I think we've got a dead short here somewhere.


No wonder the body lights weren't working!
I don't know how it didn't burn the truck down, either.
We have everything from the battery forward removed, and started on everything under the cab, short of the fuel sender. The ABS unit has been by-passed so those wires are coming out, too.
89 D350 c/c, with a flatbed on it.
Oh, that was a 30 amp fuse that melted. We popped a 15 while working on it, and I do mean popped. I heard it let go while checking for function on the wires we were cutting out.

 

Those don't look like genuine BUSS fuses; any other brand of fuse will melt just like pictured.

Actually, the old glass tube fuses are much safer in that they will "shoot" and not melt.

I have my many many marker lights separately fused by group/location with small amperage fuses; these individual fuses are supplied via a main feed of two separate higher amp fused wires switched by a DPST toggle.

If something happens in any group of lights, it "shoots" the fuse for that group and nothing else; thus, tracking down the problem is narrowed down to only that particular group of lights.

I have my live-stock trailer also wired thus, with a big fuse-box located under the neck; this fuse-box is actually a gutted house-hold circuit-breaker box that is weather-proof.

In the many years since these improvements, I have never had a fuse problem on truck or trailer.

I can remember the days when a wire would get pinched somewhere hidden within whatever trailer I was pulling and put the whole truck, trailer, and all in the dark, and me not have the slightest clue where to start looking.

It is hard to coerce me into pulling anyone else's trailer for that very reason.

I hope you find your problem.

My bet is someone either drilled or torched holes through the steel frame-work of the flat for running the wires and one has worn through the insulation.

 

Under my truck is a waterproof junction box with fuses and relays in it for all the trailer circuits except brakes. If a trailer circuit shorts out, it takes one fuse out of the truck, leaving all truck lights and the rest of the trailer operating.

And yes, it's always someone else's trailer that takes out a fuse.

On these old Dogs:
Headlamp circuit is under wired and tends to overheat. Front engine compartment relays and fuses are the solution.

1 ton marker and tail light circuit is wired with 18g. Totally inadequate, especially if you wire in a trailer on the same circuit. There's a splice in the harness near the headlight switch where the circuit splits to front, back, dash, and clearance. That's a good place to individually fuse the separate wires. At least, put a relay near the light switch and supply the tail/clearance lamp circuit with a separate fuse.

Heater motor circuit..... more of the same.

 

Beware of Chinese fuses, sometimes they don't open when they should.

 

Every factory Dodge truck fuse-block that I have ever seen has the blower-motor fuse melted into the block, caused by the blower trying to draw sufficient amperage through a wiring circuit that is drastically insufficient to the task.

I remove the blower circuit and power-window circuit from the fuse-block AND key-switch, routing them with much bigger wire to battery HOT --- NOT the post on the battery, but a remote stud I have added for such purposes.
Both the fuse-block and key-switch are better for the loss.

It is also good practice to route all key-switched circuits through one or more constant-duty solenoids and the key-switch's only task be to turn ON the solenoid(s).

Of course, the first endeavor is always to eliminate that truck-burning fuse-link mess.

 

The only company I know that sells a replacement.

 

The Lucas stuff...brings up the real reason Brits drink warm beer...Lucas also makes refridgerators.

 

Like this?


Here's my under carriage trailer relays.

 

I once read somewhere hat the reason Brits don't build computers is they cant get them to leak oil.

 

J Martin, you and Bearkiller must be OCD, but in a very good kind of way. Wish I had your all's patience, abilities and perserverance. And of course Jim Lane's.

I'd like to see the truck that the three of you could build...

 

Well, now I'm stumped.
This is the 89 dually cab and chassis the boss' boy bought last month. The headlights and brake lights were the only ones working.

We stuck a 15 amp fuse in the fusebox and the marker lights all came on, including the cab lights.

Last night we had all the front wiring pulled and the signal wires (I am only adding a couple small LEDs to it for now) marked.

This morning we got the fuel sender unplugged, and pulled the entire rear harness out, and separated the fuel sender wires from the rest. They were put in convoluted tubing and put back in place. The fuel gauge worked.

Got the tail and brake lights figured out at the 8-way plug behind the intake heater solenoids and marked both brake light wires. Got the brake lights wired back in, and we only have a left brake light, and left turn signals.

Used the feeds for the left headlight for power to trigger the high and low beam relays. Now there is no power to either of those wires.

Same story on the wire for the front marker lights. Hooked it up to trigger the marker light relay. Now there is also no power to it.

Once again, all fuses are good in the fuse panel.

The farthest back the original harness now goes is the fuel sender. The ABS unit was by-passed in the rear some time ago, so we eliminated that wiring. I am only using 2 wires out of the 8-way connector by the heater solenoids. The cab lights, interior lights, and a 2 relays will be the most load the light switch sees now.

But I'm stumped on where I lost the power between the switch and the installed relays. My next step was going to be checking the bulkhead connector. I still have cab lights, gauge lights,and a high beam indicator inside.

One more thought, the signal switch is going bad. Would it be possible if it decided to finally completely give out, that it wouldn't allow headlight and one signal power back out of the cab?

 

[QUOTE=j_martin;3249853]Like this?


[QUOTE] where did you get that ? I like it

 

http://www.delcity.net/store/8-Point...Block/p_801580

 

Thank you sir.

 

Yeah; very similar, except due to financial constraints mine are home-made.

Years ago, I discovered that wires and terminals lived a lot longer when they were not connected to a battery full of acid and the resultant chemical reactions.

Instead of having dozens of corroded wires and ring-terminals, the only thing rotting on the battery post is the short cable that feeds the remote stud, and it will last a long time if things are kept tight and slathered with Vaseline = the best thing to ever happen to copper wires.