Cab/running lights and Dash lights went out...?

[4x4TruckinGirl]

Haven't had a chance to post up here recently......but, My cab lights/running and dash lights went out, both at the same time. I checked the fuses in the truck, the seemed to be okay. Any suggestions on where to go from here? Also, this may be unrelated or not, but my speedo and odometer went out about a month before the cab/dash lights did. My tach is a little wacky too.

mostly id like to get my running lights back working so i dont get pulled over for no tail lights and stuff........

 

[6 Nebraska IDIs]

Funny you live in FL because we had our truck do just that on a trip to FL.

Dont mean to scare ya or nothing, but be very careful of that truck until you rule out what I think is wrong with it.
With our truck everything went to crap within minutes of eachother and all we had left by the time it was done was headlights.
But with our truck the light switch had actually shorted out and then to top it off we had a nice little fire starting under the dash at the plug. We had to get a new light switch plus a new pigtail, and I luckily had enough wire on the pigtail to take care of the melted/fried stuff.

I suggest not driving it at night, or atleast without the lights on, until you can evaluate the situation.
You'll have to pull the dash bezel and dig out the light switch.
Oh, and this WAS on a 94 truck, so its not like Im talking about the older rat nest wiring of the old trucks. This was supposed to be safe Ford wiring, yea right.

 

[Diezel_Cowboy]

I'd bet that your light problem is in the light switch/wiring plug at the dash. Mine did the same thing as well as others here on the board. The wire/plug for the cab/marker lights gets hot and burns up and should be replaced. Save yourself some trouble and buy the switch and plug/pigtail from your ford dealer since the aftermarket switches are not as good.
Also read this tech article:http://www.oilburners.net/articles/runninglight mod.htm
The article explains the typical switch problem, however, when i replaced mine i did not add the relays just replaced the switch and pigtail and things have been fine since then. Not that the relays are a bad idea just that they are not necessary to fix the problem and be on your way again.

Your tach problem is a common thing. Mine does the same thing. The problem lies in the sending unit for the tach which is located on the cover where the oil fill cap is. It has two wires coming from it. You could buy a new one. I got one from a junk yard and it worked for a while then did the same thing as the old one. I have yet to purchase a new one so i dont know how long a new one will last either.

The speedo and odometer may be a fuse.

 

[zpd307]

yep, i just replaced my headlight switch and the harness. the harness was melted, luckily it did not start a fire. i also had to replace my tach sender. 66 bucks from the dealer.

 

[gandalf]

So, to recap:

1) Replace the light switch and any wiring that seems necessary.

2) Tach--replace the sender near the oilfill on the engine. It's a big nut, ~1 inch, with two wires.

3) Speedo-- probably the sender, located on the rear pumpkin, the front upper surface of the differential. On mine a single bolt holds it in place.

If you had an E4OD either a bad tach or a bad speedo would cause it to go into limp-home mode. Been there, done that.

 

[MIDNIGHT RIDER]

There is a tiny tan wire that goes from fuse-block to light-switch that is notorious for melting itself into the other wires and causing all sorts of problems.


Ford wiring is good for truck burning, and many have burned to the ground because of it.


Just replacing the switch/plug does not fix the problem; it only makes the lights work again; the problem is still there.


It is best to entirely eliminate the factory lighting circuit; just cut it out entirely and re-wire from one end to the other, using good BIG high-amp toggle-switches to control all of the functions.



I bet your trailer-lights are also controlled by the head-light switch; if so, that is a big NO-NO; trailer-lights should ALWAYS be on an entirely independent circuit, in no way controlled by the head-light switch.


If completely re-wiring is not done, at least do the relay modification on the head-lights and replace all the wires in the switch pigtail with heavier wires, especially that tan one.

I bet you find that tan wire has most of it's insulation melted away.

 

[LCAM-01XA]

Oh, you can control the trailer lights with the dash switch alright, just need to add a nice relay somewhere in the circuit - factory tow package trucks have that, well, from the factory, on anything else it needs added by the hitch installer.

