CS144 Alternator Conversion
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Tired of 85 to 95 AMPs of power? Well this simple swap will get you 140 AMPs of juice to power most everything any regular driver will need. With my aftermarket CD player (no subs), headlights, A/C, and wipers going, I am still hitting over 12.5 volts. With my old SI alternator I was lucky to hit 12.5 with nothing on!
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Supplies

CS144 Alternator - you can get these from any parts store if you ask for an alternator for any of the following:
(1994-96) Buick Roadmaster 5.7L
(1993-96) Cadillac Fleetwood Brougham (RWD) 5.7L
(1993-96) Chevrolet Caprice 4.3L, 5.7L
(1995-96) Chevrolet Impala 5.7L
(1992-95) Chevrolet Lumina APV Van 3.8L
(1992-95) Oldsmobile Silhouette 3.8L
(1992-95) Pontiac Trans Sport 3.8L
AC Delco part 10463338.
Picture - CS144 alternator:


Wiring harness/adapter - if you have a parts store that knows anything you should be able to go in and ask for an "SI to CS conversion harness" otherwise just go to the dealer and ask for:
Delco 8078/GM 12102921 if you have a volt gauge or
Delco 8077/GM 12083462 if you have an "idiot" light.


Picture - Wiring harnes (8078) (note the resistors in the wires)


Optional:
Alternator bracket kit - I've read many reports about the CS alternator not fitting properly so that the user is not able to tighten the brackets all the way. In my install I was able to install everything perfectly with no fit problems at all. You can go chrome universal (Spectre or Mr. Gasket)
Picture - my stock bracket:

Picture - Chrome bracket:

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Directions

1. Unhook negative battery cable.
2. Loosen alternator and remove belt.
3. Remove alternator.
4. Change alternator pulleys if necessary (use an impact wrench)
5. If you are using the stock brackets, the arm on the lower bracket will not bolt on to the alternator. That is OK. The lower bracket is used just to support the weight of the alternator. Simply loosely attach the top of the alternator so you don't have to hold it up. Next put the lower bracket in between the block and alternator, slip the long bolt through and tighten into the original hole on the block.
Pictures - lower bracket:


6. Loop belt around all necessary pulleys and back around alternator pulley.
TIP: Use the best belt you can find. When I first did this swap, I used a 5 dollar belt. Every time my alternator kicked in my belt would squeak for a few seconds. I went back and got a Gates belt (23 bucks) and no more squeaks.
7. This is easiest if you have two people. The CS style alternators are meant to be in cars that have serpentine belt systems so the top hole is not threaded like the stock alternator. You will need a big bolt and a big nut (I don't know what size specifically is needed, I just found something in my garage). Next pull back on the alternator and have your buddy tighten the nut/bolt with two wrenches.
8. Plug in wiring harness and reconnect the tickle/trigger wire.
Picture - Wiring harness:

9. Reconnect battery wires.

Picture - Final install:

Be careful of the plastic fans and high rpms.
I had one come apart at the track and it cut though the hood and beat up both fenders, due to high rpm (8000) with standard drive pulleys the steel fan is a direct replacement.
I don't know the part # but I called powermaster and they sent me a metal replacement that bolted right up that looks like the stock fan from the older alternator.

Nice writeup!

Another way that I have used to tighten the belt is to use a pry bar and that circular hole in the top of the alternator bracket. Use a rag if you are afraid of marring your alternator and/or bracket.

when I put my cs-144 in I drilled and tapped a 3/8" x 1" piece of steel on the upper alt bolt and just used a regular wrench to tighten up. Steve

what is the purpose of the resistors,and are they req'd?

The resistors provide a "tickle" for the charging sensor. The alternator was designed for a car that has a "dummy" light, which provides resistance for that sensor. So, if your car has no dummy light, there is no resistance, so there has to be a resistor somewhere in the system to provide a load.

