voltage regulator.

When did they stop using mechincal ones? How do you tell the difference between electronic and mechanical?

I ask because my alternator decided to take a crap. got a new 60amp alternator. Now i'm reading 16+volts at the battery. Not Good!

Well I know 69 was the last year for sure.I did have a 70 Imp that was electronic.The points type looks like a small rectangular box with a place for wires both ends.Looks like a small box.What tear car do you have?They do make a solid state reg to replace the points one.That and the alts are different.Early has only 1 field.Late looks like squares and has 2 field wire connectors.Rocky

The car is a '71 Demon with a 383 out of a '69 roadrunner. When I got the alternaot I told them for a '69 rr. When I had probelms years ago I told them I needed one for '69rr. I dont know how to tell how many fields there is. But its a three wire alternator.

last year was 69, HOWEVER, I have known some later 69 C bodies were already electronic. In fact some 69 alternator units already had the provisions for both isolated brushes, but still round backs alts.

you can use squareback or roundbacks alts with any regulatro as far you have it wired correctly

NORMALLY roundbacks alts are with one brush grounded, directly attached to housing. Those where designed to work with mechanical regulator, sending regulated positive source throught green field wire

Then Square back alts are with both brushes isolated, to get constant positive from ign key throught blue wire field and regulated ground coming from elect regulator, throught the green field wire. For obvious reasosn both need to be isulated from chassis

Now you can make work and mix any setup. You can modify a roundback alt/one brush isolated drilling a hole on hosuing ande fit the secondary isolation setup brush. to use with electronic regulator, and making a slight wiring modification

Same about squarebacks alts, grounding one brush ( with a wire to chassis or replacing the isolation washer for a metallic washer ) and use that one with mech regulator. BEING SURE NOBODY HOOKS THE FIELD WIRE on the grounded brush, because will short.

With roundbacks alts setted for both setups, you need just to set the right brush setup and fit it on housing to match with any engine harness wiring and regulator kind

if your 71 is still correcty factory setted, you must get the squareback alt and elect regulator. Thts is thre wires... green ( regulated source, negative ) blue ( constant source, positive ) and black ( alt positive output to ammeter ).

if you got a 69 alt and is three wires, you have the roundback alt with chance to both setups. Works exactly the same than a squareback alt, just not the correct date to your 71

After reading that five times I am still somewhat confused. Is there any way to provide pics of the alt.'s and regualtors you speak of?

When you say square back does that literally mean there is a square somewhere on the back of the case? And round would be an all round back? If thats the case I would say I had a square on the car and was sold a round.

Also will a mech. and elc. regaulto have the same connector?

Electronic OEM regulator for dual field wire alternator is flat rectangular shap with a triangular shaped plug in in the front of it.
The older single field wire regulator had a connection for wires at 2 places and was more squarish and taller voltage regulator . Here is a picture of the newer style electroninc regulator for a dual field wire alternator. http://www.bouchillonperformance.com/BPE5310-11.asp

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After reading that five times I am still somewhat confused. Is there any way to provide pics of the alt.'s and regualtors you speak of?

When you say square back does that literally mean there is a square somewhere on the back of the case? And round would be an all round back? If thats the case I would say I had a square on the car and was sold a round.

Also will a mech. and elc. regaulto have the same connector?

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Forget all the round/squareback stuff for now

Alternators don't have "two fields" they have an ISOLATED, meaning UNGROUNDED field so......

up to 69 had a GROUNDED field, so it had one big stud for output/ battery, and one push on connector

70 and later ADDED on more push-on connector. They simply UNGROUNDED the field and brought the connection out.

NOW WHERE THIS GET'S STICKY---some rebuilders MODIFIED old cases and added the insulated field connector---so it's possible to find an OLD roundback off a 69/earlier WHICH HAS two push on connectors---this is useable on the 70 and up

You can use the late isolated field on ANY year by grounding one field connection.

You can NOT USE the early alternators with a 70 and later alternator UNLESS, as above, some rebuilder has added the isolated/ second connection.

There are THREE regulators

The old up to 69 "popular" car regulator

The old up to 69 heavier duty "truck" regulator, about twice the size of the "popular" one

Both of the above have two wire connections--FIELD and IGNITION (and ground!! the case)

The late '70 and later electronic/ isolated field regulator, which has the triangular connector