Still having wiring problems please help - The 1947 - Present Chevrolet & GMC Truck Message Board Network

J · 11-19-2005, 02:47 PM

Ok I'm on my second NAPA Orbital battery. First one died and wouldn't charge. They replaced it free and now the new one is having the same problem. I think the alternator may be wired wrong. I asked a few weeks back about hooking up the pigtail. The answer was run the red wire as a jumper and then to the battery. Did that. Then run the white wire to the brown wire on the voltage regulator. Did that too. Truck ran fine. I let her sit for a week and now the battery is dead as can be, and when I hook it up to the charger the red fault light comes on and it won't charge (same as the first battery).

Am I missing something here? Did I hook it up wrong? The truck was set up with a Summit one wire alternator for years and worked fine like that. Now I have a new NAPA alternator with pigtail. Any help you all can give would be greatly apperciated. Thanks in advance.

Jeff

dwaite72lnghrn · 11-19-2005, 03:59 PM

If it is an "SI" alternator this is how it should be hooked up(running in my '71 GMC). If it is the "CS" style then the bottom hookup (Running in my '72). If the GIF files come out in the correct order.

J · 11-19-2005, 07:18 PM

How do I know if its a SI or CS alternator? After digging around a bit in the old wiring I found blue and white wire leads running into voltage regulator. Probably when snipped off when the one wire alternator was installed.

I have one red and one white wire on the pigtail can't figure which is 1 and which is 2 (on the diagram)?

Thanks for your help. I need to get this done and done right since I don't think NAPA is gonna be pleased with me bringing back another battery.

*bisquik65* · 11-19-2005, 07:24 PM

Check right behind the drivers side headlight on the wire harness for a (small bulge) in the harness,twist this open...there is the charging system fuse in there,A small glass fuse,If its blown,it will not charge....You will find it pretty easy...And its may on the pass side depending on what year your truck is..

chevymad · 11-19-2005, 07:52 PM

Make sure you don't have a draw too. Take your battery cable loose and hook a test light between it and the battery post. If the light comes on you have a draw somewhere. Pull the fuses one at a time till it goes out. If it doesnt try disconnecting the alternator. If disconnecting the alternator cures the draw you probably have a bad diode in the alternator. Optima/oribital batteries are great but they don't take to sitting dead very well. If they go dead and you don't charge them right away they'll never come back again. They also have a lower resistance and being completely dead it may be drawing too hard on your charger. You could either try another charger or hook it up to a running vehicle with a set of jumper cables for awhile. Then finish charging with your charger.

dwaite72lnghrn · 11-19-2005, 10:59 PM

Here is a picture of the CS alternator(105amp). The wire connector is opposite side from the red charge connection. I don't have a pic of the SI right now, To dark to get a good shot.

J · 11-21-2005, 09:22 PM

Ok it looks like I have an SI alternator. I guess my question now is that I have a blue wire and a white wire coming from the voltage regulator and I have a white and a red coming from the alternator. White to white and red to blue or vice versa?
Also once I have it running what should my multimeter read to let me know everything is working OK?

dwaite72lnghrn · 11-21-2005, 10:50 PM

You should have a White(18 gauge), Blue(18 gauge) and red (10-12 gauge)from the Alternator. The voltage regulator should be out of the circuit and the brown wire tied to the blue and the white to the white. This is how I have it setup and no problems on a 71 GMC.
Then take your meter to the red charging wire and see if you have 13.8volts between it and a ground with the engine running. With the engine not running you should have about 12.8volts give or take a few 10ths.

**truckdude239** · 11-22-2005, 12:03 AM

anything above 13.5 volts my 87 f-150 reads about 15 volts at all times

73stepside · 11-22-2005, 12:34 AM

you need to have the si alyernators excited to work properly ie charge. in the 2nd diagram is how i wired my 70, but i ran the white wire from the alternator connector to the brown wire and the red wire to the battery post on the alternator. i also ran a new 10 gauge wire to the battery junction block. i can give better directions or diagrams of how it was done if wanted

11-19-2005, 02:47 PM	#1
J Registered User Join Date: Oct 2001 Location: Yuma, AZ Posts: 164	Still having wiring problems please help Ok I'm on my second NAPA Orbital battery. First one died and wouldn't charge. They replaced it free and now the new one is having the same problem. I think the alternator may be wired wrong. I asked a few weeks back about hooking up the pigtail. The answer was run the red wire as a jumper and then to the battery. Did that. Then run the white wire to the brown wire on the voltage regulator. Did that too. Truck ran fine. I let her sit for a week and now the battery is dead as can be, and when I hook it up to the charger the red fault light comes on and it won't charge (same as the first battery). Am I missing something here? Did I hook it up wrong? The truck was set up with a Summit one wire alternator for years and worked fine like that. Now I have a new NAPA alternator with pigtail. Any help you all can give would be greatly apperciated. Thanks in advance. Jeff __________________ '72 C-10 '99 Silverado '91 S-Dime

