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

big.l.a · 11-19-2002, 01:11 AM

Anybody got any suggestion on what could cause the battery to go dead on my buddies 68 C10 . replaced the Inside wire harness..... after 2 day the battery Is completely dead....

Longhorn Man · 11-19-2002, 01:14 AM

If the altenater is working, and the voltage regulater is working, then there is something draining the battery through the night.
Has anything just been installed? A stereo amp maybe?

big.l.a · 11-19-2002, 01:53 AM

Can't I by pass the voltage regulator since In has HEI??? and a
1 wire Alternator?????

BUXMAN66 · 11-19-2002, 02:18 AM

i've been encountering the same problem and i think i've finally found my solution.grounding straps. both of them.the one from the engine block or head, to the cab and also the one from the frame to the body.the alt. is is putting out the needed voltage(by bench testing at your patrs store) but the voltage is not being returned to the battery to keep it charged because the ground is not being completed because of broken or brittle or just plain unhooked ground straps.i would begin there.this is all providing that you have checked both your alt.and your battery are okay.hope this helps some!later .

big.l.a · 11-19-2002, 08:01 AM

Wow I look right @ the ground straps and didn't think that could be the problem, because they are unhooked from the engine
replacement..... Thanks alot I hope this works

Longhorn Man · 11-20-2002, 12:51 AM

Was the alt just installed when the problem started?
Yes, it would be a good idea to bypass the external regulater. It is just in the way now.

big.l.a · 11-20-2002, 08:49 AM

This Is a friend of mine's truck(68). He had a 350 Installed In it
an let it set for a year a now he want to restore it after seeing my truck. I did find the the ground straps were not hooked up.
The Engine was freshly rebuilt never been on the road.....
everything looks new......... I will get out my meter and check the
out put volts from the alternator........

ah_5500 · 11-25-2010, 12:10 AM

Bringing back an old thread I guess but just wondering how to determine if I can unhook the voltage regulator since I put hei on my truck. Becaue I'm having battery trouble as well?
Posted via Mobile Device

Jacfourteen · 11-25-2010, 01:52 AM

HEI has no effect on if you need an external regulator or not. What determines this is if the Alternator has a regulator inside the housing (internally regulated), or if it has no regulator inside the housing (needs a regulator wired in somewhere else in the system, so caller external regulator). A little more detail is needed to help you out with you battery trouble.

BigPhil66 · 12-04-2010, 08:44 PM

How would one know if the ltenator has a regulator built in?

**VetteVet** · 12-05-2010, 12:31 AM

The external regulator alternator is low amperage and the plastic plug goes into the rear of the alternator whereas the internal alternator plastic plug goes into the topside.

Name: GmAlternatorIdentification.jpg
Views: 116
Size: 26.5 KB

Name: GmAlternatorIdentification.jpg
Views: 116
Size: 26.5 KB

Your drain is not the ground wires unless one of them is shorting on a live wire or terminal. If that were the case you would have a much larger current draw.

BigPhil66 · 12-05-2010, 12:45 AM

Thanks for the pic, I blieve mine is the one on the left but I don't see the regulator anywhere in the engine bay. there is two wires going to the positive and one small wire going to the firewall (I assume it goes to the dash meter.) There also appears to be a another post for a groun on the altenator on the right of the altenator.

**VetteVet** · 12-05-2010, 01:38 AM

The regulator is mounted on the drivers side of the radiator support by the horn. See post 6 it's the black box under the jumper wires. I don't want to get into much more because we are hi-jacking Big l.a.'s thread. If you want to start a new thread in the electrical forum we will get in depth on your problem. I'm going to post a link to the FAQS on finding a key off drain for BIG l.A..

**VetteVet** · 12-05-2010, 02:11 AM

In order to find a key off drain you need to isolate the circuit that is drawing battery power. It will most likely be a circuit that is powered directly from the battery, not from the fuse box unless the fuse is hot with the key off.

Disconnect the negative battery cable and connect a test light between the cable and the battery post. Start pulling fuses and watch to see if the light goes out. If it does then the draw is in that circuit. Examples are, the horn relay. If the horn is disconnected you won't hear it blow, but the relay will be energized and drawing juice. That might be caused by the horn wire in the steering column touching a ground. Any light that comes on without the key, dome light, glove box, heater control light, cigarette lighter, brake lights, a short in the light switch, or any aftermarket device not wired off the fuse box.

Another favorite is the diode in the alternator. Disconnect the wires to it and see if the test light goes out. Having the two small wires reversed in the plastic plug on the alternator will also drain the battery.

