Alternator question
- Thread starter polarus
- Start date
1972 is generally considered the first year, but I've read of a few 1971 cars having them, but I wouldn't say that's reliable info.
The only advantage with them is the diode bridge is easier to replace, but I've also read (and experienced) more diode failures in them. Again, not reliable info.
That question might be answered in the Chrysler MasterTech videos on "What's New" For 19__". Those videos are now at www.mymopar.com and have been on the Imperial Club website for years.
As alternators cool from the back, rather than from the front, cooling the guts of the operation was probably the reason for the change, I suspect. As cars were getting more electrical options, generally, more cooling was probably needed.
Just some thoughts,
CBODY67
As alternators cool from the back, rather than from the front, cooling the guts of the operation was probably the reason for the change, I suspect. As cars were getting more electrical options, generally, more cooling was probably needed.
Just some thoughts,
CBODY67
Well . . . a quick check of the MasterTech videos revealed nothing. I started in 1970 ("Browse by Model Year" as the "Browse by Subject" didn't work) and discovered THREE types of alternators (and their respective voltage regulators!) for 1970, in the voltage regulator diagnosis video. No mention of other alternator-related videos until the 1975 model year 100Amp alternator video. So much for that bright idea!
GOLDMYN
Senior Member
I've got a 71 Newport
Thread -- www.ForABodiesOnly.com June 11, 2015 "Explain Square Back Alternators"
Quite informative and explains the differences between the two styles and types. Plus how to use the newer Chry and Denso alternators on older vehicles.
Extending the items I found in the 1970 MasterTech videos that there are MORE minor differences in Chrysler charging systems, over they years of the 1970s than ever expected.
In this last respect, I recall the late Daniel Stern mentioning that the alternator on his late-1990s Dodge pickup truck was controlled by "the computer". He ended up finding a resistor to plug into the wiring harness so the computer would think it was hooked up to the alternator, then wired the alternator as his old Dodge Dart (later 1960s) with an external voltage regulator AND everybody lived happily ever-after. As the only part of the computer board which had failed was the one section related to alternator charging, so he took that function "external" and things worked well for him. PLUS costing much less than the price of the new computer.
Enjoy!
CBODY67
Quite informative and explains the differences between the two styles and types. Plus how to use the newer Chry and Denso alternators on older vehicles.
Extending the items I found in the 1970 MasterTech videos that there are MORE minor differences in Chrysler charging systems, over they years of the 1970s than ever expected.
In this last respect, I recall the late Daniel Stern mentioning that the alternator on his late-1990s Dodge pickup truck was controlled by "the computer". He ended up finding a resistor to plug into the wiring harness so the computer would think it was hooked up to the alternator, then wired the alternator as his old Dodge Dart (later 1960s) with an external voltage regulator AND everybody lived happily ever-after. As the only part of the computer board which had failed was the one section related to alternator charging, so he took that function "external" and things worked well for him. PLUS costing much less than the price of the new computer.
Enjoy!
CBODY67
Last edited:
Great input guys, thanks. When it comes to Mopar nothing is cut & dry. I thought 72 was the first year for the square back but a friend of mine thinks it was 71, (agree to disagree.) I won't even get in to Police package Mopars, Chrysler alternator? Leece/Nevelle? Motorola? All were available in the early 70's squad cars, all required their own brackets.
Square back not in the 1971 FSM, but is in the 1973 FSM. Which until I can get into the 1971 and 1972 Chrysler parts books, I am inclined more toward 1972 model year than 1971.
NOW, this is "talking" model years, not calendar years. It IS possible that some late-production 1971 cars could have had the 1972 electrical items, as long as they all went into the same place as the 1971 items. More possible for first-of-the-model year production, typically, during the "transition period" of sorts.
CBODY67
NOW, this is "talking" model years, not calendar years. It IS possible that some late-production 1971 cars could have had the 1972 electrical items, as long as they all went into the same place as the 1971 items. More possible for first-of-the-model year production, typically, during the "transition period" of sorts.
CBODY67
It sometimes comes down to running changes during the year. Most of us have had one car or another, particularly newer cars, that you need to know if it was made by a certain date in order to buy parts.
In this case, the alternators are interchangeable in function and fit, so a running change on the line is entirely possible. The square back was just a change in the rear half of the housing too, so it wasn't a complete redesign. IMHO, the square back was probably cheaper to build without the pressed in diodes that needed to be individually soldered, so again, a running change to save money without any functionality change.
Complicating figuring this out is almost all of the surviving cars that no longer have the original alternators and since they interchange operationally, any alternator was obtained and bolted in. The true test would be to dig up a bunch of alternators and look at date codes, although even that might not tell the whole tale as a September build 1972 car might have an alternator that was built in July... and that late build 1971 car could have that July dated alternator too.
When it really comes down to it, I think the safe bet is if you're restoring a 1971 car, go with a round back and a 1972 car will get a square back.
Would that have been back on the Mopar Mailing List of the 1990's ? I remember exchanging messages with him at the time, we both had a slant-6 car (my '65 Polara and his Dart I believe). I did meet up with him once on a business trip to southern california in the late 90's (Anaheim unless I'm mistaken). Didn't know he passed.
Seems like I first learned of Mr. Stern in the late 1990s (as I was using WebTV back then) from the AllPar forums or the old Usenet Chrysler-oriented BBS? I do not believe it was MML as at that time, MML was more like people conversing back and forth rather than e-mailing. Not what I was expecting, from all I had heard about it back then.
I might have mis-spoke about his passing, but I saw something about that in another forum, possibly an AACA forum, a few days ago. When I went to his website, all looked well and one of the pages was last updated in Sept 2023, so he must still be with us, I suspect.
The Daniel Stern Lighting website has a vast amount of information. Lots of newer content from the last time I looked, about 15 years or so ago. Need to get "caught up".
Take care,
CBODY67
I might have mis-spoke about his passing, but I saw something about that in another forum, possibly an AACA forum, a few days ago. When I went to his website, all looked well and one of the pages was last updated in Sept 2023, so he must still be with us, I suspect.
The Daniel Stern Lighting website has a vast amount of information. Lots of newer content from the last time I looked, about 15 years or so ago. Need to get "caught up".
Take care,
CBODY67
Dan posted Friday on FABO and Saturday on the Slant Six forum.
So, I would assume the reports of his death are exaggerated.
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