None of my lights are working. Need some help.

[WILD_PHIL]

I have an 86 CC 4X4 3500. 454 under the hood. Had a wiring nightmare under the hood. With lil knowledge of auto electronic wiring I tried to clean it up. Did a pretty good job but now none of my lights work. I did remove the black box located in the center of the fire wall. I don't believe any of these wires were actually hooked up. Anyhow if any other info is needed to help me track this down please let me know. I put this truck up for sell and got the trade of a life time.

Below is a picture of me and the truck.

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[WILD_PHIL]

I did check the fuses. Not to say one isn't missing but all the fuses in the box are good.

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[bake74]

     Couple of questions first.  You said you rewired, did they work before you rewired ?  Did they work after you rewired and the quit working ?
     Here is the 1986 manual in our tech section.
    Here is the wiring diagrams for our trucks also in the tech section.  Look under the appropriate year for your truck.
    The "black box" that you said you removed sounds like the junction block for the main power wire, did you just hook both those wires together that were running through the junction block ?

[WILD_PHIL]

Bake I chased the wires down and don't believe they were hooked up. I figured it was some kinda voltage regulator but it wasn't hooked up. This truck isn't my DD. It's been a toy for the 9 years I've owned it. They did work before the rewire. I have a few wires from the back of the fuse box that aren't hooked up.

Back to a Cummins? Looks like it.

[WILD_PHIL]

That blue wire that isn't hooked up has an identical colored wire running from the headlights.

Back to a Cummins? Looks like it.

[WILD_PHIL]

My thought is that one wire was disconnected. I think that because none of my exterior lights are working.

Back to a Cummins? Looks like it.

[bd]

WILD_PHIL, you're leaving out important information.  Over the Internet we can't see what you're looking at.  Provide more detail.  Post pics.  Black box where?  Is it under the dash?  Is it in the engine compartment?  What "blue wire?" 

Do the dash lights work?

Did you look at the 1986 Wiring Manual, beginning on page 10? 

Check the fusible links at the firewall junction block and at the starter.  If you had the firewall bulkhead connector apart on the driver's side, make sure it's properly plugged back together and that you didn't bend a terminal or dislodge a terminal out of its connector.  At this point I agree that you may have disconnected a circuit accidentally.  Following a methodic procedure will discover it.

[bd]

Looks like you posted while I was typing - lol.

Post a pic of where the "blue" wire is connected to the headlights.  Looking at the factory schematic that dark blue wire originally tied the electric choke to the dash "Choke" indicator lamp.

And, be sure to perform the checks previously mentioned.

[WILD_PHIL]

Bear with me as I answer some of these questions. The first (above) picture shows the cut blue wire. In the second (above) picture the wire is between my fingers. The rest of it is to the right of my hand in the second picture. The black box was on the firewall right above the motor in the engine compartment. If the bulk head is what I took pictures of (I'm electronically retarded) then I did not remove it. I think required was an incorrect statement, I just removed the wires that were not hooked up to anything. I zip tied wires together and tried to clean the engine compartment up some.

The picture shows the nightmare I was dealing with. The black box I mentioned is sitting on the AC housing.

Back to a Cummins? Looks like it.

[bd]

I believe that "black box" is the speed switch that actuates a vacuum solenoid valve, which controls the throttle kicker on the carburetor.  The vacuum solenoid typically bolts to the intake manifold near the carburetor.  Although the throttle kicker is there, it appears that the vacuum solenoid valve is missing.  The black box has no bearing on the lights.

There's a 1/4" electrical stud protruding from a black plastic base that attaches to the firewall about 12-15" above the left (driver's side) valve cover.  There's a 12-gauge red wire that connects to the stud through a 6" long fusible link.  Give a light tug on the wire to see if the link stretches or pulls apart.  There are two or more fusible links attached to the 3/8" battery cable stud on the starter, as well.  Check them the same way and post an update.  You never answered my earlier question:  Do the dash lights work?

[WILD_PHIL]

Been busy with easter and family. Took tomorrow off and plan on getting in to this. Thanks for the pointers so far.

Back to a Cummins? Looks like it.

[WILD_PHIL]

OK simple as a wire not hooked up. Anyone have any ideas as to why my truck will start when cold and not when hot. I put a different starter on it and got the same thing. It wasn't a new starter but I'm not sure if it is a starter.

Back to a Cummins? Looks like it.

[bd]

Not start as in won't crank?  Or cranks, but won't fire off?