The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > 47 - Current classic GM Trucks > The 1967 - 1972 Chevrolet & GMC Pickups Message Board

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 01-13-2018, 12:04 AM   #1
71C10Guy
Registered User
 
Join Date: Jul 2017
Location: Dripping Springs
Posts: 20
Angry Wiring problems before inspection

So about a week ago my blinkers, wipers, blower motor, reverse lights, and brake lights all went out at once. I have no explanation for it, but now my alternator only seems to kick on after I use my blinker, which also makes my brake lights go off on whatever side I turned my blinker to. Is there a central fuse for accessories behind the main panel or something? Or any kind of explanation of this all happening at once after a year and a half of the truck being back on the road?
Btw the previous owner had all kinds of aftermarket electronic stuff on the truck that my dad and I ripped out without discretion, so the entire truck is basically just a giant ball of ubconnected and stripped wires. Also what's left of the original wiring harness is spliced into so many times it might as well be a tree. There are splices on top of splices on top of splices on some of the wires. I know this will just take time to sort out or a new wiring harness. My question is possible reasons for multiple systems going out all at once?
71C10Guy is offline   Reply With Quote
Old 01-13-2018, 12:43 AM   #2
LockDoc
The Original Thread Killer

 
LockDoc's Avatar
 
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 17,390
Re: Wiring problems before inspection

Quote:
Originally Posted by 71C10Guy View Post
So about a week ago my blinkers, wipers, blower motor, reverse lights, and brake lights all went out at once. I have no explanation for it, but now my alternator only seems to kick on after I use my blinker, which also makes my brake lights go off on whatever side I turned my blinker to. Is there a central fuse for accessories behind the main panel or something? Or any kind of explanation of this all happening at once after a year and a half of the truck being back on the road?
Btw the previous owner had all kinds of aftermarket electronic stuff on the truck that my dad and I ripped out without discretion, so the entire truck is basically just a giant ball of ubconnected and stripped wires. Also what's left of the original wiring harness is spliced into so many times it might as well be a tree. There are splices on top of splices on top of splices on some of the wires. I know this will just take time to sort out or a new wiring harness. My question is possible reasons for multiple systems going out all at once?

It's really hard telling what is going on with all of the problems you have, and the wiring being messed up like it is. I would just replace the under dash wire loom with a good stock one to start with. It really isn't as hard as it appears and it will give you a clean slate to start with. Just make sure you get one from a truck with the same type instrument cluster you have, and same transmission, & AC/NON AC. Also make sure the fuse holders are not rusted which is common.

LockDoc
__________________
Leon

Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles
LockDoc is offline   Reply With Quote
Old 01-13-2018, 12:46 AM   #3
71C10Guy
Registered User
 
Join Date: Jul 2017
Location: Dripping Springs
Posts: 20
Re: Wiring problems before inspection

Quote:
Originally Posted by LockDoc View Post
It's really hard telling what is going on with all of the problems you have, and the wiring being messed up like it is. I would just replace the under dash wire loom with a good stock one to start with. It really isn't as hard as it appears and it will give you a clean slate to start with. Just make sure you get one from a truck with the same type instrument cluster you have, and same transmission, AC/NON AC.

LockDoc
Sounds about right. I was really just wondering if there was one fuse that controls the accessories or a circuit or relay, really anything that most of these tie into. Really hoping for a hidden fuse behind the fuse panel? Please?
71C10Guy is offline   Reply With Quote
Old 01-13-2018, 01:21 AM   #4
kwmech
Senior Member
 
Join Date: Mar 2003
Location: Colfax-California
Posts: 4,862
Re: Wiring problems before inspection

Sounds like the majority of the circuits are ignition circuits not battery. Take a look at the back side of the ignition switch plug for melted wires
kwmech is offline   Reply With Quote
Old 01-13-2018, 09:52 AM   #5
bigmac73
Senior Member
 
Join Date: Mar 2012
Location: chesapeake, Va
Posts: 881
Re: Wiring problems before inspection

