2nd Gen Non-Engine/Transmission Test running lights at headlight switch

[BKeence]

I am trying to fix my running lights on my 01. (Electrical Woes post).



I pulled my headlight switch to test it but I cannot figure out which pins are for the running lights. The pin out diagram does not list the running lights. There are 14 pins in one spot and the 2 seperate. I think the 2 seperate are for the driving lights.



One more question... are the fog lights the clear lights in the bumper? I thought they would be called driving lights if they were clear.





Thanks!



Brian

 

[Thomas]

... are the fog lights the clear lights in the bumper?...

Those are the OEM fog lamps.

You need to look at the wire connected to pin #1 on the headlight switch (16 gauge BK/YL). If the fuse blows only when the headlight switch is turned on, you have a short somewhere in that circuit between the headlight switch and the clearance/marker/identification/license plate/parking/tail lamps - lots of possibilities.

 

[BKeence]

Thomas it blows as soon as I turn on the running/parking lights. Which pin are they on?



Thanks!



Brian

 

[Thomas]

All of the things I listed (clearance/marker/identification/license plate/parking/tail lamps) get their switched +12 volts from a single source - the Black/Yellow Tracer 16 gauge wire I mentioned. All of those lamps should not be lighting. I assume the fuse you are blowing is 20 amp fuse F in the Power Distribution Center. If any of the lamps I mentioned are lighting or if it's a different fuse that is blowing, let me know. I think it will be easier to chase down by looking at the fasteners you have installed (Electrical woes!).

Good luck.

 

[BKeence]

You are correct about the lights that are not working. I have since made a mistake and tore the light switch apart. I have learned it is a very simple design, very very hard to put back together. --- Fact I have given up and ordered a new one from autozone for $39. 00. It will be in tomorrow. I did find that little lights are removable, one is a clear light and the other a green led. Both could come out by removing the back of the switch. I don't know if you could ever find a replacement bulb but they DO come out.



If you or anyone would want pics of the inside of the switch just let me know and I'll take some. 2 ball bearing that make the switch CLICK in the off/parking/headlight positions is the BEAR to get back together. I think I could mess with it longer and get it back together but my patience has definately ran thin for tonight.



Okay, I'm going to go test the black w/yellow tracer and see if it shows a short.



Thanks again Thomas for the reply.



Brian

 

[BKeence]

Hey Thomas,



I checked pin #1 black w/yellow tracer with my digital meter on continuity and it sounded a short to ground. Would it show a short because of the bulbs? Is there a different way to test the wire?





Brian

 

[Thomas]

Hey Thomas,

I checked pin #1 black w/yellow tracer with my digital meter on continuity and it sounded a short to ground. Would it show a short because of the bulbs? Is there a different way to test the wire?


Brian

If fuses still blow after replacing the headlight switch you have a short to ground.

With the black w/yellow tracer removed from the switch you have quite a few filaments providing a path to ground from the pin #1 connection. The fact that the circuit is protected by a 15 (not 20) amp fuse suggests to me that the resistance from all the parallel cold bulb filaments is quite low and might look like a short to your meter.

You could always remove all the bulbs - not an easy job and it wouldn't locate a short other than show there is a short somewhere in the circuit.

With a Factory Service Manual you might locate junctions in the circuit after the black w/yellow tracer, open the junctions and isolate the short.

If the problem actually showed up after installing items on the truck, I think the easiest thing to do is look at everything you have disturbed.

 

[BKeence]

FIXED IT!!! Long reply!

I still had the short after replacing the switch. I removed every bolt I have put in the last few days, nerf bars, front mud flaps, tool box bolts... . STILL SHORTED!!!



I soldered up a clearance light with leads long enough I could lay it on the ground. That way I could see it from anywhere under the truck. I wiggled and shook wires all the way up the frame, I even let the spare down to check where the wires run under it. I decided I was going to cut the black/yellow wire under the cab to isolate the trouble somewhat. I pulled the wires out of the loom and was trying to get enough slack to work and cut it when I found a nice plug right behind the front wheel. I unplugged all the wires that lead to the back of the truck. As soon as I did it my low fuel dinger started sounding.



I looked over at the test light on the ground and it was still burning -- So I figured the problem lies in the front of the truck. Just for fun I stuck in a fuse and turned on the lights --- Cab lights and front parking and dash all light up and stay lit. Hmmm! I hooked up the homade test lamp and it still lights. You are right Thomas, enough ground through the bulbs to make the test light burn.



Now I know the problem IS in the back half of the truck. I decided to unhook all bulbs. I was able to unplug every light from under the truck. Much easier than removing the bulbs. I didn't know there were that many plugs back there!



I tested the black/yellow with my meter and it does NOT show short. I plugged the harness back in behind the front wheel and turn on the lights... cab, dash and front parking lights all light up again. Now I'm getting somewhere! I started out plugging lights in one at a time until I finally blew the fuse - Darn 3 bar light on the tailgate. I have not figured out exactly where at on the light yet. I'll work on that tomorrow after work. I finished plugging in the rest of the lights. Oo. ALL is GOOD!



I did break a prong off one of my marker lights on the dually fender. I called the parts house, they don't show one in their book so it must be a dealer item. I'll run by the 5 Star tomorrow.



Thomas thanks for your help. I sure thought it would have been in something that I added to the truck in the last couple days!! It's sure nice to know about the plug behind the front tire on the drivers side - I could help isolate in the future.



On a good note - I did spend 39. 00 on a new switch so now the little background lights work on the dash!



G'day!



Brian