Updated to add: I'm assuming that you had the alligator clip on ground when you probed the socket and got light. If I'm wrong, disregard what follows and post a reply to let me know. Back to our previously scheduled deprogramming:

Okay! The buzzer indicates that the switch circuits are intact from ground G300 up through the switches to Joint Connector 6, which goes by way of splice S309. S309 is where the yellow wire that provides the ground side of the dome lamp leaves the circuit that we know works. Assuming that the test light illuminated on the other side of the lamp, we're down to finding the broken conductor between the lamp socket and S309. (S309 is hiding behind the left kick panel. Consult the FSM for its location and the other stuff you'll need to know to find the run of that yellow wire.)

The next thing to check: Hang the alligator clip on battery positive, and probe into the conductor at S309 (which should have a 20 gauge yellow wire exiting it). If a door is open, the test lamp should illuminate, and if it does all you've left to do is find the broken yellow AWG20 conductor between that splice and the lamp socket. If the test lamp doesn't illuminate my logic is borked and we need to back up a step to call me an idiot. Otherwise:

What we're going to do now is to isolate the section of wire that contains the break by probing that conductor and keeping track of the point furthest from the splice that yields light when probed, and the point furthest from the socket that yields dark. At each step, we're going to update our note of which point is which -- got light furthest from the splice here, got dark furthest from the socket there. To make it easy on ourselves because we're going to drink beer and ogle the women walking past so are sure to get distracted, we're going to use a piece of black tape to mark the darks, and white tape to mark the lights. Now:

We got light at the splice, so put the white tape at that point. We got dark at the lamp socket, so put the black tape there. Find the midpoint of the run of that yellow wire between the splice and socket, and stab it. If you get light, move the white tape to that point. If you get dark, move the black tape there. Continue along stabbing midway between the tapes and moving the tape that indicates whether you got light or dark, and the two tapes will get closer and closer together until you get a short enough run between them that you won't mind cutting it out and splicing in a repair.

Edited again to add more: On the off chance that you've got multiple breaks, fixing just one won't make the dome light work. That kinda sucks because it causes a moment of panic, but just stab that damn wire again at the repair splice and see the light where you know you had dark before to prove to yourself that you really did fix a broken wire. Put your white tape there, and your black tape back up on the socket. Alligator clip to battery positive. Stab the center between the tape. You know the rest.

Then, with the repair(s) spliced into place, just button it all up and groove on the photon emission for a while.

 

That poor wire is gonna bleed to death!!!

 

It's already dead!!!

The hot ticket is to use a test light with a needle tip probe, and dab a tiny amount of liquid tape onto the stab wounds to keep air from reaching the copper inside to cause corrosion that makes new breaks years later. Newer insulation will close the hole well enough if it's a tiny one, but it never hurts to dab a little goop on there.

PS: Over the span of a ten foot run, you're likely to only stab the conductor in four or five places before you're down to a segment short enough to replace. First at five feet, then two and a half, then one and a quarter, then at eight inches, and finally, four inches. Most of the time that's enough, unless you're really very close to a terminal connection that you can't replace for some reason (like not owning a pin pusher and connector pins).

 

Haven't heard from you in 6 days...just wondering if you'd made any progress. Every time someone posts a problem fix, the angels sing. Well, maybe not that, but the rest of us appreciate it, especially those who were helping. Some, like me, are gaining some good knowledge.

 

It'd be hard to fault a guy for thinking long and hard about taking the advice of a stoned hippie whose only known qualification is that he sometimes uses the same internet as you.

Imagine telling that story to the service writer at the dealership after frying all the electronics in your truck: Well, what I did was, I hooked the ground wire to the positive terminal of the battery, which really didn't seem right to me, hooking the ground to the positive, and then I poked the pointy end of the test light through the insulation of this wire in several places, which didn't really feel right, either, but some random stoned hippie on the internet told me that that's how I could fix my dome light without paying you guys. And then later he joked about it being maybe not too bright to just take the advice of some random stoned hippie on the internet, but I went ahead and did it anyway. So maybe he wasn't joking after all.

Who ever wants to be that guy?

 

Sorry guys I got caught up doing a heater core in my camaro aswell as tracing a roof leak on my house soni haven't played with the ram any, no dome light just failed alittle in comparison to the roof leak lolx and the stoned hippy doesn't scare me in the least! We may be one the same stuff by the end of all this?

 

Can't say I didn't try to warn ya!

But, seriously, we've pretty much got it down to one frotzed wire and just have to hunt down the break or breaks in it to make the photons fly around again. I'd be happy to see even one of these electrical troubleshooting threads end in resolution, too.

 

Is the dome in question in the rear of the cab or the front which would be part of the over head map lamps? And did you try ground the circuit.

 

Rule #1: Start with the appetizer. You miss all the fun by just showing up for dessert.

 

That's nice. I read all the information. And I haven't seen any fix so far. I just trying find out if there an open ground circuit or a loose ground at either side of the kick panel. If you want bust my chops, that's fine. I'm game. I am currently a dodge master tech and have been since 1989. The questions I may ask is help to find the problem. I try to keep it simple. Or K.I.S.S