I would just replace the whole harness including g fuse box with new and start fresh , would not want to deal with a electrical fire under the dash while driving
__________________
Mike
72 C-10 Cheyenne PS/PB/Tilt/Tach/Rear slider/
385HP/420TQ Vortec 355 /TH350 2200RPM Stall
MSD Ignition/Holley 650 DP/3:73 gear Eaton Limited Slip unit / 2 1/2 exhaust glasspacks
bigmac73 is offline   Reply With Quote
Old 01-13-2018, 10:31 AM   #6
Andy4639
Orignal Goof member
 
Andy4639's Avatar
 
Join Date: Jan 2002
Location: Liberty, & Garden City S.C. , U.S.
Posts: 16,091
Thumbs up Re: Wiring problems before inspection

The turn signal switch will turn the brake light off on which ever side the turn signal is on. It's controlled by the turn signal switch. This is normal. The alternator coming on isn't though.

Look at the fuses and make sure they all are good and working when power is on. These trucks are bad about the fuses getting rusty and not making contact even in the holders correctly.
As far as the wiring problems that a personal choice.
Here is a link that shows the correct color wiring. You can figure the wires out from here.


http://67-72chevytrucks.com/vboard/s...185856&page=16
__________________
1971 LWB Custom, 6.0LS & 4L80E, Speedhut.com GPS speedometer & gauges with A/C. 20" Boss 338's Grey wheels 4 wheel disc brakes. My Driver
Seeing the USA in a 71


Upstate SC GM Truck Club
2013,14 and 2016 Hot Rod Pour Tour


http://upstategmtrucks.com/



Get out and drive the truck this summer and have some fun!
It sucks not being able to hear!

LWB trucks rule, if you don't think so measure your SWB!
After talking to tech support at Air Lift I have found out that the kit I need is 60811. Per the measurements I gave them. Ride height of truck inside spring and inside diameter of springs.
Andy4639 is offline   Reply With Quote
Old 01-13-2018, 10:53 AM   #7
twouvakind
Member non 5 MPH Bumper Club
 
twouvakind's Avatar
 
Join Date: Dec 2011
Location: New Jersey
Posts: 2,453
Re: Wiring problems before inspection

You already know this but...don't lose your investment to fire.

https://sca.auction/en/21479599-1972-chevrolet-c10

Quote:
Originally Posted by 71C10Guy View Post
So about a week ago my blinkers, wipers, blower motor, reverse lights, and brake lights all went out at once. I have no explanation for it, but now my alternator only seems to kick on after I use my blinker, which also makes my brake lights go off on whatever side I turned my blinker to. Is there a central fuse for accessories behind the main panel or something? Or any kind of explanation of this all happening at once after a year and a half of the truck being back on the road?
Btw the previous owner had all kinds of aftermarket electronic stuff on the truck that my dad and I ripped out without discretion, so the entire truck is basically just a giant ball of ubconnected and stripped wires. Also what's left of the original wiring harness is spliced into so many times it might as well be a tree. There are splices on top of splices on top of splices on some of the wires. I know this will just take time to sort out or a new wiring harness. My question is possible reasons for multiple systems going out all at once?

Last edited by twouvakind; 01-13-2018 at 11:01 AM. Reason: link
twouvakind is offline   Reply With Quote
Old 01-13-2018, 02:56 PM   #8
VetteVet
Msgt USAF Ret
 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 7,880
Re: Wiring problems before inspection

On the back of the ignition switch is a 12 gauge brown wire that powers all of your accessories. This wire may not be connected any longer (open) to the fuse panel. There is no fuse for this wire or any behind the fuse panel. All the circuits it powers are fused separately.

The wire is pointed out by the black arrows. Notice also that the small tan striped wire that connects with it at the key switch is the exciter wire for the alternator and it is probably open as well. This is probably why your alternator is not charging until you rev up the engine. This is a resistance wire (10 ohms) and is needed to protect the diode trio in the alternator, so you need to get it working.

Name:  Cab-2-web.jpg
Views: 110
Size:  104.5 KB



This is the wire at the fuse panel powering all the fuses for the things that aren't working.

