carry a jumper in case it fails

 

so it happened again today. still not sure whats causing it. i was driving, shut the truck off. then when i went to start it, nothing. seemed like the same thing so i checked that fuse and it was fine. made sure it was really in the holder, then tried again and it started.

then im driving down the road and engine or trans stutters with a big jolt so i pull over and as im pulling over it stalls. turn the key, and nothing again.

check to make sure the fuse is good and turn the key and it starts.

i dont get it.

 

it sounds like a loose wire short, a least its not blowing the fuse, carry a test light with you, next time it fails, i bet its right at the source, check power at both sides of the fuse, when it quits, try not to move anything when you check it, ground the microclip for the test light at the battery, check fuse power, if good, try grounding light on motor, then do the wiggle check, also check power downstream at fuel solenoid, your close.

 

So just to get things one record. with truck starting and fuse still good:
with test light grounded, i get light on both sides of fuse with key off.
when on, i get the same results but touching the light to the fuse causes the heater to click on and off.
here is 2 short clips i took:

this one is just tracing the wires a short distance . one direction to the harness, the other branches into 4 paths with one going to what i think is a solenoid? related to the trailer plug?


2nd clip is what i noticed happens when i touch the fuse itself. that cat meowing at the end is not actually a cat but some fuse related sound.


so i imagine the fuse holder is bad? but it still seems like there must be another problem thats causing it to blow?

 

Also. I can now shut the truck off by squeezing that fuse. When this happened i took the fuse out and one of the legs had a black burn mark on it. So again I think I need a new fuse holder or just to tighten the teeth inside.
Still seems like I'm missing something though or why would he have put that fuse there.

 

The fuse is there to replace a fusible link. I would replace the fuse holder with a new one, then you know that the wire ends are crimped good and that the holder its self is not the problem. They only cost a few bucks, also get the heat shrink connectors so that its all sealed up and not corroded in a year or two.

Now if the fuse blows again you don't have to guess if its the holder or connections and can move down the line.

Just curious, have you always had a 20 amp fuse in there?

 

I crimped in the teeth on the fuse holder and couldn't get it to shut off the engine by wiggling it anymore. So I think that's good for now. Now just gotta wait and see if I blow a fuse again down the road.
I've had the truck for about a year now and it had that fuse in when I got it. And yeah always the 20 amp

 

that is the fuselink fuse holder replacement? definitly a loose connection, the first video reveals a constant duty solenoid, that will power your trailer plug if wire routes correspond, if the fuse does blow, temporarily disconnect that solenoid, to see if it reoccurs, ive seen alot of problem loose trailer plug internals, or chaffing of the insulation along the frame to short. the loose fuse wire repair should keep you running.

 

Alright thanx again. I guess now we wait till my fuse blows again. Then I'll try removing that solenoid form the circuit and see if it helps.
Is there anyway a fuse holder that doesnt grip the fuse tight can cause it to blow?

 

the connection loose wont carry load, it will heat up, similar to the fuse, it gets too hot past its capacity, fuse blows

 

alright so it happened again and now i get to do some more problem solving. unforutunatley it happened while i was 3 hours down a logging road. but i got home by hotwiring the fuel solenoid. i removed the 2 wires on the solenoid this time but then i didnt have blinkers guages wipers or blower.
so please correct me if im wrong on any of this:

-i get power on the batt. side of the fuse, so everything is good on that side and the problem must be on the other?

-hot wiring the solenoid with its original wires off leaves me with none of the above working. so all of those must be linked and get their power from the same source. so what powers the fuel solenoid???
-hot wiring the solenoid with its original wires on causes everything to work, even starting with the key. so i could be wrong but that tells me that that whole circuit is good and theres no shorts?? shouldnt something heat up or smoke or spark if there was a problem in that circuit?

SOOO...
I replaced the fuse holder, fuse still blows.
i tried taking out all the fuses from my fuse box, and fuse still blows.

could the problem just be my ignition swithch? can that cause an intermittant electrical problem? or can a bad relay cause these symptoms?

and then a question for wannadiesel or anyone else who has these trucks wiring memorized. this mystery fuse turns into a thick red wire just befor it goes through the fireweall. is this going to my ignition? then from there the power is distributed between everything else???

 

Here are some wiring diagrams from the sticky, download all of them to your computer hard drive then it is easier to view them using your image viewer.

Not sure which circuit you are looking for, what gauge wire is in question and where does it go?

This is why I wish people would not cut wires without at least leaving a drawing in the glove box telling what they did.

http://dens-site.net/Dodge_CTD/1991.5-Wiring_Diagrams/

Jim

 

It is nigh impossible to long-distance diagnose an electrical problem on a twenty-year-old truck that has had any electrical work done over the years.

We cannot see what others have done.

Some peoples work is better by far than factory, while others is a nightmare of suit-case connectors, twisted wire, and big wads of black tape.


My advise to anyone experiencing electrical problems on these trucks is to FIRST completely do away with that four-legged "duck-foot" splice at the fuse-links, leaving that wire to ONLY supply the alternator, and it would be best to upgrade it.

Splice new wire leads through appropriate fuses/breakers that bypass and eliminate all the fuse-links and go straight to a HOT source from battery-positive.


Then, look under the factory fuse-block and remove and externally fuse all wires that are all melted and burnt.

Determine the blower wire and power-window wire and re-route them to fused HOT elsewhere than the factory fuse-block; likewise for the wipers.

The key-switch and factory fuse-block will then no longer be burdened with these loads.


Once those operations are done, nearly all old-age problems with the factory wiring will be cured.


I never have any issues with any of my add-ons, such as trailer plugs, auxilliary lights, and such, BECAUSE I never splice any of this stuff into the already over-taxed factory system.


Trailer plug wiring should never in any way be connected to the trucks wiring.

The truck's headlight switch should NOT turn ON the trailer lights --- period.

Trailer signals should be operated via relays, such that the trucks signal wiring only must trigger the relays.


Etc. and etc.


Carry on.

 

So I hooked up a test light to the fuse holder. With the key on, it lights up showing the short.

I started unplugging things that are in the same circuit and when I unplugged the ignition switch plug, the light went out. So I think that confirms that the ignition switch wire is good and that the problem is the switch itself or something after it. But from what I can tell from the wiring diagram, the ignition just provides power to the fuse block.

So if I unplugg all the fuses and the light stays on does that mean the ignition switch itself is bad?

And would a bad ignition switch cause a fuse or fusable link to blow?

 

another update.
so with the ignition switch unplugged, i used a jumper wire to connect the 12guage red to its spot on the switch, then i connected each wire one at a time. the blue wire and the black with white stripe wire both caused the tester to light up, which i think tell me that my ignition switch is fine and theres a short somewhere on either of those wires.

So when conecting the bk/white wire, the wiper relay under the dash buzzes. so theres something weird with my wipers. unplugging the relay causes the light to go out.

in the schematic the blue wire leads to the fuse block, and unplugging those fuses doesnt turn off the light. so the problem lies somewhere else on that blue wire. I have the schematic but am having a hard time following / understanding where it goes to.

any other tips would be great.