Fuse block replacement tutorial
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
Ok... I checked all three wires and here are my results.
#1 light blue/red - Hot with light switch turned all the way to the left, nothing when turned all the way to the right.
#2 light blue/red - Hot with light switch turned all the way to the left, nothing when turned all the way to the right.
#3 light blue/red - Hot no matter what position the light switch is in.
When #1 or #2 are hooked to the new fuse block with the ignition on - no dash lights (no matter what way you turn the light switch).
When #3 is hooked to the fuse block and ignition is on - + Dash lights (no matter what way you turn the light switch).
So does this mean that wire #1 and #2 must be for the dimmer?
Is #3 the wire that should be hooked to the fuse block and why does it have constant current?
#1 light blue/red - Hot with light switch turned all the way to the left, nothing when turned all the way to the right.
#2 light blue/red - Hot with light switch turned all the way to the left, nothing when turned all the way to the right.
#3 light blue/red - Hot no matter what position the light switch is in.
When #1 or #2 are hooked to the new fuse block with the ignition on - no dash lights (no matter what way you turn the light switch).
When #3 is hooked to the fuse block and ignition is on - + Dash lights (no matter what way you turn the light switch).
So does this mean that wire #1 and #2 must be for the dimmer?
Is #3 the wire that should be hooked to the fuse block and why does it have constant current?
Number 3 should not have constant current. It should work like #1 and #2.
The light switch supplys power and dims the Lt/Blue/Red wire circut.
How are you hooking this up to the fuse panel? The Fuse space that you hook up to the panel must be isolated from all other power sources except the one coming from the headlamp switches LtBlue/Red strip wire. Power comes from the headlamp switch to the fuse panel, originally, not visa/versa.
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Junior User
Joined: May 2009
Posts: 62
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I see what you are saying.
1. I should not have power from the fuse panel running through any of these wires.
2. They should run passively through a fuse in the box.
Now I need to figure out why one lt blue/red wire is hot all the time.
1. I should not have power from the fuse panel running through any of these wires.
2. They should run passively through a fuse in the box.
Now I need to figure out why one lt blue/red wire is hot all the time.
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Junior User
Joined: May 2009
Posts: 62
Likes: 1
If anyone has any suggestions on why wire #3 always has a current. I have a 6/12 volt meter, and it displays approximately 6 volts constant current, then when the light switch is on, it shows 12v of current.
I have no idea?
I have no idea?
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
It's a short in the circut somewhere. It may come down to unwrapping the harness and tracing the wire to see where it is. But lets try and narrow it down...
What I would do. is unplug the light switch and see if there is still power at the Lt. Blue/Red wire in question. If there is not power with it unplugged, then the headlamp switch is faulty and must be replaced. It's bleeding power through the switch when it's off, etc...
If there is still power with the switch unplugged, remove one fuse in the panel, one at a time, with the light switch still unplugged, untill the lt. blue/red stripe wire is dead. The fuse that you pull that makes the wire dead, is protecting the circut that the, Lt. Blue/Red stripe wire is shorted between. If none of them make the wire dead. The short is in a circut not protected by the fuse panel. Possibly the wire that feeds the fuse panel, or one protected by a fuse link.
Hope this helps
What I would do. is unplug the light switch and see if there is still power at the Lt. Blue/Red wire in question. If there is not power with it unplugged, then the headlamp switch is faulty and must be replaced. It's bleeding power through the switch when it's off, etc...
If there is still power with the switch unplugged, remove one fuse in the panel, one at a time, with the light switch still unplugged, untill the lt. blue/red stripe wire is dead. The fuse that you pull that makes the wire dead, is protecting the circut that the, Lt. Blue/Red stripe wire is shorted between. If none of them make the wire dead. The short is in a circut not protected by the fuse panel. Possibly the wire that feeds the fuse panel, or one protected by a fuse link.
Hope this helps
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Junior User
Joined: May 2009
Posts: 62
Likes: 1
Thanks for your help 81! Using your fuse panel technique I was pointed in the right direction.
Believe it or not there were approximately 10 wires that were bare wires touching and grounding to the frame under the truck near the transverse case where the previous owner had spliced into the rear lights. After repairing the wires, the dome light and dash wiring is working perfectly. Actually all the wiring in the truck is now functioning properly.
I did run into two unknown wires on my 2 hour journey under the 6 inch lifted ford (glad I went with the 6 inch now).
Purple wire hanging down near transmission????
Green wire hanging down near transverse case????
Cant seem to pinpoint these in the haynes manual. Any one know what they do?
Believe it or not there were approximately 10 wires that were bare wires touching and grounding to the frame under the truck near the transverse case where the previous owner had spliced into the rear lights. After repairing the wires, the dome light and dash wiring is working perfectly. Actually all the wiring in the truck is now functioning properly.
I did run into two unknown wires on my 2 hour journey under the 6 inch lifted ford (glad I went with the 6 inch now).
Purple wire hanging down near transmission????
Green wire hanging down near transverse case????
Cant seem to pinpoint these in the haynes manual. Any one know what they do?
Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
Believe it or not there were approximately 10 wires that were bare wires touching and grounding to the frame under the truck near the transverse case where the previous owner had spliced into the rear lights. After repairing the wires, the dome light and dash wiring is working perfectly. Actually all the wiring in the truck is now functioning properly.
I did run into two unknown wires on my 2 hour journey under the 6 inch lifted ford (glad I went with the 6 inch now).
Purple wire hanging down near transmission????
Green wire hanging down near transverse case????
Cant seem to pinpoint these in the haynes manual. Any one know what they do?
I did run into two unknown wires on my 2 hour journey under the 6 inch lifted ford (glad I went with the 6 inch now).
Purple wire hanging down near transmission????
Green wire hanging down near transverse case????
Cant seem to pinpoint these in the haynes manual. Any one know what they do?
For instance - Purple/White stripe wire is the Dual brake warning switch wire. The switch is located on the frame rail on the porportioning valve.
Solid Green is for the Right rear turn signal and brake lights.
There are a half a dozen green and purple wires, all with different color stripes or markings. Why it's important to find out if there is a tracer color or stripe on the wires.
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Junior User
Joined: May 2009
Posts: 62
Likes: 1
Honestly they looked solid in color, but I will take a towel out and wipe them off to be sure.
There are two green wires. One small light green wire which is hooked to my turn signal just as you indicated.
This is a larger solid darker green wire.
Again, I am not 100% that they are solid, I will check them out tomorrow.
There are two green wires. One small light green wire which is hooked to my turn signal just as you indicated.
This is a larger solid darker green wire.
Again, I am not 100% that they are solid, I will check them out tomorrow.
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Junior User
Joined: May 2009
Posts: 62
Likes: 1
So you are correct. The purple wire does have a white stripe.
The solid green wire appears to run to the mid gas tank sending unit. This may be a spliced wire. The gas gauge pegs full when this is grounded.
Where should this purple/white wire run to and from?
The solid green wire appears to run to the mid gas tank sending unit. This may be a spliced wire. The gas gauge pegs full when this is grounded.
Where should this purple/white wire run to and from?
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Post Fiend
Joined: Jul 2004
Posts: 8,786
Likes: 28
From: Northern California
Purple/White wire: There should be a switch on the porportioning valve. It should plug into this switch. The other end goes to the Brake Warning Lamp in the instrument panel, and wyes off to the ignition switch. It goes to the ignition switch as well because it lights the lamp during start, to check the bulb.
There is also a green wire, (no tracer) that goes to the Mid tank sending unit. Confirmed.
There is also a green wire, (no tracer) that goes to the Mid tank sending unit. Confirmed.
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