Name:  Cab-1web.jpg
Views: 109
Size:  101.1 KB
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 01-14-2018, 12:34 AM   #9
LockDoc
The Original Thread Killer

 
LockDoc's Avatar
 
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 17,390
Re: Wiring problems before inspection

Quote:
Originally Posted by VetteVet View Post
On the back of the ignition switch is a 12 gauge brown wire that powers all of your accessories. This wire may not be connected any longer (open) to the fuse panel. There is no fuse for this wire or any behind the fuse panel. All the circuits it powers are fused separately.

The wire is pointed out by the black arrows. Notice also that the small tan striped wire that connects with it at the key switch is the exciter wire for the alternator and it is probably open as well. This is probably why your alternator is not charging until you rev up the engine. This is a resistance wire (10 ohms) and is needed to protect the diode trio in the alternator, so you need to get it working.

This is the wire at the fuse panel powering all the fuses for the things that aren't working.

If that's the case possibly the ignition switch is bad?

LockDoc
__________________
Leon

Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles
LockDoc is offline   Reply With Quote
Old 01-14-2018, 02:11 AM   #10
VetteVet
Msgt USAF Ret
 
VetteVet's Avatar
 
Join Date: Jan 2005
Location: Kalamazoo, Michigan
Posts: 7,880
Re: Wiring problems before inspection

That's certainly a possibility and you'll have to tell him how to get it out Doc.
__________________
VetteVet

metallic green 67 stepside
74 corvette convertible
1965 Harley sportster
1995 Harley wide glide

Growing old is hell, but it beats the alternative.
VetteVet is offline   Reply With Quote
Old 01-14-2018, 11:39 AM   #11
LockDoc
The Original Thread Killer

 
LockDoc's Avatar
 
Join Date: Aug 2006
Location: Montezuma, Iowa
Posts: 17,390
Re: Wiring problems before inspection

Quote:
Originally Posted by VetteVet View Post
That's certainly a possibility and you'll have to tell him how to get it out Doc.
That's easy enough to do....

67's and some 68's don't have an accessory position, all others do. Just put the key in the ignition and "gently" turn it as far to the left as it will go. Insert a straightened paper clip in the hole (the large ones work best) and push the release pin down (go easy here, it doesn't take much pressure at all) and turn the cylinder to the left a little more. As you turn the cylinder you have to remove the paper clip or it will bind in the hole. The cylinder should pull out. You should not have to force anything.

LockDoc
__________________
Leon

Locksmith, Specializing In Antique Trucks, Automobiles, & Motorcycles
LockDoc is offline   Reply With Quote
Old 01-14-2018, 07:06 PM   #12
Robznob11
Senior Member
 
Robznob11's Avatar
 
Join Date: Feb 2004
Location: brownfield texas (west texas)
Posts: 1,582
Wink Re: Wiring problems before inspection

My first thought was ignition switch or brown wire as well. If not that, some fuseboxes have overheated and melted on the back side where all the terminals come together. Since you say its full of splices......I would replace the whole thing. Now if you want a factory fit . American auto wire is good. I chose to go the cheaper route (not quite as easy but very manageable for someone with a little common sense) I used a universal EZ wire 20 circ kit. I have no regrets. Its good quality, but not so plug and play....you have to make your own connections. Now with that said all will require this to an extent.....mine was only like $150 or less for the whole getup.
__________________
67 short fleet, bagged! W/ 3in body drop , 6.0/4l80e lsx, 3800 billet LU stall, 42# inj, sinister cam 230/236 .591/.601 110*lsa,brian tooley pushrods,prc 1518 springs, full tune, racetronix FP w/ HW kit , 1 3/4 stainless full length headers, 3" exhaust w/x and dynomax bullets, 12 bolt,moser axles,strange mini spool, richmond 4.10 gears,w/ 345x55x15 drag radials on the back!
........................ ___
.........________//__{\_____
,,,,,,,/__(⊙)___//___/__(O)_/
Robznob11 is offline   Reply With Quote
Reply

Bookmarks

Tags
dangling wires, electric, wiring

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 07:09 PM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Copyright 1997-2013 67-72chevytrucks.com