SI to CS alternator - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**72tutone** · 04-17-2015, 10:58 AM

I have an SI alternator external voltage regulator now. I just purchased an 94 s10 blazer 4.3 serp setup.
I've read somethings that arent quite definitive in my eyes.

Can I just by the adapter and call it a day? Does it need to be the one with the resistor?

I have an 72 with an ammeter. What direction do I need to go down to get this to work?

Thank you

**72tutone** · 04-17-2015, 11:06 AM

I have an SI alternator external voltage regulator now. I just purchased an 94 s10 blazer 4.3 serp setup.
I've read somethings that arent quite definitive in my eyes.

Can I just by the adapter and call it a day? Does it need to be the one with the resistor?

I have an 72 with an ammeter. What direction do I need to go down to get this to work?

Thank you

**DeadheadNM** · 04-17-2015, 11:22 AM

I went with the easy, plug-and-play harness adapter with two motors now and both worked fine.

**72tutone** · 04-17-2015, 11:23 AM

Quote:

Originally Posted by DeadheadNM

I went with the easy, plug-and-play harness adapter with two motors now and both worked fine.

What about the external regulator. Can that be yanked out? Or is it still required?

enaberif · 04-17-2015, 11:31 AM

I used Napa ECHLIN EC82 with resistor for my 74 that had a ammeter.

**72tutone** · 04-17-2015, 11:44 AM

Quote:

Originally Posted by enaberif

I used Napa ECHLIN EC82 with resistor for my 74 that had a ammeter.

So nothing more is needed then? Did you yank your external regulator out? Or is that still needed in some capacity?

enaberif · 04-17-2015, 11:50 AM

Quote:

Originally Posted by 72tutone

So nothing more is needed then? Did you yank your external regulator out? Or is that still needed in some capacity?

SI alternators use internal regulators so you don't require your external anymore.

I'm not 100% on the external regulator stuff because my truck may or may not have had it..

**72tutone** · 04-17-2015, 11:54 AM

Is the factory alternator year an SI?

If that was the case Im not sure why the external was even needed then?

Now Im super confused. I just yanked the alternator from my serp setup off a blazer with part numb DLG 1345-6-7 which I believe is an CS130 style alternator.

57taskforce · 04-17-2015, 01:22 PM

From the factory they all had external regulators as far as I'm aware(could be wrong) at least everyone I've ever seen did. I'm sure lots of them have had internally regulated units swapped in by now.

**72tutone** · 04-17-2015, 01:35 PM

57taskforce that is true as far as I know too.
The part numb I referenced DLG 1345-6-7 is internally regulated. I didnt know if I used this adapter harness can I just remove the external regulator. But since the external reg wires run to the factory alternator this harness really is just an adapter for the existing wires, so to me it looks like the external regulator needs to be left alone. But just use the ECHLIN EC82 to hook to the new alternator.
I dont know lol. Thats why I'm here to ask the experts

MARKDTN · 04-17-2015, 02:46 PM

Do yourself a favor and get rid of the CS130 alternator and go to a CS144. Same plug. Some mods to the mounting are required. But as far as I am concerned a CS130 is no good as a paperweight.

**DeadheadNM** · 04-17-2015, 08:15 PM

Quote:

Originally Posted by 72tutone

What about the external regulator. Can that be yanked out? Or is it still required?

Yank it out. The conversion kit includes a female adapter that plugs onto the harness for the regulator that I believe also serves to bridge some of the circuits (but not completely certain).

clinebarger · 04-17-2015, 09:30 PM

It's already rewired for a Internally Regulated SI alternator, And you need to rewire it (again) for a CS alternator?

Your existing SI Alt. has 2 wires going to the regulator, The #1 terminal is wired to the Generator Lamp, Or a resistor wire (depending on the cluster).
The #2 wire is a battery hot, Will not be used on a CS Alt. You can put a ring terminal on it & run it to the charging post, Remove it from the harness, Or Tape/heatshrink the end so it doesn't short against anything.

The Generator Lamp wire will go to Pin "B" on the CS regulator plug, Some Connectors are labeled "L" (For Lamp).

A Ignition Hot "MAY" need to be wired to Pin "C" on the regulator plug, Some Connectors are labeled "F" (For Field)....Most CS Alternators Do Not need this to turn on & charge, But '94 S/T trucks show it in the diagrams.

**VetteVet** · 04-18-2015, 12:01 AM

Maybe this will help you.

http://67-72chevytrucks.com/vboard/s...d.php?t=567472

**truckdude239** · 04-18-2015, 08:05 AM

XIV. Multiple Posting - It is simply not acceptable to post your question more than once, or to post it in more than one forum. Choose the forum that your question or post best fits in, and place it there and only there. If, after posting, you feel it should be in another forum, private message the forum Moderator and ask if they would move it for you.

your threads have been merged

04-17-2015, 11:22 AM	#3
DeadheadNM Carpe manana Join Date: Dec 2010 Location: Eau Claire, WI Posts: 12,301	Re: SI to CS alternator I went with the easy, plug-and-play harness adapter with two motors now and both worked fine. __________________ 1972 K5 CST Highlander Blazer: http://67-72chevytrucks.com/vboard/s...d.php?t=708547 1972 K20 Cheyenne Super: http://67-72chevytrucks.com/vboard/s...d.php?t=528308 Members met: ORANGBLAZ, 2003 silverado, MikeCofield, BB72CHEVKT, Duncan&Son, Sameyrasmea72, THENEWMEXICAN, HotRod C/10, brianthelion02, Sport/Truck, ryanroo, michael bustamante, Dirt's72, Already Gone, WestButteTruck, 57taskforce, Moreyel, painterljp, AASmedic, SoCoC10, Lumaestas, carbuff382, Chevyland

04-17-2015, 11:31 AM	#5
enaberif Registered User Join Date: Jan 2009 Location: Calgary, AB Posts: 1,181	Re: SI to CS alternator I used Napa ECHLIN EC82 with resistor for my 74 that had a ammeter.

