Lost Tail, Parking and Dash LIghts

[Stinky]

I hooked up a tow-dolly to the 720 yesterday and the dolly's lights were acting funny.  I didn't have all the lights, and when I hit the brakes, some of em came on, and some of em went away.

 

Tonight, I go to fix it, and I notice that I lost parking, tail, and dash lights....And the rear lights are still messed up.  I chase the lights down to a bad ground.  There was about 2" of bad wire in the ground wire.  I splice in a new wire and still nothing....nothing on the PU that is.  The dolly appears to be acting fine....w/o tail-lights.  It has turn and brake-lights and they seem to work fine.  Neither one has tail-lights.

 

Oh, I am pretty sure that when I started, I had no brake lights either.   

 

When I turn on the Hazards and Turn Signals, the bulbs flash just fine.

 

So, here is my theory....the dolly's lights were grounding back in to the truck's wiring, somewhere, and that has screwed something up.  

 

The PU's lights...(dash, parking and tail) where do they ground?  Through the switch?  

 

Do you have any ideas?

 

I pulled the fuse...the top is hot.  When I plug in the fuse and probe the bottom, it is hot too (the fuse is fine).

[Snohomishdatsun guy]

Wow, I had practically this same write up just the other day. 

 

Found some bad wiring on the rear harness. Repaired the wires reconnected and tested. It was still blowing the fuse. After digging around under the dash I found a pinched hot wire. Repaired that, but before I tested it again I checked the cabin light and found a bad bulb. Replaced the bulb and tested. No blown fuse.

I had two people tell me to check the cabin light. Now I'm not sure replacing that bulb did the trick but it can't hurt. If anything look at light wiring and door switches for corrosion. 

 

Keep in mind that the lights you have out are all on the same circuit. Plus there is more on that circuit as well.

 

Including the cabin light.

 

 

[datzenmike]

Power is sent through the light switch to the bulbs and to ground.

 

If dash lights are out then it's the fuse or the light switch in the cab. This is fuse 13 from the left or 3rd one in from the right side of the fuse box. This fuse is for side marker, running, dash and interior lights. Touch a test lamp to both exposed terminals on the fuse. It should light on both.

 

I assume the dolly is connected to a spliced in trailer plug??? These are almost always installed by amateur home mechanics and almost always a failure point due to improperly crimped connections with poor long range protection from the elements. If the dolly has signals then at least the signals and the ground return is working, but if the truck does not have signals then the ground on the rear lights isn't working. I would start with the trailer plug and look for salt water corrosion, wires twisted together not soldered, wrapped in duct tape or even masking tape, twist on wire connectors. I had one once and cut 2 foot of crumbly blue copper wires out and replaced them.

[Stinky]

I'll re-read your posts later tonight.  I was working on it today.  The switch.....grrrrrr.  Working w/a test light, I had voltage going in, but nothing coming out of the switch.  I used Radio Shack Corrosion Coating on the back of it.  The can says that it cleans also.

 

We'll see if I gained anything on my headlights.  My switch is really marginal, but I can't find one to replace it with.  The switch is fairly complex as this is one circuit, there is also the low-beam and high=beam circuit (2 of em).

 

I have fooled w/the switch before.  

 

I had the inside light...I think.

 

The dolly lights....bad ground....about 3" of bad wire. in the plug, in the ground.  

Quote

 

 

[datzenmike]

Parking, clearance, license, dash are a separate circuit and fuse. Headlights have their own twin fuses and switch

[Stinky]

Well, the lights worked for a few days.  Today, I am driving and smell something overheating....then I see smoke.  It is coming from the crack, between steering wheel and the stuff on the column....then the lights stopped working again.  I still have the dome light.

 

GRRRRRR!!!

[datzenmike]

Split the clam shell around the light switch and try rinsing out the switch with spray can contact cleaner/lubricant. NOT brake or carburetor cleaner!

[Stinky]

I did that again last night....it lasted under a minute.  I did it again this am.  We'll see.

 

I am etiher going to Jerry-Rig it, or buy a switch from Autozone.

 

Anybody know....does King-Cab=Power-Steering which equals Tilt-Wheel (my truck).

[Stinky]

BTW, 20% coupon on the Autozone website for a $147 switch , right now.

 

PN sw1687