Here is a website with some more great information.
http://www.aa1car.com/library/battery_runs_down.htm

BigPhil66 · 12-05-2010, 02:12 AM

Thanks....Sorry Big l.a

Longhorn Man · 12-05-2010, 11:33 AM

this thread is 8 years old, i doubt anyone's toes were stepped on

Legolas894 · 12-05-2010, 08:35 PM

Voltage regulator is under the washer fluid bottle if you still have that. The key-off drain is the most common problem. See the electrical forum for lots of good advice.

11-19-2002, 01:11 AM	#1
big.l.a Registered User Join Date: Jan 2002 Location: Allen, TX. USA Posts: 210	Dead Battery Delima Anybody got any suggestion on what could cause the battery to go dead on my buddies 68 C10 . replaced the Inside wire harness..... after 2 day the battery Is completely dead.... __________________ 71 C10 LWB With Edelbrock 7101& 1406 Carb Accel HEI Blue Print Accel 8.8 Wires Soon to have possi & 186 Camel hump heads Dropped 2-1/2F&4R Dynomax Headers Duals Flowtech Aftburners Tonneau Cover Frm 89 F150 79 Monte C

11-19-2002, 01:53 AM	#3
big.l.a Registered User Join Date: Jan 2002 Location: Allen, TX. USA Posts: 210	dead battery Can't I by pass the voltage regulator since In has HEI??? and a 1 wire Alternator????? __________________ 71 C10 LWB With Edelbrock 7101& 1406 Carb Accel HEI Blue Print Accel 8.8 Wires Soon to have possi & 186 Camel hump heads Dropped 2-1/2F&4R Dynomax Headers Duals Flowtech Aftburners Tonneau Cover Frm 89 F150 79 Monte C

11-19-2002, 08:01 AM	#5
big.l.a Registered User Join Date: Jan 2002 Location: Allen, TX. USA Posts: 210	dead battery Wow I look right @ the ground straps and didn't think that could be the problem, because they are unhooked from the engine replacement..... Thanks alot I hope this works __________________ 71 C10 LWB With Edelbrock 7101& 1406 Carb Accel HEI Blue Print Accel 8.8 Wires Soon to have possi & 186 Camel hump heads Dropped 2-1/2F&4R Dynomax Headers Duals Flowtech Aftburners Tonneau Cover Frm 89 F150 79 Monte C

11-20-2002, 12:51 AM	#6
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Was the alt just installed when the problem started? Yes, it would be a good idea to bypass the external regulater. It is just in the way now. Attached Images

11-20-2002, 08:49 AM	#7
big.l.a Registered User Join Date: Jan 2002 Location: Allen, TX. USA Posts: 210	Dead battery This Is a friend of mine's truck(68). He had a 350 Installed In it an let it set for a year a now he want to restore it after seeing my truck. I did find the the ground straps were not hooked up. The Engine was freshly rebuilt never been on the road..... everything looks new......... I will get out my meter and check the out put volts from the alternator........ __________________ 71 C10 LWB With Edelbrock 7101& 1406 Carb Accel HEI Blue Print Accel 8.8 Wires Soon to have possi & 186 Camel hump heads Dropped 2-1/2F&4R Dynomax Headers Duals Flowtech Aftburners Tonneau Cover Frm 89 F150 79 Monte C

11-19-2002, 01:14 AM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	If the altenater is working, and the voltage regulater is working, then there is something draining the battery through the night. Has anything just been installed? A stereo amp maybe?

11-19-2002, 02:18 AM	#4
BUXMAN66 go bucks! Join Date: Jan 2002 Location: MIAMISBURG OHIO USA Posts: 803	i've been encountering the same problem and i think i've finally found my solution.grounding straps. both of them.the one from the engine block or head, to the cab and also the one from the frame to the body.the alt. is is putting out the needed voltage(by bench testing at your patrs store) but the voltage is not being returned to the battery to keep it charged because the ground is not being completed because of broken or brittle or just plain unhooked ground straps.i would begin there.this is all providing that you have checked both your alt.and your battery are okay.hope this helps some!later .

11-25-2010, 12:10 AM	#8
ah_5500 Registered User Join Date: Nov 2008 Location: knoxville, tn Posts: 155	Re: Dead Battery Delima Bringing back an old thread I guess but just wondering how to determine if I can unhook the voltage regulator since I put hei on my truck. Becaue I'm having battery trouble as well? Posted via Mobile Device

