1971 CDV - Alternator Originality

[impalamansgarage]

Hello all,

I have a question about alternator originality. Did a 71 Deville have an alternator with a pulley that looked like this:

http://www.partstrain.com/store/details/Cadillac/DeVille/Powermaster/Alternator/1971/P6657294.html?source=gglpla&gclid=CJjov5CYzssCFUQbgQodWmAAuQ


Or did it have a pulley that looked like this:

http://www.summitracing.com/parts/aaf-all80500?seid=srese1&gclid=COTizqqizssCFY4lgQodTG4LSw

Thank you!

[TJ Hopland]

The powermaster one in your first link is the 12si style that came in around 80 as an improvement (output, cooling, ect.) over the 10si style of the 70's.   The 10si (your summit link)was the first ones with the internal regulators which I think came out in 73.   The previous style pretty much looked the same as the 10si's but used an external regulator.   

[impalamansgarage]

The powermaster one in your first link is the 12si style that came in around 80 as an improvement (output, cooling, ect.) over the 10si style of the 70's.   The 10si (your summit link)was the first ones with the internal regulators which I think came out in 73.   The previous style pretty much looked the same as the 10si's but used an external regulator.   

Ok. My 81 had an alternator like that powermaster.

I don't recall seeing an external voltage regular under my hood.   

[impalamansgarage]

The numbers on mine say 63A. So according to this info, I guess it's a 10SI as you state.

http://www.madelectrical.com/electricaltech/delcoremy.shtml

[TJ Hopland]

Maybe it was 71 for the internal?   I'm sure someone here will know for sure.  I know by 73 they were internal.  The last 72 I worked on was a ambulance so it had the monster 110amp one.   The cases were basically the same for the external, internal 10si, and the 12si so they are easy to interchange.  There are even some newer ones that basically have the same case and most of the shafts are the same so pulley changes are also easy.

[Scot Minesinger]

Never seen an alternator on a Cadillac that looked like the first picture where there looks to be a shield between pulley and alternator, the second one looks correct.  The second alternator from that angle could be either externally regulated or internally.  If your Cadillac has an external regulator or not up on top of inner fender on passenger side closer to fire wall you will know what to buy.  Plus the plug into back of alternator is different connector for the external or internal regulators.

[impalamansgarage]

Never seen an alternator on a Cadillac that looked like the first picture where there looks to be a shield between pulley and alternator, the second one looks correct.  The second alternator from that angle could be either externally regulated or internally.  If your Cadillac has an external regulator or not up on top of inner fender on passenger side closer to fire wall you will know what to buy.  Plus the plug into back of alternator is different connector for the external or internal regulators.

You learn something every day. (hopefully) Thank you gents. Had no idea that this car had external voltage regulator. It's mounted on the firewall as you indicate. I went and looked.

Have owned the car for only a couple of months.

To be honest, I have a bit of a flicker on my interior lights at idle. The flicker seems to coincide with the
rotational frequency of the engine but subsides once the engine is off idle. (Or at least that is my perception)

Voltage regulator issue? I have a shop manual and just bought an old school analyzer that has alternator test functionality.

[impalamansgarage]

Never seen an alternator on a Cadillac that looked like the first picture where there looks to be a shield between pulley and alternator, the second one looks correct. 

My 81 came with a 100 amp alternator which looked like that powermaster. Very beefy looking.

[Scot Minesinger]

The flicker is usually due to a bad connection at the alternator, that is what happened to me.  Re-crimp the spades that plug into alternator (those two wires with plastic connector).  This connection is made ultra cheap, and I had to remake a good one - flicker coinciding with rpm gone for me.  Connection problem could be a volt reg or other places too - make sure they are all good.

["Cadillac Kid" Greg Surfas 15364]

Just to throw a monkey wrench in the works, a 71 Deville would have come with an externally regulated alternator. \
Greg Surfas

[TJ Hopland]

I looked it up and the reason the date of the internal regulator is fuzzy is it was apparently something that was phased in depending on models and options over a 4 year period.  It was apparently standard starting on 69 Corvette then presumably an option on some other models before becoming standard on most for 73. 

The enclosed fan was used on Cadillacs (and most other GM's) mostly in the early 80's till the later 80's when the cs130 came out which then had the older looking fan again, its higher output cousin was the cs144 that had the enclosed fan again.  The CS130D's came out mid 90's and had internal fans.

