Hi guys...hope you can help me trouble shoot this latest problem. I bought an LED tailgate light bar for my 98 Ram 1500 and noticed it needed a flat 4 prong hook up which I didn't have so I bought the adaptor too (just had the regular circular plug). Before permanantly attaching the light bar, I hooked it up to test it and it didn't work. So I tried it on my other vehicle and it worked fine so I knew it was my truck. Upon investigating, I noticed that with the lights on, I don't have any power to the license plate lamps either. I DO have power to the tail lights though and no other things are 'not working' in the truck. I checked the fuses in the cab and they were fine. I located the fuse box near the battery but really didn't know what to check there. I crawled underneath to check the wiring and found one license lamp wire was loose when I tugged on it, the bulb came out of the housing, still in the wire....it had been burnt out and actually had melted the plastic casing around it. I thought maybe it's kinda like Christmas lights...if one thing is out on the circuit, the rest of them would fail too. So I went to the parts store and got another bulb but that didn't help. (I still have no idea why that bulb melted the plastic, the other one looks fine). The parts guy didn't have any idea as to why I have no power to the license lamps and hitch but still have power to the tail lights. He said if I can't find out where the problem is in the wiring, he could re-wire it directly into the working tail light line. Is that a good idea? Any thoughts on what I need to check to get to the bottom of this? I have only had the truck 6 months but I know the license lamps worked when I bought it because I followed it home while my husband drove it. I've never tried to use the hitch plug for anything yet. It's illegal to drive without a lighted license plate so I'm not going to take it out at night til I fix this. Thanks!!!

 

Don't assume there's no power to the circuit ... it could just as well be a bad ground. Got a meter? Pull the bulb and check for +12V on one contact (power on, of course). If that's there, you need to ring the other contact to ground (with the power off). One of them has to be bad ... it's a very simple circuit.

 

I had the same issue with the license plate lite. I just removed the old 1 and went to O'Reilly's and bought a new 1 $3 I think it was. As TMS stated get a circuit tester and click the alligator clip to a good ground,cut the old melted piece off leaving enough wire from your wiring harness to splice the new one on, turn on your park lamps ( less pull on the battery ) and touch the pointed end to each wire( from the wiring harness), i think one is brown and the other white.you should light up the tester if it's getting power, if so then splice in the new piece and plug in the new bulb then insert into holder.
I by passed my trailer hookup because I initially had all working lights but eventually lost running lights and only had turn signals and brakes. There is a fuse in the fuse box under the hood that's for trailer something or other. it's not the typical blade like fuse it's a small square box one with a clear window on top. Mine had blown so I replaced it and solved the problem but then it happened again this time the problem wasn't the fuse but the actual round hook up. Wal-mart and O'reilly's has a simple bypass kit that takes 5 minutes to install. Go under the bed of your truck and unplug the square harness that connects the wiring from the front of the truck to the tail light assembly. The kit plugs inbetween the 2. then do the same for the other side. Then plug your light bar in the flat style 4 pin plug that;s attached. You can still use this for trailer pulling as well. I'll try to get you the part no. but it takes only 5 minutes to do.

 

Thank you...I do have a meter and I will try that tomorrow after I get off work! O' Reilly's just opened up in our town last week so I can try them. I went to AutoZone first because they had the light bar (O'Reilly was out of stock) so they were where I went back to about the burnt out bulb (any idea why that happened? Why it was so bad it melted the plastic??) I brought the wire and bulb in but they said they didn't have a replacement for the wire, just the bulb. They said I'd either have to go to Dodge to get the license lite wire or hunt for one at the junk yard. I was surprised at that and was just gonna rig it to attach to the the melted housing somehow. I'll see if O'Reillys carries it. By the way, TMS Bill, I laugh my butt off everytime I see your picture about where you stash your cash....SO true!!! Thanks guys!

 

2 words for what they told you B%LL SH*T. Go to O'Reilly's you will fong the little bulb thinga majiga it the section with the bulbs and fuses and electrical wires. Also you can by pass the 2 little L.P. lites and go to Autozone and get the L.P. Hyper White Lite. It's a mini lite bar about 6 inches long that your mount above your L.P. and splice the wires into any of your tail lite wires that is hot when you turn on your lights. You will still have plenty of room for the light bar to mount below it.

 

yeah, I thought that was BS too. Thanks!

 

those little lamps eventually get hot and the plastic holder gets weakened over time so a combination of both will melt the bulb housing. Sorry I'm just answering you on that one I was just amazed at how A.Z. could be so lazy and unknowledgeable. With O'Reilly opening up they won't be the only dog at the chow bowl anymore.

 

check the fuse to the tail lights also, in the fuse box, they are seprate ones for the truck and the trailer, if it blows you wont have power to whatever is plugged into the trailer plug....

 

Problem resolved....though still don't know what caused it. This has taken up SO much of my time and has been very frustrating, but I thank everyone for their advice here. I tried replacing both bulbs but ended up having to replace both wires too (had to wait for O'Reilly's to get another one in stock, apparantly they only stock one at a time??? Weird). After that, I still had no power to the trailer plug...I checked every fuse and even replaced the one under the hood that said "trailer" just in case, even though it appeared and tested fine and I used my meter too. Just no "juice" to it for some reason and I didn't feel like hunting down the the wiring when MSCC8541 had suggested using the by-pass kit (post above) that sounded like the way to go! I got that installed and went to test the light bar with it...I had power! Yeah! Not so fast....When I had the lights on, it was a solid bar, but it stayed solid and the turn signal feature didn't work, nor did the brake light feature. ARGH! I went back to AutoZone where I'd bought it and I backed up to the front door so they could come out and check it but the guys were already standing at the door and said when I put the brake on as I was backing up, the right turn signal on the light strip was activated (not on the trucks tail light itself though). This made no sense at all. The bypass kit wires right into the tail lights and they worked fine, I did the wiring right, so why was the light bar acting so odd?? I asked if they had another in stock and we could try another new one to narrow this down. If it worked ok, I'd swap out for it. If it did the same thing, I was stumped. Well...new one did the exact same thing. No one at Auto Zone could figure it out. I returned the damn thing and almost gave up completely, then I decided to see if O'Reilly's ever got any back in stock (they didn't have any at first which is why I bought from AZ) They had one (49", not the 60" I wanted but I wasn't picky at this point!) and we tried it first in the parking lot. That one worked just fine...SOLD! I installed it right there and it's functioning just fine still. I'm SO glad this mess is over with.....but I'm still curious about two things. What in the hell made that first (and the second new one just like it) act so oddly?? It was a Bully brand one. And the other thing is that when I was splicing on the plug for the new wires for the license plate, let me tell ya, not only was the plastic all melted around the bulb, but the copper wire for the pos. end was all blackened too....what could have caused such an overload? Should I be worried about electrical problems? And why wouldn't that much power/heat have tripped the fuse?
Again, thanks to everyone for your advice and support...I'm so glad I found this forum!!

 

Just brainstorming here ... if the lead between the two bulbs (is there a lead between the two bulbs?) was shorted to ground, the circuit would draw twice the current it was designed for, although not enough to blow the fuse. Over a period of time, the bulb, burning hotter than it should, would melt its housing, overheat the power wire and eventually burn out.

Thoughts ...