My truck has developed a problem that I can't figure out. When I bought it a couple of months ago the back-up lights worked. Since then I've replaced the dome, map, side marker, and front turn signals with LEDs. I've installed a Tridon EP-27 flasher and done nothing else to the electrical system.

The other day I noticed that neither back-up light is working. I tried different bulbs and even put the original turn signal relay back in and checked the fuse (it was good) but they don't light up.

Any ideas? As far as I can tell all other electrical is working without a problem and no other lights are having issues.

 

From your profile I got it a new body style 2004 auto trans.

When you checked the bulb, did you check the pins on the back of the fuse to a know good ground ( and you are talking about fuse #14 correct ) ?

Did you check the bulb connector for power to a different ground ( i.e. the trailer tow adapter ) ?

Did you check the trailer tow adapter to see if the reversing circuit worked on that ?

 

Yes, new body style auto trans...

Yes to fuse #14.

No, didn't check against a known good ground. I'll have to get out my multimeter and find the instructions for it to make sure I'm checking it correctly...

I'll try checking this afternoon. Thanks.

 

I'm having this same issue with mine right now too! I've checked everything! No power was going to reverse lights and I read the sensor on the side of the trans was bad since it has reverse lights sensor built into it, replaced it and nothing! If you find the issue let me know and I'll do the same if I find out

 

Will do. I didn't get out to check anything since it was raining so I'll have to see what mother nature has in store for me then. Kinda sucks that they're out. I just bought some LED backup lights, too.

 

No power from the DTR ( Digital Trans Range ) Sensor, how about power to it ?

You cut the circuit in half, and got nothing from half way to the end.
This meant you needed to pick half way from the start to the middle or slowly work you way back to the start to find the error, not replace the middle.

BTW : You did have the key in the run position when you were checking for power, right ?
- The fuse is only hot in the run position.

 

I haven't been able to get into it too much with the rainy weather but during a break in the rain I was able to pull both taillights outs and check continuity at the sockets (which was good).

I checked the voltage at the sockets with the power off (0.0 volts), with the key in the power on position (.23 mV), but no change from the .23mV when reverse is engaged.

Any ideas on what the voltage should be?

 

Got to love this rain. Made driving to Maywood this AM for my 1st appointment real fun.

The reverse lamps should show +VDC as in what the battery has ( -10% still good ).

So you should see at least 12.1 VDC when in reverse.

Put on your diver's mask and get your snorkel to check the DTR voltage when you get time

 

Finally tracked down my problem. Turns out the wiring on my trailer got messed up either due to being put in wrong or from getting messed up when being towed. In my case, the number 10 fuse (20amp) was the culprit. It's one of the fuses for the trailer lights. Taking my trailer back to where I bought it so they can fix it.

On my Expy the trailer turns and brake lights would work but not the parking lights... On my F150 the trailer lights all worked but it ended up blowing that fuse.

Anyway, tomorrow I'm putting the LED back-up lights in and leaving the trailer without power until I get it fixed....

 

Ahh yes. My camper has left me without lights before. Took me a while to figure out why it would only happen on vacations