Instrument Lights and Daytime Running Lights Not Working

[Double-A]

I'll have to do the tests tomorrow.
The parking lights I'm not sure if that includes the taillights I didn't think to check. But it includes the front orange lights in the grille and the side marker lights.

The clearance lights are 5 orange lights on the roof.

[Double-A]

OK. The parking and clearance lights include the orange lights on the roof, orange side lights, orange lights in the grille, and the taillights.

The headlight switch is still wired as pictured.

The orange pair are hot with the jumper installed.

The 12GA red wire behind the dash for the headlight switch is hot with the jumper installed. The dash lights still don't work at all (they did before I got it apparently).

[bd]

I jumped the output on the alternator with the red wire ... the parking lights and clearance lights turned on with the [headlamp] switch off and ignition off....

Is this still true?

With the jumper installed, if you unplug the brown wire from the headlamp switch, do the running lights (park, tail, side marker & roof lights) continue to illuminate?

With the jumper installed and the headlamp switch turned on and rotated CCW, do you measure 12 volts on either side of the 5-amp "INST LPS" fuse?

[Double-A]

That quote is still true. The lights turn off when the brown wire is disconnected.
I will have to check the fuse terminals you speak of.

[Double-A]

OK. With the headlamp switch off and ignition off, and the jumper installed there was voltage at the 5 amp "INSTR LPS" fuse. With the switch on and rotated counterclockwise it still had voltage, the actual instrument cluster lights still don't come on. However I noticed that the Heater/AC selector switch light was on (I believe it would have come on when the switch was rotated counter clockwise without the switch itself being on)

[bd]

With the jumper connected, does the INST LPS fuse lose power if you unplug the green wire from the headlamp switch?

[Double-A]

Yes it does.

[bd]

Following is a summary of the corrections I recommend.  I'll be happy to answer questions and assist you as you wish.  Perform all repairs with the ground cables disconnected from the batteries:

• Reroute the primary starter wiring away from the exhaust.
  
  
• Remove the wires from the firewall junction block and scrub the posts clean with a small stainless steel wire brush, removing all corrosion and residue.
  
  
• Cut off the yellow terminal installed by the PO at the junction block then strip 1/4" of the wire and burnish the copper strands until they are shiny.  Securely crimp, solder and heat shrink a new terminal in its place.  Remove and discard the blue wire at the junction block that doesn't connect to anything.  Reassemble the wires to the junction block after liberally coating the studs and terminals with antioxidant paste available from your local hardware store.  (Henceforth, every time I recommend replacing a terminal end or installing a new fusible link, all terminals and splices should be tightly crimped onto shiny copper wire using uninsulated, seamless, tinned copper terminals, soldered with 60/40 rosin core solder, and shrink sealed using adhesive lined heat shrink that protrudes 3/8 - 1/2" beyond the end(s) of the terminal and overlaps the wire insulation to provide a watertight seal).
  
  
• Post another image of the firewall junction block that shows more of the attached wires, so I can determine whether you need to install a 6" long 16-gauge fusible link between the junction block and the 12-gauge red wire running to the firewall bulkhead connector.
  
  
• Replace the headlamp switch and connector (the switch is shorted).  Remove and discard the "blue" wire that presently feeds power to the headlamp switch and substitute the factory 12-gauge "red" wire that the PO abandoned under the dash.  Also, insert the "white" dome lamp wire into the appropriate cavity of the headlamp switch connector.
  
  
• Cut the 16-gauge "red" wire coming out of the regulator plug at the alternator where it splices to the 12-gauge "red" wire that runs to the bulkhead connector.  Discard the yellow splice.  Make up a 16-gauge fusible link with a 1/4" ring terminal at one end (refer to How to make a Fusible Link in our Technical Pages).  Crimp the opposite end of the fusible link together with the "red" lead coming from the regulator plug such that both wires share the same end of the bare 12-gauge splice.  Slip heat shrink over the wire pair well past the splice and securely crimp the opposite end of the splice onto the 12-gauge red wire running to the bulkhead connector.  Solder the splice then heat shrink it.
  