 

[RLDSL]

Oh, you can control the trailer lights with the dash switch alright, just need to add a nice relay somewhere in the circuit - factory tow package trucks have that, well, from the factory, on anything else it needs added by the hitch installer.

That factory tow package lighting setup is great, just so long as some PO or mechanic or hitch installer along the line hasn't bypassed it.
My truck has a Western Hauler bed on it and the morons who did the bed install, instead of wiring the trailer wiring outlet plugs and extra bed lights into the tow circuit that's designed for it, the bozos chopped up the harness and wired the bed and trailer to the regular lighting circuit and they wired the tail lights on the bed to the tow circuit, and to top it off, instead of using that nice plug under the dash that ford put there for plugging a trailer brake controller into, they had done a butcher installation of the brake controller and run their own wires for that (poorly ).
I had to go into it and tear the whole mess out and put it back to factory

 

[4x4TruckinGirl]

Well dang..... Thats a lot of wiring for me to mess up!!!!!! I'm gunna have to tear into this on the weekend i guess..... errrr....... Im sure ill have more questions coming up..... but thanks ya'll...

 

[MIDNIGHT RIDER]

Even with relays, I dislike trailer circuits being controlled by truck wiring/switches.

I like my trailer-lights to be independently fused and independently switchable.


In her situation, which is an all to common situation due to shoddy factory wiring, if the trailer is wired to even a relay, yet controlled by the headlight-switch, she loses ALL lights, truck and trailer, leaving her in the dark to get run over.


When the trailer-lights are COMPLETELY independent, either can be lost without affecting the other.


I have my factory-lights still controlled by the factory-switch, yet on relays; then, the fifty-plus truck-markers are on an entirely seperate circuit, switched and fused by themselves; and, the probably a hundred trailer-lights are still yet on another circuit.


I can lose any one of the three and still have the other two, plenty well lit up enough for even the drunkest drunk to see me in the dark.

 

[RLDSL]

It's times like this that I really miss my old '63 Willys pickup. The entire underdash wiring on that thing consisted of 6 wires with inline fuses .
Talk about easy troubleshooting

 

[Diezel_Cowboy]

....................the fifty-plus truck-markers are on an entirely seperate circuit, switched and fused by themselves; and, the probably a hundred trailer-lights are still yet on another circuit.


I can lose any one of the three and still have the other two, plenty well lit up enough for even the drunkest drunk to see me in the dark.

I seriously doubt she intends on pulling a trailer with 50+ marker lights
The factory stuff (after i replaced the switch and pigtail) has worked fine for me...........BUT I'm not pulling a christmas tree

"50+ marker lights" on the truck and "100 trailer lights" PICTURES!?

 

[LCAM-01XA]

RLDSL, I had to deal with something like that as well, only not too bad - my truck had the heavy-duty 7-pin (not blade contacts) connector in the bumper, but they did a very poor job connecting the plug harness to the truck harness and things corroded real bad, besides trailers I ususally tow don't have the 7-pin connector anyways, so I replaced it with a 7-blade connector and I was very pleasantly surprised to find that almost all wires in the truck harness color-match to the trailer plug, made life a whole lot easier.

Also, they had a 4-way connector running off a break-out harness from the truck's own rear lighting, I pulled that one off as my 7-way came with a 4-way adapter - less wiring means less things to corrode or catch on fire.

As far as the controller is concerned, my factory plug was missing as well, but the wiring was all still there so I just spliced the universal harness of my P3 into it and all was peaches.

 

[LCAM-01XA]

"50+ marker lights" on the truck and "100 trailer lights" PICTURES!?

Plus one on that, night pics too

 

[MIDNIGHT RIDER]

"50+ marker lights" on the truck and "100 trailer lights" PICTURES!?

Plus one on that, night pics too

Alas, I am smart enough to get things lit up, but too dumb to figure out how to make a picture get from the wife's camera to here.


For now, just close your eyes and imagine it.