04-17-2015, 11:54 AM	#8
72tutone Senior Member Join Date: May 2010 Location: St.Louis Posts: 635	Re: SI to CS alternator Is the factory alternator year an SI? If that was the case Im not sure why the external was even needed then? Now Im super confused. I just yanked the alternator from my serp setup off a blazer with part numb DLG 1345-6-7 which I believe is an CS130 style alternator.

04-17-2015, 01:22 PM	#9
57taskforce All about them K’s Join Date: Jun 2014 Location: Farmington, New Mexico Posts: 6,244	Re: SI to CS alternator From the factory they all had external regulators as far as I'm aware(could be wrong) at least everyone I've ever seen did. I'm sure lots of them have had internally regulated units swapped in by now. __________________ Tyler '57 3100 http://67-72chevytrucks.com/vboard/s...d.php?t=813888 '72 K20 Cheyenne http://67-72chevytrucks.com/vboard/s...d.php?t=662879 ‘69 K10 SWB http://67-72chevytrucks.com/vboard/s...d.php?t=805206 '98 Silverado LT K2500HD ECLB Vortec 454/4l80E: 6" lift 315/75/16's ‘87 IROC-Z all original 50K mile survivor TPI 305 IROC Blue ‘10 Camaro 2SS/RS Aqua Blue Metallic #93 -version 2.0

04-17-2015, 01:35 PM	#10
72tutone Senior Member Join Date: May 2010 Location: St.Louis Posts: 635	Re: SI to CS alternator 57taskforce that is true as far as I know too. The part numb I referenced DLG 1345-6-7 is internally regulated. I didnt know if I used this adapter harness can I just remove the external regulator. But since the external reg wires run to the factory alternator this harness really is just an adapter for the existing wires, so to me it looks like the external regulator needs to be left alone. But just use the ECHLIN EC82 to hook to the new alternator. I dont know lol. Thats why I'm here to ask the experts

04-17-2015, 10:58 AM	#1
72tutone Senior Member Join Date: May 2010 Location: St.Louis Posts: 635	SI to CS alternator I have an SI alternator external voltage regulator now. I just purchased an 94 s10 blazer 4.3 serp setup. I've read somethings that arent quite definitive in my eyes. Can I just by the adapter and call it a day? Does it need to be the one with the resistor? I have an 72 with an ammeter. What direction do I need to go down to get this to work? Thank you

04-17-2015, 11:06 AM	#2
72tutone Senior Member Join Date: May 2010 Location: St.Louis Posts: 635	SI to CS alternator I have an SI alternator external voltage regulator now. I just purchased an 94 s10 blazer 4.3 serp setup. I've read somethings that arent quite definitive in my eyes. Can I just by the adapter and call it a day? Does it need to be the one with the resistor? I have an 72 with an ammeter. What direction do I need to go down to get this to work? Thank you

04-17-2015, 02:46 PM	#11
MARKDTN Registered User Join Date: Jan 2011 Location: Chattanooga, TN Posts: 2,135	Re: SI to CS alternator Do yourself a favor and get rid of the CS130 alternator and go to a CS144. Same plug. Some mods to the mounting are required. But as far as I am concerned a CS130 is no good as a paperweight. __________________ '83 K20-TPI '73 C10 '79 C10-ex-diesel(SOLD) '07 Tahoe(Son driving) '14 Suburban-DD '71 C10-current project

04-17-2015, 09:30 PM	#13
clinebarger Senior Member Join Date: May 2009 Location: Fort Worth, TX Posts: 6,370	Re: SI to CS alternator It's already rewired for a Internally Regulated SI alternator, And you need to rewire it (again) for a CS alternator? Your existing SI Alt. has 2 wires going to the regulator, The #1 terminal is wired to the Generator Lamp, Or a resistor wire (depending on the cluster). The #2 wire is a battery hot, Will not be used on a CS Alt. You can put a ring terminal on it & run it to the charging post, Remove it from the harness, Or Tape/heatshrink the end so it doesn't short against anything. The Generator Lamp wire will go to Pin "B" on the CS regulator plug, Some Connectors are labeled "L" (For Lamp). A Ignition Hot "MAY" need to be wired to Pin "C" on the regulator plug, Some Connectors are labeled "F" (For Field)....Most CS Alternators Do Not need this to turn on & charge, But '94 S/T trucks show it in the diagrams. Attached Images

04-18-2015, 12:01 AM	#14
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,705	Re: SI to CS alternator Maybe this will help you. http://67-72chevytrucks.com/vboard/s...d.php?t=567472 __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

04-18-2015, 08:05 AM	#15
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,217	Re: SI to CS alternator XIV. Multiple Posting - It is simply not acceptable to post your question more than once, or to post it in more than one forum. Choose the forum that your question or post best fits in, and place it there and only there. If, after posting, you feel it should be in another forum, private message the forum Moderator and ask if they would move it for you. your threads have been merged __________________ David fuller Ase Certified Mechanic Click here to help support our board!! 1971 Chevy c-10 under going a 4.8l LSx swap Build Thread http://67-72chevytrucks.com/vboard/s...d.php?t=421305 2007 Honda Accord my daily 145kmiles 2002 Honda Accord 4 door With 330k(sisters car) 2005 toyota Avalon 228k( brothers car) 2002 Sububran 5.3 245k 2000 Tahoe 5.3l 378 General manager for Marco's Carwash & lube



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