZ harness. Please let us know what you find out. Chuck

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I don't have a 73 Electrical assembly Manual. The 72 manual I have states the 65 Amp alternator was installed on 351CJ vehicles with AC and Heated Back Lite, with or without gauges, if I'm reading the notes properly. Another reference book I have shows the following. 1973 8 cyl. with AC, 42 or 55 or 61 Amp alternator, with gauges takes harness number D3ZZ-14305-E. I have no way to verify the accuracy of the information. It may be a place to start. Figuring this out on my 72 was a nightmare until I figured out due to production changes and build date, my 72 actually required a D3ZZ harness. Please let us know what you find out. Chuck

 

Thanks for the starting point Chuck. I do have the 73 Electrical shop manual, maybe that's a place that might guide me. The PO added the gauges in the center but I think the ammeter ties somehow into the alternator wiring harness since there were splices all over the place. Seriously I'll bet my underdash and other harnesses had at least 25-30 splices!

 

Argh!

 

Scott

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I just replaced my alternator harness and I learned that I have a 70 AMP system. My vert came with factory air, power top and power windows. I do not have the gauges in the center of the dash. I was lucky since I still have the original alternator.

 

Mike

57_23_07_10_12_47_19.jpeg

 

White 1973 (351C stroked to 408, 4V, FMX) convertible with blue deluxe interior AC and power windows.

 

Mike

Irwin Pa (MCA # 52193)

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I don't have a 73 Electrical assembly Manual. The 72 manual I have states the 65 Amp alternator was installed on 351CJ vehicles with AC and Heated Back Lite, with or without gauges, if I'm reading the notes properly. Another reference book I have shows the following. 1973 8 cyl. with AC, 42 or 55 or 61 Amp alternator, with gauges takes harness number D3ZZ-14305-E. I have no way to verify the accuracy of the information. It may be a place to start. Figuring this out on my 72 was a nightmare until I figured out due to production changes and build date, my 72 actually required a D3ZZ harness. Please let us know what you find out. Chuck

 

Thanks for the starting point Chuck. I do have the 73 Electrical shop manual, maybe that's a place that might guide me. The PO added the gauges in the center but I think the ammeter ties somehow into the alternator wiring harness since there were splices all over the place. Seriously I'll bet my underdash and other harnesses had at least 25-30 splices!

 

Argh!

 

Scott

Ammeter joins into the headlight harness only.

Let me check your shorts!

http://midlifeharness.com

cactus.jpg.92e5d9d8700abc0ed60c8ccb3426248e.jpg

 

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My 73 Mach 1 has it's original alternator (53,000 miles) and it is a 70 amp model. My car has the rear window defrost and power windows which are high current draw devices which is why it has the higher output alternator. My other 73 Mach 1 has the 55 amp alternator and it does not have those options. I can get a photo of my 70 amp alternator/harness if that would help.

Steve

73 Mach 1 Blue Glow/Argent Q Code C6 Auto

73 Mach 1 Blue Glow/Argent Q Code 4 Speed

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Vertstang and Steve73, If you can post picture it would be very helpful future reference. It is amazing how under documented these (71-73) Mustangs are. Thanks, Chuck

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Here are some photos of my 70 amp alternator and harness:

2n1zxow.jpg

iqwolx.jpg

2lseczq.jpg

Steve

73 Mach 1 Blue Glow/Argent Q Code C6 Auto

73 Mach 1 Blue Glow/Argent Q Code 4 Speed

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What part numbers are on that Alt. ? I have never seen a side post alt on a 71-3. Always see connections on the back.

Is it a late 73 ?

Don

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Guest BigPinoyHunk

it doesn't cost much to upgrade to a 1 wire alternator and it'll clean up some clutter under the hood elminating an entire harness and replacing it with only 1 8 guage wire from alternator to the terminal block or hot pos on the starter relay.

 

i got a tough stuff 1 wire for only like 80 dollars and its a life time warranty item.

 

something to think about!

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The picture matches the drawing of the 65 amp alternator shown in the electrical assembly manual. It may mean the D2ZB-14305-EA (without gauges) OR D2ZB-14305-DA (with gauges) harness will work. Call these guys and ask them to help you sort out what you need and they may have it or point you to a source. Chuck

 

http://www.greensalescompany.com/default.asp

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What part numbers are on that Alt. ? I have never seen a side post alt on a 71-3. Always see connections on the back.

Is it a late 73 ?

Don

 

Don,

 

Here is a photo of the alternator part number. This 70 amp side terminal alternator is covered in the Electrical section (page 31-12-01) of the 1973 Ford Shop manual. And yes, the car is a very late 1973 model (June 29, 1973).

2dvrju9.jpg

Steve

73 Mach 1 Blue Glow/Argent Q Code C6 Auto

73 Mach 1 Blue Glow/Argent Q Code 4 Speed

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What part numbers are on that Alt. ? I have never seen a side post alt on a 71-3. Always see connections on the back.

Is it a late 73 ?

Don

 

Don,

 

Here is a photo of the alternator part number. This 70 amp side terminal alternator is covered in the Electrical section (page 31-12-01) of the 1973 Ford Shop manual. And yes, the car is a very late 1973 model (June 29, 1973).

