News:

Due to a technical issue, some recently uploaded pictures have been lost. We are investigating why this happened but the issue has been resolved so that future uploads should be safe.  You can also Modify your post (MORE...) and re-upload the pictures in your post.

Main Menu

1970 Deville Alternator Wiring

Started by Jvteach07, January 08, 2021, 08:01:47 PM

Previous topic - Next topic

0 Members and 1 Guest are viewing this topic.

Jvteach07

Just wanted to know if anyone could help me fix the wiring on the Alternator. I just inherited this car and went to replace the Alternator and found that it was a different brand that was installed last. The one I purchased was an original Delco part. I circled the connector that I  think is supposed to be connected to this new alternator but I don't know what to do with the connector plugged in now.
Joe Tortora
1970 Cadillac Devill Convertible

chrisntam

The alternator pictured has an "internal" regulator, it is a later style alternator, not originally available on a '70.    Some folks "convert" their cars to this style alternator though, it appears yours is one of them.  Internally regulated alternators started showing up around 1973, I think.

The original alternator had an "external" regulator, which has different connections than the one pictured.  If it was me presented with your situation, I'd take the old alternator in, match it up, hang it on the car and see if that fixes your problem.
1970 Deville Convertible 
Dallas, Texas

Jvteach07

So bring the old alternator into the parts store and try to find a similar one?

Thank you
Joe Tortora
1970 Cadillac Devill Convertible

Cadman-iac

#3
Quote from: Jvteach07 on January 08, 2021, 09:04:45 PM
So bring the old alternator into the parts store and try to find a similar one?

Thank you

Yes, if it was my car, I would just replace the alternator with an identical one. The one you have is a much better unit, and a lot more dependable.
But before you purchase another one, take that one in and have it tested first. It may not be the problem, and simply replacing it without checking may cost you more than necessary.

Rick

Edit; if I may ask, have you checked out the battery? A battery can show to have the correct voltage but not be able to provide the amperage to start the engine due to an internal problem.
How did you determine that your alternator was bad?
CLC# 32373
1956 Coupe Deville A/C car "Norma Jean"

Bill Balkie 24172

Hello Joe ,
      A year ago I ordered a new alternator for my car to have as a spare . I found that the new alternator was a Delco  however is was assembled 90 degrees clocked the wrong way . I disassemble the new alternator and reassembled it the correct way so the wires would connect the same way . I put that alternator in the car and it worked fine . I decided to get my original alternator rebuilt and keep the new one on the shelf as a spare . I also have the external voltage regulator . I have added a few pictures of how my alternator is wired . I hope this helps 
Bill Balkie
1970 Coupe DeVille
2009 CTS

TJ Hopland

If you go in and ask for say a 75 Deville alternator you should get one with the same connectors but the connectors will be up instead of to the side.   This vintage Cadillac's had them up which doesn't look like it would be a problem for yours since the wires will be long enough to reach.    Its when the new position is farther away that the wires may not reach or if they connectors are blocked by something you can't make it work without re clocking the unit which can be a hassle. 
StPaul/Mpls, MN USA

73 Eldo convert w/FiTech EFI
80 Eldo Diesel
90 CDV
And other assorted stuff I keep buying for some reason

bcroe

#6
I would recommend, determine for sure just what the car is wired for
now, internally or externally regulated alternator.  Look around for a
mechanical voltage reg.  Then you can see what to do next. 

Here I am entirely in favor of the internally regulated alternators.  Only
one part to troubleshoot, and much simpler wiring once it is cleaned up. 
Generally its a mechanical bolt in, wired as a mid/late 70s alternator. 
Clocking around the cover is easy if it is pried up JUST BARELY enough
to be rotated.  If pulled farther out, the brushes will pop out and need
to be properly restrained for the reassembly.  Bruce Roe

chrisntam

What is the benefit of the internally regulated alternator? 

Is it only one less part to troubleshoot or are there other benefits?
1970 Deville Convertible 
Dallas, Texas

bcroe

Quote from: chrisntamWhat is the benefit of the internally regulated alternator? 

Is it only one less part to troubleshoot or are there other benefits?

Yes its a lot simpler to troubleshoot and repair, with only one main component and
3 wires.  Probably parts are getting more available as well.  It also eliminates the
radio interference, and possible failure, of the field current regulator.  I am happy
to see another box under the hood gone. 

I think the first alternators, like the generators before them, tended to have a
smaller output rating.  Instead of 30-60A of the original mechanically regulated,
you see 60A and up with internal reg.  Bruce Roe

Glen

Quote from: bcroe on January 10, 2021, 12:23:24 PM
Clocking around the cover is easy if it is pried up JUST BARELY enough
to be rotated.  If pulled farther out, the brushes will pop out and need
to be properly restrained for the reassembly.  Bruce Roe

I have done that several times.  It is easy.  The last one came with instructions on how to clock the alternator.  But they left out the part about  opening it up only just enough to turn it. 
Glen Houlton CLC #727 
CLCMRC benefactor #104

fishnjim

There were issues with the first gen alternators, so this might have been done long ago from the looks of things, quite a corroded engine compartment.
1: can rebuild what you got.   Should have a number on it somewhere.
2: get one like it.
3. convert back to stock.   Need wiring diagram and correct P/N alternator, connector. which might be what you purchased.
I vaguely recall it's a one vs two wire system, but by rote.   Havne't changed an alternator since early 2000s and when replacement went bad I took to garage, such a pain to get to on a north star.

No issue rotating the end to position/clock the direction of the connector.

ps: I'm going to move on and go back to my first other brand project so won't be posting much from now.   PM any questions.   2020 had plenty of time, not so in 2021.

Jvteach07

Thank you for all the help. I ordered a 1973 alternator and it matched the one in the car that must have been upgraded before. Its off to be re-painted so I will post updated photos in March. Thank you all for your help in getting this project completed. Looking forward to the spring and summer!
Joe Tortora
1970 Cadillac Devill Convertible

mamaliga

#12
If you have inherited this machine, the best thing is to replace the alternator. The old alternator can no longer produce the amount of electricity it should. I recommend that you carefully choose a new alternator that is right for you. Alternator average price depends on many factors, so you have to choose the important factors. Some people care about durability, while others care about performance. If you decide to buy an alternator on the aftermarket, I recommend hiring a mechanic to help you choose.

bcroe

I do not agree, an old alternator will continue to produce the
same amount of current as new, until there is a component
failure.  Bruce Roe