2001 Ram 2500 360 4x4 w/nv4500 and trailer tow package. Single cab base model.

My free time being very limited these days, it has taken me a couple months to complete some long overdue repairs, picking at them an hour at a time here and there. Heater core and evaporator core replacement, hvac box reseal, dash top replacement, timing cover and intake manifold gaskets, repairing the corroded grounds under the battery tray, among other things. I just about have everything back together, but function testing shows my brake lights, reverse lights, and interior dome light no longer work. I'm curious if anyone here has had their dash completely out. I've got a few lonely connectors I can't recall undoing, and I can't seem to remember what they go to, if anything. Currently I can't see what might plug into them. It's very possible I pinched or tucked connectors up to some unseeable spot while moving the dash assembly around. It's a bear to move by yourself. I'll lean it back again if I have to in order to find them. I'm just looking for some guidance on which direction to look for the mates to these.



I assume this one has to do with the brake and reverse lights given its tag. I just want to make sure it's not solely for a trailer brake controller. This should be connected to something, right? Anybody know where it's other half dangles from?


This 2 pin branches off the steering column harness and hangs right behind the dash kick panel crossmember below the steering column. Anybody know what its for?

This is the back of the head light switch. Should there be a connector here? Or is this only if you have a fog light option on the truck?

Thanks for any advice. Lesson learned. Take pictures, especially if you're not re-assembling any time soon. 😅

 

First one is just for a trailer brake controller
second one is not used
Third one is used for fog lights

 

Thanks! That eliminates those! Now to find my yet undiscovered screw up. 😄 I'm open to any suggestions.

I meant to mention before. The fuse for the brake lights is good.

 

Test for ground and power at the rear light sockets. Look under the dash and make sure the brake pedal is indeed pushing the plunger on the switch

 

the pedal is indeed pushing on the switch. In fact, i had to install a new brake light switch because I broke the old one when slinging the steering column around. More on that later.

So I got home from work around 2am on the balmy 25° morning and decided to go outside and see if I could make any progress.. checking for power and ground is a good suggestion. But I know it's a power issue because the brake lights are a 3 wire setup. The turn signals and tail light work, and they share a ground with the brake light. Even so, I decided to remove the tail light and confirm.

Rolling around under the truck i noticed this ground strap from the bed to the cab seemed to have checked out a long time ago. So, i fixed that.

In my hand is the tail/marker/turn signal light. The wires are from left to right : ground, tail light, turn signal/brake light. I confirmed no power to the brake circuit and the reverse circuit with a meter.

While putting the truck into reverse while parked, i saw the reverse lights blink on quickly, then out as i dropped the gearshift fully into reverse. Fiddling with this a few more times i was able to duplicate it. Which tells me this is likely a reverse light switch problem instead of a wiring problem.

After confirming my suspicions with a meter, I headed back to the new brake light switch, where I noticed something I hadn't before.


This little switch on the brake light switch body was turned at a 45°angle, instead of vertically. After flipping it to the vertical position, the brake lights worked perfectly. 🤦‍♂️ Just thoght id give an update for future readers. Problems solved! Thanks again!