  
• Clean the wiring harness connections to the back of the instrument cluster and/or repair the open in the cluster ground to the cab sheetmetal near the park brake pedal.  Check the instrument cluster bulbs and replace as needed.
  
  
• Check all of the vehicle grounds, making sure they are present, clean and tight (i.e., batteries-to-engine, battery-to-frame, battery-to-radiator support, engine-to-firewall, bed sheetmetal-to-frame, and instrument cluster-to-cab sheetmetal under the dash.
  

I think the foregoing list should address most of the issues you mentioned, although other issues may materialize as you progress.  Once the above is completed, you should evaluate the glow plug wiring as well.  It appears that the PO removed the factory fusible links protecting the glow plug circuit - a perfect setup for burning the vehicle to the ground.

[Double-A]

I'm sure many questions will come up. I was unaware that the glow plug wiring has been so altered... they function like they should, but I should add that a PO added a push button to turn them on manually...

I am also not sure if there even is a instrument cluster ground, I believe the PO also replaced the instrument cluster and the instrument panel since they don't quite fit right.

I am not sure of what yellow splice you are talking about in number 6 too.

There is a possibility this truck will be sold though, it some other issues that I am not sure if its worth keeping over.

[bd]

I am not sure of what yellow splice you are talking about in number 6

Look at the attached image.

[Double-A]

Ahh ok. How am I going to get power to the headlight switch though? That red wire is the one I was jumping....

Maybe I need clarification on #6. Just want to be sure I am doing it right so I'm not like the PO.

[bd]

You will sever the red wires on the right, circled in yellow (previous image), and then rejoin them together with the new fusible link from the output post of the alternator. 

The three wires need to be connected at the new splice.  The splice joining the white and brown wires circled in blue should be replaced with an 18-GA splice (or 16-GA splice if the 18-GA is a little too small). 

Before assembly, the wire strands need to be shiny clean for solder to flow and properly adhere.  Don't forget to slip the heat shrink tubing over the wires before you crimp them together.  And then slip the tubing up the wire well away from the splice before soldering so it doesn't shrink prematurely.

[Double-A]

So just redo the splice on the brown wire (with a new fusible link), and the same for the red, but make another fusible link to go from the red regulator wire to the output post? Maybe I need a picture, I understand what I need to do but I guess I need to visualize it..

[bd]

Commonly used automotive wire gauges are 18, 16, 14, 12, 10, 8, 6, and 4.  With respect to wire gauge, the greater the number the smaller the wire size.  Hence, 18-gauge wire is much smaller than 10-gauge wire; 4-gauge and larger wire is typically used for battery cables.

"Yellow" butt splices are for joining 12- to 10-gauge wires.
"Blue" butt splices are for joining 16- to 14-gauge wires.
"Red" butt splices are for joining 20- to 18-gauge wires.

The PO used 12/10-GA splices on everything regardless of actual wire size.  Replace the splice connecting the white and brown wires (blue circle) with the appropriate size (probably 18-GA).  That is, just cut the old splice out and then resplice the white to the brown.  You're simply downsizing the physical size of the splice to correctly match the wire sizes.  I directed you to do this, because mismatching terminal size to wire size can result in poor conductivity, especially as the connection ages.  The yellow butt splice is way too big for the white/brown pair.

The "red" regulator wire is the voltage sensing lead for the regulator.  It needs to be connected to battery (B+) so the regulator can do its job and control alternator output.  For now, the only new fusible link at the alternator is going to connect the two existing red wires to the output post (B+).  So, the two existing red wires will still be electrically connected; but now you will add a new fusible link that connects them to the alternator output post too.  In the process of connecting the three wires together, you will replace the existing splice (yellow circle).

Does this make more sense?

[Double-A]

Could you possibly show in the picture too? The instructions help a lot but I feel if I were to see what you mean I would understand much better. I dont really understand what Im doing with the red wire... I think I understand the white wire cause I am just supposed to redo the splice right?