11-25-2010, 01:52 AM	#9
Jacfourteen Big Red - Now its a SWB! Join Date: Jun 2009 Location: Oroville, Ca Posts: 1,624	Re: Dead Battery Delima HEI has no effect on if you need an external regulator or not. What determines this is if the Alternator has a regulator inside the housing (internally regulated), or if it has no regulator inside the housing (needs a regulator wired in somewhere else in the system, so caller external regulator). A little more detail is needed to help you out with you battery trouble. __________________ 68 3/4 ton (Project)-350 Small Block, .030 over, 10:1 comp, 3998993 heads, C3BX edelbrock intake, comp cams XE268, Holley 670 SA, long tube headers, dual flow 40's, E-fan, Alum rad, currently under the knife getting shortened and bagged build thread 41 3/4 ton (wife's)-flatbed, fully restored to original 01 Tahoe LT 4WD (my daily driver)-Magnaflow Muffler, Rollin on 22's 02 Ford Mustang Convertable (Wife's Car)-Flowmaster 50, Clear corners, Intake, sittin on 18's Last edited by Jacfourteen; 11-25-2010 at 01:53 AM.

12-04-2010, 08:44 PM	#10
BigPhil66 Registered User Join Date: Aug 2010 Location: Riverside Ca. Posts: 47	Re: Dead Battery Delima How would one know if the ltenator has a regulator built in?

12-05-2010, 12:31 AM	#11
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: Dead Battery Delima The external regulator alternator is low amperage and the plastic plug goes into the rear of the alternator whereas the internal alternator plastic plug goes into the topside. Your drain is not the ground wires unless one of them is shorting on a live wire or terminal. If that were the case you would have a much larger current draw. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

12-05-2010, 12:45 AM	#12
BigPhil66 Registered User Join Date: Aug 2010 Location: Riverside Ca. Posts: 47	Re: Dead Battery Delima Thanks for the pic, I blieve mine is the one on the left but I don't see the regulator anywhere in the engine bay. there is two wires going to the positive and one small wire going to the firewall (I assume it goes to the dash meter.) There also appears to be a another post for a groun on the altenator on the right of the altenator.

12-05-2010, 01:38 AM	#13
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: Dead Battery Delima The regulator is mounted on the drivers side of the radiator support by the horn. See post 6 it's the black box under the jumper wires. I don't want to get into much more because we are hi-jacking Big l.a.'s thread. If you want to start a new thread in the electrical forum we will get in depth on your problem. I'm going to post a link to the FAQS on finding a key off drain for BIG l.A.. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

12-05-2010, 02:11 AM	#14
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: Dead Battery Delima In order to find a key off drain you need to isolate the circuit that is drawing battery power. It will most likely be a circuit that is powered directly from the battery, not from the fuse box unless the fuse is hot with the key off. Disconnect the negative battery cable and connect a test light between the cable and the battery post. Start pulling fuses and watch to see if the light goes out. If it does then the draw is in that circuit. Examples are, the horn relay. If the horn is disconnected you won't hear it blow, but the relay will be energized and drawing juice. That might be caused by the horn wire in the steering column touching a ground. Any light that comes on without the key, dome light, glove box, heater control light, cigarette lighter, brake lights, a short in the light switch, or any aftermarket device not wired off the fuse box. Another favorite is the diode in the alternator. Disconnect the wires to it and see if the test light goes out. Having the two small wires reversed in the plastic plug on the alternator will also drain the battery. Here is a website with some more great information. http://www.aa1car.com/library/battery_runs_down.htm __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative. Last edited by VetteVet; 12-05-2010 at 02:14 AM.

12-05-2010, 02:12 AM	#15
BigPhil66 Registered User Join Date: Aug 2010 Location: Riverside Ca. Posts: 47	Re: Dead Battery Delima Thanks....Sorry Big l.a



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12-05-2010, 11:33 AM	#16
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Dead Battery Delima this thread is 8 years old, i doubt anyone's toes were stepped on

12-05-2010, 08:35 PM	#17
Legolas894 Chemist under the hood... Join Date: Apr 2009 Location: Fort Erie,ON, Canada Posts: 617	Re: Dead Battery Delima Voltage regulator is under the washer fluid bottle if you still have that. The key-off drain is the most common problem. See the electrical forum for lots of good advice. __________________ Current fleet: 2013 GMC Sierra, 5.3L, 4x4 1988 GMC Sierra, 305, Auto 1984 Jeep Grand Wagoneer, 360 V8 1997 VW Cabrio, 2.0L 2017 Toyota Rav4, 2.5L Stuff I wish I still had: 2013 Toyota Matrix [RIP] 1967 GMC 910 Fleetside, 283 V8 [1st Love-SOLD] 1987 Jeep Cherokee Laredo 4X4, 4.0 I-6 [SOLD} 1994 Chevrolet Caprice Classic, 5.7LV8 [SOLD] 1995 Chevrolet Astro AWD, 4.3L V6 (RIP) 1998 Chevrolet Suburban 4x4, 5.7L V8 [SOLD]

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