Electrical Issues - The 1947 - Present Chevrolet & GMC Truck Message Board Network

bsstb · 01-09-2009, 05:09 PM

I'm probably like every one else that has posted somthing about electrical issues on their trucks. But here is my problem. if i let my truck sit over night the battery goes dead. I've replaced the Battery, Alternator, and Voltage regulator. I have done a load check on my mutimeter and the alternator shows a draw of .33 amps. I have also taken out every fuse out to isolate the problem and couldn't find anything. What should be next course of action.

HELP!!!

Longhorn Man · 01-09-2009, 05:14 PM

When pulling fuses to check for the load dropping off, you also need to pull the plug on the volt reg, and the horn relay.
Does your horn work? It is common for the relay or button to stick, and someone just unplugs the horn. If the relay is energized, it'll drain the battery.

JimKshortstep4x4 · 01-09-2009, 08:42 PM

Did you unplug the alternator to see if the draw goes away? If the exciter wire is switched with the sensing wire on the 10-SI alternator that is the approximate draw that you will get.

Jim

Jim

sbrad701 · 01-09-2009, 08:54 PM

I had the same problem and it ended up being what JimK said. Happened right after I installed new harness so I was kinda disappointed with myself.

It turned out good in the end tho lol. Good luck.

bsstb · 01-09-2009, 09:53 PM

Jim,
Thanks for the info, I will try it tomarrow morning and see if that works.

**VetteVet** · 01-09-2009, 10:22 PM

I gathered from your first post that you have an external regulator since you changed it along with the alternator, so I don't think the wire reversal is the issue. I lean with Andy on the horn relay or another amperage draw on a circuit that is hot all the time.
It would help if you could give some details on what year truck you have and what you may have done to it, like new wiring harness or other work.

bsstb · 01-09-2009, 11:00 PM

Vette, you are right that I have an external regulator. the truck is a 67, the only real thing that i have done to the wiring is replaced the ignition switch pig tail to clean up from the previous owners electrical work. I do have a wiring diagram, every thing that it show seems to be right, as for what the diagram shows. As for that that is all that I know

**jaros44sr** · 01-09-2009, 11:04 PM

Is it a single wire alt.?

Longhorn Man · 01-09-2009, 11:06 PM

It's a stock, externally regulated 3 wire 1967 set up.

that was why I said unplug it at the regulator on the testing. Even with the new unit, it can still be defective... but if your horn doesn't work, i would zero in on it first. The relay is a rectangle silver can bolted to the firewall under the dash by the fuse box. Should have 3 wires going to it in one plug... a red and green wire, and I can't remember the color of the 3rd one. If you unplug it and it clicks, then you found the issue.

**jaros44sr** · 01-09-2009, 11:17 PM

Quote:

Originally Posted by Longhorn Man

It's a stock, externally regulated 3 wire 1967 set up.

that was why I said unplug it at the regulator on the testing. Even with the new unit, it can still be defective... but if your horn doesn't work, i would zero in on it first. The relay is a rectangle silver can bolted to the firewall under the dash by the fuse box. Should have 3 wires going to it in one plug... a red and green wire, and I can't remember the color of the 3rd one. If you unplug it and it clicks, then you found the issue.

Ahhh, just reread original post, missed the regulator part. Thanks, seems like the eyes read it these days, but the brain doesn't comprehend...

01-09-2009, 05:09 PM	#1
bsstb Registered User Join Date: Jan 2009 Location: Amarillo, Texas Posts: 11	Electrical Issues I'm probably like every one else that has posted somthing about electrical issues on their trucks. But here is my problem. if i let my truck sit over night the battery goes dead. I've replaced the Battery, Alternator, and Voltage regulator. I have done a load check on my mutimeter and the alternator shows a draw of .33 amps. I have also taken out every fuse out to isolate the problem and couldn't find anything. What should be next course of action. HELP!!!

01-09-2009, 05:14 PM	#2
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Electrical Issues When pulling fuses to check for the load dropping off, you also need to pull the plug on the volt reg, and the horn relay. Does your horn work? It is common for the relay or button to stick, and someone just unplugs the horn. If the relay is energized, it'll drain the battery.

01-09-2009, 08:42 PM	#3
JimKshortstep4x4 Senior Member Join Date: Jul 2001 Location: Muskegon,MI,USA Posts: 6,026	Re: Electrical Issues Did you unplug the alternator to see if the draw goes away? If the exciter wire is switched with the sensing wire on the 10-SI alternator that is the approximate draw that you will get. Jim Jim __________________ 1971 Shortbox step side 4x4, 350 sbc, 3:07 rear end 1965 Impala SS 400 sbc, Muncie rock crusher 1966 Impala SS 396 bbc, TH 400 1969 El Camino, 350 sbc, TH 350 1971 Snowplow built on a Blazer frame 1972 GMC Short bed, stepside, TH 400, 427 BBC

01-09-2009, 08:54 PM	#4
sbrad701 Registered User Join Date: Mar 2005 Location: Graham, NC Posts: 23	Re: Electrical Issues I had the same problem and it ended up being what JimK said. Happened right after I installed new harness so I was kinda disappointed with myself. It turned out good in the end tho lol. Good luck.

01-09-2009, 09:53 PM	#5
bsstb Registered User Join Date: Jan 2009 Location: Amarillo, Texas Posts: 11	Re: Electrical Issues Jim, Thanks for the info, I will try it tomarrow morning and see if that works.

01-09-2009, 10:22 PM	#6
VetteVet Msgt USAF Ret Join Date: Jan 2005 Location: Kalamazoo, Michigan Posts: 8,717	Re: Electrical Issues I gathered from your first post that you have an external regulator since you changed it along with the alternator, so I don't think the wire reversal is the issue. I lean with Andy on the horn relay or another amperage draw on a circuit that is hot all the time. It would help if you could give some details on what year truck you have and what you may have done to it, like new wiring harness or other work. __________________ VetteVet metallic green 67 stepside 74 corvette convertible 1965 Harley sportster 1995 Harley wide glide Growing old is hell, but it beats the alternative.

01-09-2009, 11:00 PM	#7
bsstb Registered User Join Date: Jan 2009 Location: Amarillo, Texas Posts: 11	Re: Electrical Issues Vette, you are right that I have an external regulator. the truck is a 67, the only real thing that i have done to the wiring is replaced the ignition switch pig tail to clean up from the previous owners electrical work. I do have a wiring diagram, every thing that it show seems to be right, as for what the diagram shows. As for that that is all that I know

01-09-2009, 11:04 PM	#8
jaros44sr Senior Member Join Date: May 2006 Location: Philadelphia, Pa. 19454 Posts: 9,694	Re: Electrical Issues Is it a single wire alt.? __________________ Semper Fi...Uncle Sam, you da man All parts offered to help are free, unless otherwise noted Dont try this stuff in my build thread, unless you have 55 years of mechanical OTJ training SAFETY FIRST AS usual, off topic They say your mind goes second, can't remember the first Jim

01-09-2009, 11:06 PM	#9
Longhorn Man its all about the +6 inches Join Date: Jan 2001 Location: Hilliard Ohio Posts: 2,693	Re: Electrical Issues It's a stock, externally regulated 3 wire 1967 set up. that was why I said unplug it at the regulator on the testing. Even with the new unit, it can still be defective... but if your horn doesn't work, i would zero in on it first. The relay is a rectangle silver can bolted to the firewall under the dash by the fuse box. Should have 3 wires going to it in one plug... a red and green wire, and I can't remember the color of the 3rd one. If you unplug it and it clicks, then you found the issue. Last edited by Longhorn Man; 01-09-2009 at 11:06 PM.



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