need help please, I think my schematic is wrong?
Thread Starter
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Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
need help please, I think my schematic is wrong?
So when I pull the headlight switch out one click to turn on the running lights, it blows the fuse 4 (taillights, front markers, and instrument cluster). Pulled all the way out doesn't hurt anything; the headlights work just fine. I looked at the wiring coming out of the back of the headlight switch and can't get it to match to the Chilton's schematic:
Back of headlight switch:
black/orange
orange/black
yellow/black
green/yellow
brown
light brown/white
white/blue
black/pink
red/yellow
Schematic shows:
I need to know what the wires coming out of that switch go to so I can isolate the markers/taillights/instrument lights one at a time and figure out what's shorting out. Any ideas would be greatly appreciated. I need to sell this thing because I'm moving from Washington state to North Carolina or Texas in the next couple of weeks but no one wants to buy it because of this problem.
Please please pleeeeeeaaaaaaase help!!
Back of headlight switch:
black/orange
orange/black
yellow/black
green/yellow
brown
light brown/white
white/blue
black/pink
red/yellow
Schematic shows:
I need to know what the wires coming out of that switch go to so I can isolate the markers/taillights/instrument lights one at a time and figure out what's shorting out. Any ideas would be greatly appreciated. I need to sell this thing because I'm moving from Washington state to North Carolina or Texas in the next couple of weeks but no one wants to buy it because of this problem.
Please please pleeeeeeaaaaaaase help!!
Lead Driver
Joined: Sep 2002
Posts: 9,182
Likes: 12
From: Gateway to the West
The "main light switch" is the headlamp switch. The other one in the diagram is the multi-function switch... the turn signal, high beam, etc. stalk on the steering column. As for the issue with the first detente (stop/parking lights) causing a dead short, I have one question before I make any real suggestions as to how to proceed. If you pull through the first detente to the second (headlamps) rapidly, does the fuse/circuit breaker hold or does it trip anyway? I know your initial post said everything was fine. I guess I am wondering if the parking lights actually come ON with the switch in the second detente (headlamp) position do they function normally and come on WITH the headlamps?
Thread Starter
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Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
Sorry I worded that funny. The parking lights blow the fuse regardless of how fast I switch the headlights on. I was just saying that the headlights work fine, it's isolated to only the parking lights and the instrument cluster.
Moderator
Joined: Jan 2001
Posts: 57,025
Likes: 2,756
From: Virginia
People don't realize the headlight switch is one ****, but it has different sections to it, and they are fed by different fuses and power supplies. Simply put, your headlight circuit is fine, and the running lights circuit has a short. The headlights are fed by a different power source, so that's why they still work.
The running lights come out of the headlight switch on the brown wire. This brown wire goes all over the truck, front to rear, feeding the front running lights and the rear taillights and license plate lights. Because of this, it's going to be hard to track down the problem. The best way is to first look at problem areas. These areas are anyplace someone other than the factory has done some wiring. If you have a trailer plug added, look there first. If you have added running boards with lights, look there. People do not use good wiring practices, and that's usually the problem.
The only other thing you can do is find some major plugs and disconnect different parts of the truck to try and isolate the problem.
The running lights come out of the headlight switch on the brown wire. This brown wire goes all over the truck, front to rear, feeding the front running lights and the rear taillights and license plate lights. Because of this, it's going to be hard to track down the problem. The best way is to first look at problem areas. These areas are anyplace someone other than the factory has done some wiring. If you have a trailer plug added, look there first. If you have added running boards with lights, look there. People do not use good wiring practices, and that's usually the problem.
The only other thing you can do is find some major plugs and disconnect different parts of the truck to try and isolate the problem.
Thread Starter
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Fleet Mechanic
Joined: Jan 2009
Posts: 1,964
Likes: 2
From: Fort Worth
People don't realize the headlight switch is one ****, but it has different sections to it, and they are fed by different fuses and power supplies. Simply put, your headlight circuit is fine, and the running lights circuit has a short. The headlights are fed by a different power source, so that's why they still work.
The running lights come out of the headlight switch on the brown wire. This brown wire goes all over the truck, front to rear, feeding the front running lights and the rear taillights and license plate lights. Because of this, it's going to be hard to track down the problem. The best way is to first look at problem areas. These areas are anyplace someone other than the factory has done some wiring. If you have a trailer plug added, look there first. If you have added running boards with lights, look there. People do not use good wiring practices, and that's usually the problem.
The only other thing you can do is find some major plugs and disconnect different parts of the truck to try and isolate the problem.
The running lights come out of the headlight switch on the brown wire. This brown wire goes all over the truck, front to rear, feeding the front running lights and the rear taillights and license plate lights. Because of this, it's going to be hard to track down the problem. The best way is to first look at problem areas. These areas are anyplace someone other than the factory has done some wiring. If you have a trailer plug added, look there first. If you have added running boards with lights, look there. People do not use good wiring practices, and that's usually the problem.
The only other thing you can do is find some major plugs and disconnect different parts of the truck to try and isolate the problem.
I found the brown wire with the white tracer that goes from the fuse to the headlight switch and then the brown wire that comes out. Where does the brown wire branch out at?
Moderator
Joined: Jan 2001
Posts: 57,025
Likes: 2,756
From: Virginia
Comes out of the headlamp switch and goes to the main harness under the dash. There is a splice near the wanring chime take off in the harness, and this is were it splits to go to the roof lights, keyless entry, warning chime, trailer wiring, and the rear lights. It continues to a plug in the firewall. Goes through the firewall, and out near the take off for the front parklamp on the driver's side. Near there is a splice were it goes to the left and right front lights.
I would not recommend you start unwrapping the harness. I would look at possible problem areas first. And it looks like you could unplug the connector at the firewall, and split the harness front and rear.
I would not recommend you start unwrapping the harness. I would look at possible problem areas first. And it looks like you could unplug the connector at the firewall, and split the harness front and rear.
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Fleet Mechanic
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