Battery Voltage - The 1947 - Present Chevrolet & GMC Truck Message Board Network

**53burb** · 08-30-2004, 11:46 AM

I know we have gone over this before, but what should the voltage at the battery be while it is running or not running?? I read 12.5 volts running or not. The alternator was reading 12.5 also at the battery terminal. Shouldn't it read 14.5 volts?? Is it different with an external regulator?? It is a 350 with an externally regulated alternator??
Thanks...
Chris

JimKshortstep4x4 · 08-30-2004, 11:56 AM

With the engine running you should be getting 14.5 volts at approx. 1200 rpm.

If you don't get 14.5 approximately then your regulator could just need adjusting. I know the internally regulated alternators have some advantages but externaly regulators do work and some of my vehicles still have the external regulator.

I can fax you the instructions for adjusting the regulator if you like.

Jim

**53burb** · 08-30-2004, 12:24 PM

Pleae fax me the instructions @ 480-715-9009...If it only needs adjusting thats fine, if it needs replacing, then I will swap to an internally regulated alternator. I do believe the alternator is on its way out. I can hear it when the engine is running at idle.

Longhorn Man · 08-30-2004, 03:24 PM

Chances are, the regulator or alt is dead. The regulator is a very cheap part...like 12 bucks or something...but personally, I'd go and spend the 12 bucks at the junk yard for a later internally regulated deal.

**53burb** · 08-30-2004, 07:09 PM

Thanks for the answers. I know that there is someone that did this swap by connecting some wires at the plug into the regulator and not using one. Does anybody have that link??

JimKshortstep4x4 · 08-30-2004, 08:13 PM

Did you get the faxed instructions on the regulator? My Fax machine indicated that it went through.

Jim

68w/sbc406 · 08-30-2004, 08:30 PM

down at the plug to the regulator i hooked the brown and blue together and left the red and white pluged in. also had to run a bigger wire from the alternator to the battery but i did some rewiring so it might have been because of that.

**53burb** · 08-31-2004, 10:55 AM

I did receive the fax. I stopped by Checkers yesterday, they confirmed that there is a problem with the charging system. According to the PO, the alternator has been replaced within the last few years. It may be the regulator. However, I am going to replace both units with an internally regulated unit.

**53burb** · 08-31-2004, 07:41 PM

I didn't have time to finish my post earlier. But anyways, thanks for the replys and the fax...
Chris

08-30-2004, 11:46 AM	#1
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,010	Battery Voltage I know we have gone over this before, but what should the voltage at the battery be while it is running or not running?? I read 12.5 volts running or not. The alternator was reading 12.5 also at the battery terminal. Shouldn't it read 14.5 volts?? Is it different with an external regulator?? It is a 350 with an externally regulated alternator?? Thanks... Chris

08-30-2004, 08:30 PM	#7
68w/sbc406 Got Light Emitting Diode? Join Date: Apr 2004 Location: Newberg, OR Posts: 2,485	down at the plug to the regulator i hooked the brown and blue together and left the red and white pluged in. also had to run a bigger wire from the alternator to the battery but i did some rewiring so it might have been because of that. __________________ 1968 1/2 ton 2wd lwb 6 lug disc and bags up front. Next c notch and rear bags '02 Chevy Silverado LT ext cab short bed 2WD 5/7 drop on 22's(the family car) 1993 Cherokee work ride/weekend wheeler

08-30-2004, 11:56 AM	#2
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	With the engine running you should be getting 14.5 volts at approx. 1200 rpm. If you don't get 14.5 approximately then your regulator could just need adjusting. I know the internally regulated alternators have some advantages but externaly regulators do work and some of my vehicles still have the external regulator. I can fax you the instructions for adjusting the regulator if you like. Jim

08-30-2004, 12:24 PM	#3
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,010	Pleae fax me the instructions @ 480-715-9009...If it only needs adjusting thats fine, if it needs replacing, then I will swap to an internally regulated alternator. I do believe the alternator is on its way out. I can hear it when the engine is running at idle.

08-30-2004, 03:24 PM	#4
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,690	Chances are, the regulator or alt is dead. The regulator is a very cheap part...like 12 bucks or something...but personally, I'd go and spend the 12 bucks at the junk yard for a later internally regulated deal.

08-30-2004, 07:09 PM	#5
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,010	Thanks for the answers. I know that there is someone that did this swap by connecting some wires at the plug into the regulator and not using one. Does anybody have that link??

08-30-2004, 08:13 PM	#6
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Did you get the faxed instructions on the regulator? My Fax machine indicated that it went through. Jim

08-31-2004, 10:55 AM	#8
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,010	I did receive the fax. I stopped by Checkers yesterday, they confirmed that there is a problem with the charging system. According to the PO, the alternator has been replaced within the last few years. It may be the regulator. However, I am going to replace both units with an internally regulated unit.

08-31-2004, 07:41 PM	#9
53burb Senior Member Join Date: May 2004 Location: Queen Creek, AZ Posts: 1,010	I didn't have time to finish my post earlier. But anyways, thanks for the replys and the fax... Chris



Register or Log In To remove these advertisements.

Register or Log In To remove these advertisements.