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alternator voltage questions

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Jun 16, 2009
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I did some searching and it seems if the alternators in our cars arent running at pretty close to a full 14 volts it can cause problems. Mine at idle will drop down to low 11 volts at the back of the alternator and into the 10s on the scanmaster im wondering if this can be the cause of some of the issues ive been experiencing. Im also noticing that if i leave my car on the battery tender the voltage at the battery is about 13.1 or so but if i start the car and let it idle for a while itl will be around 12.5. any advice is appreciated. also it did have a reds volt booster installed on the car when i bought it, but I have removed it.

Thanks
Dave
 
Does the voltage come up when you bring the rpms up? Does the engine have a small diameter crank pulley or the stock one?
 
the voltage does come up with rpms but im having problems at cruise and even at cruise rpms the voltage is still low on the scanmaster around low 12's
 
here are my thoughts as we now just hooked with a local source that is building us correct 120 amp alternators 2 year warranty pre-tested with all new parts.

See advertising specials...the ones on our cars 1986-1987 are quite unique from what I found no other GM car during that time frame had a 120 amp alternator...we even now have figured out the codes. (Same one appeared in 1989 on the limited edition turbo trans am.)

You mention the car had at one time a volt booster kit on it....I have been told over the years by several sources that method of jolting the alternator is not good for them. I am not saying it can lead to problems only that it can be an issue.

I am only giving you options as I am far from an expert with the problems related to your car....and if you want to go 100% brand new we have the solution. The popular method to get the proper constant 12 volts to the fuel pump is Caspers method....

Also make sure you have the correct pulley on the alternator, your battery is fully charged, correct gauge cables to the battery, and the tensioner is in the correct range.

Because if all that is not correct even our new alternator will not be the "savior" you seek.
 
Id definatly be interested in you alternator can it be ordered direct off your site if not can you pm me a price shipped to 23608? is there a warranty on it?
 
Id definatly be interested in you alternator can it be ordered direct off your site if not can you pm me a price shipped to 23608? is there a warranty on it?

They are not yet on our website.

You got two options...

The more expensive option is to buy our new one which everything is new except the pulley which is used...pulley and stator is painted black just like the original was. Alll internals are 100% brand new. They are in stock but not yet on website. Our part number is #7315 and they are on sale until March 18th sale price is $154.95.

Unit weighs 16 lbs probably $12-$15 at the most to ship....

Second option: If you have an original correct alternator we can rebuild that for you with all new internals and turn it around in 5 days. Again same 2 year warranty also pre tested. Your cost would be $139.95 plus same shipping.

I am basing all this on the fact you own a 1986-1987 Turbo Regal. If yours is original it will have the correct part number and date stamp on it so that way its kept original...new ones we sell housing has no codes on it.

Point being you got two options.

Your choice...

You would have to call my office during normal work hours to order 215-766-1611 since none of these are on the website as of yet. However if you go to our website main page look for turbo inner circle dated last week we cover all the info on the new alternators and even picture the new one I am referring to...yours rebuilt would look just as nice.

choice is yours

denniskirban@yahoo.com
 
It's a CS144 alternator they made a lot of them over the years and even upgraded them to 140 amps. for the Impala SS.

Pep Boys had Prostart new ones available when I needed one.

The voltage depends a lot on the battery and it's current state of charge.

As well as load and wiring condition.
 
It's a CS144 alternator they made a lot of them over the years and even upgraded them to 140 amps. for the Impala SS.

Pep Boys had Prostart new ones available when I needed one.

The voltage depends a lot on the battery and it's current state of charge.

As well as load and wiring condition.

Its true they did make a lot of them however in 1986-1987 from the books I have only Buick in the turbo applications had them.

I have researched at least two companies that do in fact make new ones...2 issues....one the startor section is usually grey or gold when in our cars it was black.

Second issue they generally go with a generic pulley and in both cases we found the pulley was actually smaller than the correct one which as you know can pose charging problems since its not the proper size.

Granted many options exist and we even now offer a 200 amp alternator and a later better fan for cooling....We have geared our product towards the owner that is interested in having the most correct looking alternator on their car. You pay more but its because they are not massed produced for the general public.

denniskirban@yahoo.com
 
Yes the pulley needs to be swapped usually.

I am sure a direct look alike NOS 120A alternator will sell just fine and be a great option for a lot of people.

I needed mine same day so I could get to work the next day. ;)

Prostart new not a rebuilt used to be around $130 but that was 7 years ago. :eek:

Most any local shop can get the parts for them too, they are not that hard to rebuild either by yourself or at a local shop.
 
Also make sure you have the correct belt!

Napa , Advance and Autozone all list the 640 as the correct size for the Vin 7 Regal. I had slipping (and clatter that sounded like valvetrain noise :eek: ) and voltage issues at WOT using the 640 belt. I switched to the 635 belt and issue resolved!
 
what pulley is supposed to be on the alternator to make sure i still have a stock pulley as i am 99% sure this is a replacement alternator. Im not sure how to verify if i have the correct pulley size in case thats whats causing low voltage at low rpm
 
what pulley is supposed to be on the alternator to make sure i still have a stock pulley as i am 99% sure this is a replacement alternator. Im not sure how to verify if i have the correct pulley size in case thats whats causing low voltage at low rpm

others can chirp in I happen to have a stock pulley on my desk since we are getting alternators now done...

it is black pulley tip to tip diamater is just a tad under 2 3/4 inches...

denniskirban@yahoo.com
 
Typically when an alternator puts out low voltage, I look at the diode bridge, first. In my case it was usually the diode by the output terminal that overheated due to high resistance at that terminal.

The CS 144 is easy to rebuild. I have attached an old article that explains in detail how to do this. Look around for a local rebuild shop for parts. You can usually get the parts for considerably less than the dot - com sites want for diode bridges, regulators, brush assemblies, upgrade stators and bearings if you shop around.

For upgrading to over 140 amps I would chose a 1996 up CS 144 alternator rear case with the upgraded diode pack and rear bearing. Even the output terminal is larger requiring a connector with a larger hole to fit properly. Do not enlarge the hole in the stock wire or the alternator will not last long as high resistance will heat the diode bridge. Don't ask me how I know.
 

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