11-19-2005, 03:59 PM	#2
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	Re: Still having wiring problems please help If it is an "SI" alternator this is how it should be hooked up(running in my '71 GMC). If it is the "CS" style then the bottom hookup (Running in my '72). If the GIF files come out in the correct order. Attached Images __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

11-19-2005, 07:18 PM	#3
J Registered User Join Date: Oct 2001 Location: Yuma, AZ Posts: 164	Re: Still having wiring problems please help How do I know if its a SI or CS alternator? After digging around a bit in the old wiring I found blue and white wire leads running into voltage regulator. Probably when snipped off when the one wire alternator was installed. I have one red and one white wire on the pigtail can't figure which is 1 and which is 2 (on the diagram)? Thanks for your help. I need to get this done and done right since I don't think NAPA is gonna be pleased with me bringing back another battery. __________________ '72 C-10 '99 Silverado '91 S-Dime

11-19-2005, 07:24 PM	#4
bisquik65 Account Suspended Join Date: Apr 2004 Location: N.C. high country Posts: 6,107	Re: Still having wiring problems please help Check right behind the drivers side headlight on the wire harness for a (small bulge) in the harness,twist this open...there is the charging system fuse in there,A small glass fuse,If its blown,it will not charge....You will find it pretty easy...And its may on the pass side depending on what year your truck is..

11-19-2005, 07:52 PM	#5
chevymad Registered User Join Date: Jan 2001 Location: skamokawa, WA, USA Posts: 527	Re: Still having wiring problems please help Make sure you don't have a draw too. Take your battery cable loose and hook a test light between it and the battery post. If the light comes on you have a draw somewhere. Pull the fuses one at a time till it goes out. If it doesnt try disconnecting the alternator. If disconnecting the alternator cures the draw you probably have a bad diode in the alternator. Optima/oribital batteries are great but they don't take to sitting dead very well. If they go dead and you don't charge them right away they'll never come back again. They also have a lower resistance and being completely dead it may be drawing too hard on your charger. You could either try another charger or hook it up to a running vehicle with a set of jumper cables for awhile. Then finish charging with your charger. __________________ 70 C10 long fleet, 355/200 4r, 6 lug disc conversion, 3" drop 70 gmc changed to 67/8 chevy, 454 with voodoo cam, th400, all 74 running gear.. in progress

11-19-2005, 10:59 PM	#6
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	Re: Still having wiring problems please help Here is a picture of the CS alternator(105amp). The wire connector is opposite side from the red charge connection. I don't have a pic of the SI right now, To dark to get a good shot. Attached Images __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

11-21-2005, 09:22 PM	#7
J Registered User Join Date: Oct 2001 Location: Yuma, AZ Posts: 164	Re: Still having wiring problems please help Ok it looks like I have an SI alternator. I guess my question now is that I have a blue wire and a white wire coming from the voltage regulator and I have a white and a red coming from the alternator. White to white and red to blue or vice versa? Also once I have it running what should my multimeter read to let me know everything is working OK? __________________ '72 C-10 '99 Silverado '91 S-Dime

11-21-2005, 10:50 PM	#8
dwaite72lnghrn Registered User Join Date: Jun 2002 Location: central pa Posts: 1,525	Re: Still having wiring problems please help You should have a White(18 gauge), Blue(18 gauge) and red (10-12 gauge)from the Alternator. The voltage regulator should be out of the circuit and the brown wire tied to the blue and the white to the white. This is how I have it setup and no problems on a 71 GMC. Then take your meter to the red charging wire and see if you have 13.8volts between it and a ground with the engine running. With the engine not running you should have about 12.8volts give or take a few 10ths. __________________ 72 longhorn c30 502BB/th400/fact air/4.11rear/ custom camper 72 bug(the better half's) under reconstruction 2009 HHR aqua blue 71 GMC k20 350/sm465 2009 Chevy hd3500 6.6 Victory Red crew cab dually Dave & Jeanne

11-22-2005, 12:03 AM	#9
truckdude239 Senior Member Join Date: Sep 2005 Location: Lewisville, Nc Posts: 10,233	Re: Still having wiring problems please help anything above 13.5 volts my 87 f-150 reads about 15 volts at all times __________________ 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

11-22-2005, 12:34 AM	#10
73stepside Registered User Join Date: Feb 2002 Location: Moore OK 73160 Posts: 974	Re: Still having wiring problems please help you need to have the si alyernators excited to work properly ie charge. in the 2nd diagram is how i wired my 70, but i ran the white wire from the alternator connector to the brown wire and the red wire to the battery post on the alternator. i also ran a new 10 gauge wire to the battery junction block. i can give better directions or diagrams of how it was done if wanted __________________ 04 GMC Sierra RCSS 70 CST LWB 04 HD Sportster 1200 Custom



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