What if I have the plug from the donor car and want to merge the harnesses what do I do for resistors? And which of the two small wires do I use?

an upper alt bracket from a car or truck with HD charging will bolt right up- they have at he bigger 14SI alternator that puts out like 120 amps. look under the hoods of Caprice cop cars and station wagons. you can even get the spacer thing on the big lower bolt and bolt it right up to the newer alternator if you want it to look really stock.
if you want a bolt in alt that has a threaded upper hole, then get one for a 97 Olds Aurora. they are 144amps and have a bigger lug on the back for the charging wire.

I may have to look into getting a different upper bracket.

My stock 1986 bracket works, HOWEVER I did not like how it fit.

I started installing the alternator by bolting it on with the bottom bolt and bracket (left loose).

I then installed the upper bracket and left the bolts finger tight. Next I tried rotating the alternator into position and no go... It hits the bracket.

I tried removing the bolt that holds the alternator bracket into the intake manifold. That helped but I didn't like only having two bolts holding the alternator in place. I then tried prying up on the upper bracket to make it fit, the move I moved it up the more the bracket moved forward. So I said heck with it and ran a bolt through and tightened it up. Well it didn't looks straight. So I ended up using the lower bolt as a guide for keeping the alternator straight and in place while I fooled around with the upper bracket. End result was three washers between the upper alternator bolt and the upper bracket. Now if anyone looks under my hood they probably will never know the difference. But it bugs me that I had to use three washers to keep the alternator straight.
I will be on the look out for a new set of brackets.

All in all it's still a great upgrade.

Down at the bottom of the link below, you will find a wiring diagram for the ALT, you only need to add a 50 ohm 5 watt resistor to the L wire. This is a 25 cent resistor!! and the the adapters are like $20.00 plus $8-9.00 shipping now... HTHs

http://www.gilbertautoparts.com/ChevySmallBlockV8s/385turnkeyparts.cfm

im looking at getting 1 of these in a week. Im not sure i understand the whole resistor deal. The alternator wont work properly if there isnt a resistor? My volt gauge isnt being used right now and voltage isnt hooked up, can i jes bolt the new ALT up, not connect volt connector and be fine?

I just finished doing this upgrade this afternoon. Here are some things that I found as I went through that are not listed in the original post, but may be helpful to those considering this...

First, a question I had a while ago, you don't have to upgrade your battery cables to do this.

Seconds, it is possible to use the stock alternator bracket, however the spacer on the long bolt that goes between the alternator and the block is bolted to the stock alternator. You will have to unbolt it. It will not bolt to the CS style alternator, so just slip it over the long bolt. Also note that the upper bracket will have to be unbolted from the intake manifold. The CS alternator is larger that the SI, and you can't use the stock upper without unbolting it from the manifold. It may be possible to modify the bracket so that you can keep it bolted to the manifold, but I didn't bother trying and I'm satisfied with the tightness of the new alternator using the upper bracket without the manifold bolt.

Third, on the CS alternator I used (this may or may not be true of all CS alternators, I don't have access to another one to check), the stud on the back that you bolt the battery wire on to is larger than the one on the original SI alternator. Since the terminals are O ring contacts, I modified them by cutting the "O" with a pair of dikes and gently spreading the contacts open, into more of a "U" until they fit over the stud. I'm sure you could just replace the contacts with larger ones, but I didn't happen to have any on hand.

Overall this was an easy upgrade, and I completed it in about an hour and a half. I spent most of the time tightening the belt so that it wouldn't squeal under load.

I checked my battery with a multimeter when I finished, and it read 13v at idle, so I turned on the headlights, high beams, rear defrost, and AC on high. It only dropped to 12v (would drop to about 8.5v with the old alternator), and when I revved the engine in was right back to 13v. No more flickering headlights when the turn signal is on!!

Here's a bit more technical electrical information for the CS style alternators.

The 4 pin plug has connections marked S, F, L and P. NOTE: If your alternator as an 'I' in place of the 'L' connection, see the paragraph below.

S = Sense
F = Failure (Indicator)
L = Lamp
P = Pulse

The 'S' connection connects to a remote voltage sense location. This wire connects to the larger gauge wire that was on the stock SI alternator connector (Not the thick battery wire that connects to the rear of the alternator). As it sounds, the alternator uses this connection to sense the remote voltage to determine if it's sagging (more current required), or not (less current required).

