Alternator Question?

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Crazy4408pac

Crazy4408pac

N. Michigan
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Installing a new alternator on my Dart. I don't remember the ground terminal, on the old one. Is there something that goes to that? (See Pic.)
Also, good or bad idea, to put a lock washer on the adjustment bolt?
Thanks for any help.

altntr..jpg2.jpg
 
Auxiliary ground, so your choice to use it or not but it does create a nice ground for the alternator to block.
I personally wouldn't use it just because it's another wire under the hood for something that it already does through the brackets.
Some swear by grounding the alternator as well, even with the brackets ground.
 
Yes on the washer, I have to dig up the wiring diagram for the wires to the field terminals.
 
I think you'll find that upper spade terminal is also a ground. It's not like the other ( a brush holder ).
So... closed field. Green wire from regulator to the field terminal ( brush holder ) and ground(s).
If your harness has a blue and a green wire to alternator, that is isolated field system. You would need a different alternator with 2 brush holders.
A split lock washer would fail in the adjust slot without a flat washer.
 
That alternator is one from the 80s. The part number is probably 4091424 judging by the fact the housing has thicker fins than the older ones and a ground terminal. The upper spade terminal is not grounded, it is an isolated field alternator. Look closely and you can see the black insulating washers under the screw heads. Chrysler added that ground location around 1978, but they never used it until around 1983. I've never heard any reason why.
 
I can think of one reason for that ground screw. The guy at a part store who will mount it on a tester to spin it up will have a ground wire that needs to be put somewhere. A clearly marked ground stud removes confusion, keeps the clip off of fins and away from the inside components.
Maybe the factories engineers finally determined that relying on painted brackets and hardware for a chassis ground path wasn't the best plan/could be improved. Took long enough huh ? LOL
Whether there are 2 brush holders there or not, I'll back away, hide and watch. We don't know more than "Dart" about this application anyway.
 
I think what is happening here is, this is a dual field (squareback), and if you have the old style voltage regulator, then you must attach a small wire from the field terminal (the one nearest the ground screw) and attach it to the little ground screw thus grounding the field terminal to the case of the alt.
However if you are using the newer voltage regulators (triangle plug type) then you do not do any of what I just mentioned. What year is your Dart? Which alternator is this that you purchased?
 
Dart is a 72 Swinger. Engine is a 572 RB. Doing research, it seems all Mopars, no mater the engine size, had the same alternators. But, I could be informed, wrongly.
 
All Chrysler alternators have the same mounting points, the alternator you have is the last generation of Chrysler manufactured alternators before they switched to other brands. These later alternators were rated at 78 amps so you need to consider upgrading your electrical system. If you search this site, you will find tons of information on upgrades.
 
I agree w/ gdizzle. Perhaps Chrysler added that gnd terminal so they could drop the old round-back (1 grounded field) from dealer's stock and provide this single PN for older cars, along w/ a jumper to ground the nearby terminal if an older model. Perhaps someone could find a dealer PN for this mythical jumper to confirm.

Regardless, as TrailBeast said, it wouldn't hurt to run a thick wire (~8 awg) to the block to insure the case gets grounded. Sounds like the factory started doing so later. I keep telling the story when my 69 slant stopped charging 30 yrs ago, and same thing after I installed a rebuilt alternator in the auto store parking lot. I then got the bright idea to clip a jumper cable from alternator case to BATT- and bingo it started charging. Got a quick refund, drove home and sanded the alternator to bracket mounting points and no more problem. Stating "ground problem" can make you seem a genius 90% of the time.
 
All aviation versions of the Chrysler alternator are grounded field. All they do to convert an isolated field to a grounded field is remove an insulating washer and put the screw back in. I have seen jumper wires installed on isolated field alternators to ground a terminal, but they were all homemade. Here is a picture of the very last generation of Chrysler alternator. The ground wire is part of a molded harness and the field terminals are screw on. We may never know why Chrysler decided to start grounding the alternator.
1984 alt 4091424 (800x600).jpg
 
skykeith said:
All aviation versions of the Chrysler alternator ...
Click to expand...
Great info and photo.
"Aviation version" scares me since the square-back alternator in my 1982 Aries used to melt those 3 positive side diodes that hang in space every year, like clock-work. When it stopped charging, I knew to look in the square hole to find those 3 diodes gone. I got good at splitting the case open underneath the AC compressor, so I didn't have to remove that. I would buy just the diode pack at an auto-electric shop, and the guy there said my experience was typical. I think they kept the diode packs at the front counter, like a pharmacy I worked at in the 70's did w/ Valium bottles for housewives. By cutting cooling slots in the diode bracket I was able to get 2 years out of them. The 3 negative diodes get more cooling since their bracket bolts to the case. I suspect the problem was the alternator didn't get enough air flow in that transverse engine. An aircraft engine should have plenty of airflow, and I think they still use magneto spark, so the engine doesn't require the battery once aloft. Still, I would prefer a Denso in an aircraft.
 
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