Why I asked, and you would be correct, this suggests RH Front of the truck, or main harness.

Not likely but it's theoreticly possible. The Cab to engine ground, and the main harness to dash ground. Check and make sure those are good.

The next test will require your multimeter set to Ohms. We are going to check the continuity of the wires now.

Disconnect the battery.

With the headlamp switch unplugged, the cluster unplugged and the front RH, and rear harness disconnected, I want you to test continuity with the Brown wire on the headlamp connector, with the brown wire on the front main harness connector. (you will probably need longer leads) The multimeter should read continuity.

Then I want you to test continuity between the Brown wire and the White/Blue wire at the Front connector, there should be no continuity present.

If there is, continuity, the problem is in the main harness somewhere, because everything else is disconnected.

If no continuity. Do the same continuity test, between the White/Blue and brown wires at the front connector, except plug in the rear harness. If this causes continuity between the White/Blue and brown wire, the problem is in the rear harness.

If no continuity. Do the same continuity test, between the White/Blue and brown wires at the front connector, except now plug in the cluster. If this causes continuity between the White/Blue and brown wire, the problem is in the cluster.

Keep doing this until you get continuity between the white/blue and brown wire, or everything but the RH front harness is pluged back in. If no continuity shows up with everything but the front RH harness connected, the problem is in the right front harness.

This testing, although extensive, should isolate the problem to one specific section.

 

Double post.

 

yea i was wondering about that...well i got rained out today, but first thing tomorrow after work ill try those tests and let you know what i find

 

ok..sorry it took so long, been so damn busy..anyway

i did all of your tests and i did not get continuity in any of them besides the brown on headlight switch to the brown at front plug

even with the front harness plugged in and all the bulbs disconnected i still have the same problem, a constant power when the headlights are on and the RH turn signal is on

if i test continuity in the front RH harness from the brown wire to the green/brown wire i have continuity and from brown to red/black i have continuity...not sure why

also i pulled the light harness out and checked it out really close and found nothing wrong, i also had two others laying around and tested them too, no luck..

 

since it is only shorting out when i flip the lights on, could it have something to do with the light switch?

the new light switch i got had an extra prong on it then my old one, but my plug from the harness had a dummy slot for the prong so i thought nothing of it....could this be an issue?

 

Ok, so you are saying that the brown wire, and the White/Blue wire passed the continuity checks, and they are not crossed, correct? No Continuity between them at all, with everything disconnected, and even with everything plugged in, correct? And you already checked the lamp sockets on the right hand side, for proper ground, and they passed.

If this is the case, I want you to do some more continuity checks, but now at the headlamp switch. With the battery disconnected, I want you to see if you have continuity between the Lt. Blue/Red wire at the headlamp switch, connector and the White/blue wire at the instrument cluster.
We are going to check to see if there is a short between the Instrument cluster illumination lamp circut, and the RH turn signal circut.



This is the low and High beams circuts. You got continuity because they share the same power source in the headlamp switch, and they share the same ground.

 

Well, the problem is connected to one of the circuts that plugs into the light switch, but it's not the switch itself in this case.

Since you say all the tests you did, passed.

I'm now leaning toward the instrument cluster illumination lamps circut, and the RH Turn signals are crossed in some way.
The tests described in the last post should tell if this is the case or not.

 

ok test fail!

ok so i had the front harness disconnected yet and then i unhooked the battery,no continuity

then i redid the wire harness(rewrapped it cuz i had it apart yesturday to check it out) and i plugged it in and then i had continuity between the blue/red wire on the headlamp switch and the white/blue wire on the cluster plug....

 

Ok that's narrowed it down,

It's between the headlamp switch and the cluster plug.

You either have a bad ground at the cluster, or bad dash ground, or the blue/red wire is shorted to the White/Blue wire somewhere in the main harness behind the dash, or in the steering column going to the shift indicator lamp if an automatic.

Check all the ground first behind the dash. Make sure they are good and tight. Make sure the cab to engine ground is in good order.

If everything checks out., Unplug the steering column connector, and test for continuity again at the cluster and again at the headlamp switch as you did before. If continuity, that rules out the steering column wiring. But then you will have to unwrap and check the wiring from the cluster connector, the steering column connector and to the fuse panel. Not fun.

If you do not have continuity with this test, check the steering column connector closely for crossed wires. Sometimes the wires here can get crossed if the turn signal switch has been replaced. It is sometimes nessecery to remove the wires from the connector, to replace the switch. If this passes the test, you will have to remove the steering wheel, and remove the turn signal switch in order to inspect the wires in the column.

 

ok i searched the white/blue wire...nothing, but there is a new twist on the issue...

so i was testing a few things and discovered that almost every wire on the inst. cluster plug and on the light switch have very good continuity with ground...im guessing this means there is some kind of power touching ground somewhere?

i double and triple checked all my grounds under the hood...i unplugged basically everything from the main harness under the hood and rear harness and still had continuity to ground

i poked around for a good while in the dash and came up with nothing....i am truely lost...

 

You will have continuity to ground through the bulbs themselves.

Nothing unusual.

you need to check for continuity between the White/Blue and the Blue/Red wire.

Which you did, and found continuity. That means there is shared power in those two wires when there isn't supposed to be. They are not supposed to be connected.

When you find the problem connecting those two circuts together is when your lights will work right.

Unplug things in turn untill the continuity problem goes away and then that section is the problem one.

I know it's difficult trying to explain these things in words. We are close to the problem though.

 

the white/blue wire runs through the dash to the RH side and out through the firewall...i traced it the whole length and even out under the hood...and there is no issues with that wire, thats the weird part

i even traced the blue/red wire and found no issues with it...

i unplugged everything i could and still had the problems which means it must be in the main harness..but i didnt see anything...ill check over everything again tom. to make suer i didnt miss anything

 

Yes, that suggests main harness alright. And they can be a pain. the thing is, the problem can be smaller than the width of a fingernail, so could easily be overlooked. And the problem could be under the black plastic wrapping, so it may need to be removed. Which is a pain for the main harness. Been there done that. But melted wires inside the main harness, causing a short, may have no outward sign, because of the black wrapping.

 

81-F...what would you think of doing an old fashion 'wiggle test' while having continuity? If the meter is reading a 'short' and the harness is 'grabbed' and twisted in different small deflections--unless it was melted, this might yield a result-- move the harness in small steps and see if the continuity changes it's resistance? IE: Two wires rubbed together in a very small fashion, to the point it's not clearly something anyone can 'see' with the naked eye?...Might show up if the harness is gently flexed? If an area is found where the ohm reading gets stronger or weaker? That would point to issues?

I've been following this one closely, and have to give a well done shout out--my actual job is a video game repair tech, and wiring issues can be the biggest headache ever.. (go figure? From being an auto tech years ago--to a repair tech for arcade games LOL)

S-

 

Very good suggestion, I was thinking of the same thing if nothing obvious could be found wrong.