2dvrju9.jpg

 

Thanks for the pic / info

80 + 71-3 parts cars and still finding out new stuff LOL

Never had a 73 that late - Now I'm wondering what else is changed

Don

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oh towards the end of the 73 model year all kinds of wacky things made on onto cars that was not documented. its like they just ran out of parts and tossed on whatever they got their hands on.

 

oh D30F10300AA also decodes to a 73 ford Fairlane, its possible that alternator and harness was replaced from a fairlane during a repair.

 

 

But, If your car was built with AC the heavy duty alternator was included. if you had a heavy optioned car you got the Heavy duty alternator as well.

 

 

now if i remember wasn't OEM either a 38 amp or 55 amp setup, i don't think they had a factory 70 amp alternator.

 

I remember researching this like 5 years ago. because i had issues with a replacement voltage regulator and garbage alternator. I remember distinctly going for OEM and there was only a 55 amp alternator available. the reproduction voltage regulator was a problem because at the time they only had the standard regulator for reproduction. This caused my lights to flicker like crazy and not charge the battery well. then they came out with the Reproduction Heavy duty voltage regulator and that solved my issues.

 

but i still never saw a factory 70 amp system mentioned.

i know you could get 70 to 240 amp alternators but then you go aftermarket solid state voltage regulators.

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oh towards the end of the 73 model year all kinds of wacky things made on onto cars that was not documented. its like they just ran out of parts and tossed on whatever they got their hands on.

 

oh D30F10300AA also decodes to a 73 ford Fairlane, its possible that alternator and harness was replaced from a fairlane during a repair.

 

 

But, If your car was built with AC the heavy duty alternator was included. if you had a heavy optioned car you got the Heavy duty alternator as well.

 

 

now if i remember wasn't OEM either a 38 amp or 55 amp setup, i don't think they had a factory 70 amp alternator.

 

I remember researching this like 5 years ago. because i had issues with a replacement voltage regulator and garbage alternator. I remember distinctly going for OEM and there was only a 55 amp alternator available. the reproduction voltage regulator was a problem because at the time they only had the standard regulator for reproduction. This caused my lights to flicker like crazy and not charge the battery well. then they came out with the Reproduction Heavy duty voltage regulator and that solved my issues.

 

but i still never saw a factory 70 amp system mentioned.

i know you could get 70 to 240 amp alternators but then you go aftermarket solid state voltage regulators.

 

Like I mentioned in an earlier post in this thread, my Mach 1 came with rear window defrost and power windows - both of which are high current devices. The alternator in my Mustang is the original 70 amp unit that it left the factory with because of the options it has. As for D3OF 10300 AA decoding to a Fairlane, the third character in the Ford part number is the Model Design character. Yes, "O" does equate to a Fairlane, but "O" is also a generic model design character (same with A and S). Just because the third character in the part number is an "O" in this case does not mean it came from a Fairlane or was originally designed for a Fairlane. The generic model design characters can apply to all models. There are plenty of parts on the Mustang that do not have a Z as the third character. If the third character is a Z though, it was exclusive to the Mustang because Z is not a generic model design character.

 

You are correct - the Mustangs did come with a 55 amp alternator. However, the 70 amp alternator typically came with Mustangs that had rear window defrost and and some other high current options (like AC or power windows). Surely there are more Mustangs on this forum than mine with a 70 amp alternator.

Steve

73 Mach 1 Blue Glow/Argent Q Code C6 Auto

73 Mach 1 Blue Glow/Argent Q Code 4 Speed

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cool, learn new stuff all the time :D

 

Hey you should see the weird stuff on early 71's

They were making it up as the built them

 

There were 3 different types of seat side rail covers.

 

Ever wonder what the extra holes in your front valance and the bottom core support were for !!!!

 

Different beltline weather strips on the doors

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same for 72. my 72 had all kinds of weirdness a mix of 71 and 73 parts. even more now since i grab what i could to get it going again :D

 

its a 1 of 1 now. lol

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Well !!!!

Now that I think about it, maybe B.T. needs this as a VIP question.

 

So, it's like that is it. I read what "The Plain Dealer" said about you but I didn't believe it, until now. I dub thee Sir Don the Bogart.:P :P

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cool, learn new stuff all the time :D

 

Hey you should see the weird stuff on early 71's

They were making it up as the built them

 

There were 3 different types of seat side rail covers.

 

Ever wonder what the extra holes in your front valance and the bottom core support were for !!!!

 

Different beltline weather strips on the doors

Tell me about it! I have a 71-73 underdash harness from some Ford, and it doesn't match any of the documentation for any Ford car, truck, or van from 68 to 74. The closest match is a 72 Torino, but even then, it's not exact. I also pulled a dash cluster connector from a 74 F-100 and that documentation said it didn't have that connector.

 

I think Ford started smoking the evil weed circa 71 and it is reflected in their work and documentation. Either that, or everyone was out watching bras being burned.:P

Let me check your shorts!

http://midlifeharness.com

cactus.jpg.92e5d9d8700abc0ed60c8ccb3426248e.jpg

 

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No, I never did but now I do. Come on Don share the wealth. What were the holes for?

Simple...To let water drain out so it didn't sit puddled in the valance

LOVE OF BEAUTY IS TASTE..THE CREATION OF BEAUTY IS ART

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