Quick way to tell if you have an internal or external unit is the externals had the 2 pin connector sticking out the back with the blades side by side the tall way  | | .    The internal regulators the 2 pin connector was on the side and had the blades side by side the narrow way - - . 

Scott's suggestion of checking the connector is good.   One of those small wires is the field circuit which is basically an electro magnet that makes the alternator generate power.   How much voltage goes to the magnet / field  directly relates to how much power is generated.  That is how the regulator works, if it senses that more is needed it ups the field power.   IF that power is not getting to the magnet the output won't increase.  At full output there is a fair amount of current there, no where near the output but certainly enough to cause issues with a marginal connection. 

["Cadillac Kid" Greg Surfas 15364]

TJ
Its a Cadillac not a Corbett.
Greg Surfas

[impalamansgarage]

I looked it up and the reason the date of the internal regulator is fuzzy is it was apparently something that was phased in depending on models and options over a 4 year period.  It was apparently standard starting on 69 Corvette then presumably an option on some other models before becoming standard on most for 73. 

The enclosed fan was used on Cadillacs (and most other GM's) mostly in the early 80's till the later 80's when the cs130 came out which then had the older looking fan again, its higher output cousin was the cs144 that had the enclosed fan again.  The CS130D's came out mid 90's and had internal fans.

Quick way to tell if you have an internal or external unit is the externals had the 2 pin connector sticking out the back with the blades side by side the tall way  | | .    The internal regulators the 2 pin connector was on the side and had the blades side by side the narrow way - - . 

Scott's suggestion of checking the connector is good.   One of those small wires is the field circuit which is basically an electro magnet that makes the alternator generate power.   How much voltage goes to the magnet / field  directly relates to how much power is generated.  That is how the regulator works, if it senses that more is needed it ups the field power.   IF that power is not getting to the magnet the output won't increase.  At full output there is a fair amount of current there, no where near the output but certainly enough to cause issues with a marginal connection.

Excellent info. Thank you. Very helpful. I removed the blade terminals (leaving the wires attached) from the two-slot connector at the alternator and cleaned them thoroughly with a wire wheel on my dremmel tool. Tightened them up with some pliers. I use a small flat blade screw driver and some sand paper to clean the terminals on the alternator as well.

Although the connections were in fact quite loose, there was no change in the flickering issue. I suppose I will look at the regulator next.

[TJ Hopland]

I don't know if parts stores can still test the external regulators or external alternators.  If their machines can I wonder if the operators could.     

Anyone know if the regulators in this era were solid state or where they still mechanical?    If they were mechanical there were slight adjustments that could be made and they did wear.   Solid state didn't have those issues, as far as I remember they were pretty much work or no work. 

The alternator itself contains the diodes that turn the AC the alternator generates to DC.  There is more than one diode so its possible to have one or more fail.  When that happens you basically end up with a 'dead spot' in the rotation.   The battery buffers and smooths things out so for the most part the result is just a weak output.       

Do you have an auto electric shop around?   If so I would take it to them for testing / repair.    IF you don't then ask parts stores if they can test yours but I would be cautious if its a bunch of kids running the place that can't do anything not in the computer.

[impalamansgarage]

Do you have an auto electric shop around?   If so I would take it to them for testing / repair.    IF you don't then ask parts stores if they can test yours but I would be cautious if its a bunch of kids running the place that can't do anything not in the computer.

Indeed. There is a shop down town that rebuilds alternators. I called them and described the situation. Quoted me around $70 to rebuild it. They said to bring the regulator in as well and they could test them together.

I think I will go this route. Will let you guys know how it turns out.

[impalamansgarage]

Here are the numbers off of my alternator in case anyone is interested.

1100557 63A
1F15 12VNEG

[impalamansgarage]

To finish up this thread, I did have the alternator rebuilt by Southern Armature in Birmingham AL. They said the rear casing was worn out but they had another one lying around that had the proper Delco name written on it. Anyway they rebuilt it and I bought a new solid state voltage regulator from them as well. I swapped the old regulator's cover over to the new one to keep it looking original.

No more flickering interior lights. Fixed !

The regulator is made by http://regitar.com/,  apparently Made in USA.