The 'F' connection is the failure indicator and is not used for our setup. It normally would go to a alternator failure indicator in some setups (as opposed to an alternator lamp).

The 'L' connection is the lamp connection. The 'lamp' refers to the typical idiot light for an alternator. This connection requires switched (ignition) voltage through between 35 and 350 ohms of resistance. If the alternator sees below 35 ohms of resistance, the CS alternator will fail eventually. For the 4th Gen Monte Carlo SS, the thin brown wire that normally went to the stock SI alternator is switched voltage, but the resistance is too small. I measured mine at 15 ohms to ground. Since this is less than the 35 ohm minimum requirement for the CS alternator, you need to add a resistor in series with this brown wire, to the 'L' lamp connection. I chose a 40 ohm 5 watt resistor. As long as you keep the total resistance between 35 and 350 ohms, you should be ok. If in doubt, measure the resistance of your brown wire to ground with ignition off to determine your car's baseline resistance.

The 'P' connection is not used in our application. It's a pulsed output that connects to a tachometer in some applications.

For alternators that have an 'I' connection in place of the 'L' connection, the wiring requirements are a bit different. See this link for more information.

Depending on the exact model of alternator you purchase, the rear battery connection may not be convenient, or come too close to other engine components. In this case, you can remove the three bolts holding the alternator together to re-clock the rear. Because of the bosses on the altnerator, you will have to separate the two halves. Be forwarned that doing so will cause the alternator brushes and springs to pop out. Putting them back is simple by using a straightened out paperclip, inserted into the whole at the rear of the alternator which allows the brushes to be held in place while the alternator is apart. Once you have the alternator properly clocked, and the three bolts retorqued, simply remove the paperclip from the hole to release the brushes.

This information should apply to all CS style alternators, whether installed in the stock location on the passenger side of the engine, or on the driver's side of the engine in a serpentine belt setup.

The plug that i have only have wires coming out of the F and L hole. So without the adapter will both wires be connect to the brown wire from the harness with the resistor on the L wire?

You should only use the L connection, with the appropriate resistor in series to the stock brown wire. Do not connect the F connection to anything.

How do you change the pulley on the alternator? I have a serpentine setup....its like 6 grooves. If i find a CS alt with a V-style belt, i wanna be able to change it.

I had to change my pulleys, but it works fine one the best upgrades I ever done, besides the head lights.

With the stock bracket I leaft the bolt at the intake loose and tightened up the alternator, then tightened up the bolt. It tweaked the bracket enough that I could get the bolt tight. I also had to "clearance" the groove enough for a larger bolt to fit through. The upper hole is larger and not threaded so you have to find a larger bolt to fit in it.

That stud on the back was also larger on mine. I keep lots or wiring connectors around so I just put a larger one on. I also swapped out to my original v-belt pulley and have not had an issue. It was approximately the same size. I only paid $20 for my alternator but ordered the harness instead of trying to make one.

The serpentine and v-belt pulleys should be interchangeable. I just received a new aftermarket CS unit and the dummies sent it with a v-belt when it was spec'd for a serp. The aftermarket units are available with both. I'm pretty sure all OEM units were put on cars after v-belts were totally phased out.

Great write-up! Round up a Chrome fan and pulley. Tape off the holes, shoot a coat of gloss black paint and voila! Looks sharp!

will this work on 4.3

The conversion should be the same in every respect!

anyone have a link to purchase the alt online. i checked ebay no luck tho

http://paceperformance.com/index.asp?PageAction=VIEWCATS&Category=8710

Beware of the Tuff Stuff alternators if you want it in a timely fashion. Pace thinks they are high quality, but they are basically custom built and it took me at least five weeks to get mine, and another week to get the correct pulley! Other than the delays, it seems like a nice unit...

I got mine at Autozone. Should be able tyo get them at Checker, O'reileys, Rockauto, etc. Look up any of the cars listed in the first post of this topic. Got mine for a pontiac transport.