Here is what I think about this problem. First, you can try replacing the bulbs, but it is not very likely at all that all of the bulbs in the radio, AC/climate control head and the right side of the instrument cluster all went bad at the same time. Since you bought the truck used, you have no idea if they all went out at once or just one or two at a time over a period of time. This sounds to me like the bulbs are all probably OK.
First thing to check is to remove both kick panels and check the ground lugs there. There are ground lugs on bolts with multiple black ground wires on each one bolted to the metal surface of each kick panel. Remove the nuts and take a wire brush to the connectors and the metal lug surface itself. Clean it all down to bright shiny bare metal and reinstall the ground lugs and nuts. Dodge grounds nearly all of the electrical components in the cab of the truck to the connectors in the kick panels. A bad ground could very well be the cause of the light bulb problem.
The illumination circuits that you are having trouble with are all powered on the same circuit together and it is protected by fuse #9 in the interior fuse panel. It's only a 5 amp circuit, dash light bulbs do not draw much current. Check the fuse for corrosion on the legs of the fuse and also on the connectors where that fuse plugs into the fuse panel. I doubt the problem is the fuse though, if it were the fuse then none of the dash lights would work at all.
Then disconnect the negative battery cable, so you don't cause any short circuits or other problems while checking out this next part. You will need to remove the plastic knee bolster panel from under the driver's side of the dash, or if it is possible remove the fuse panel from the side of the dash. However you do it, you need access to the back side of the interior fuse panel. Looking at the bottom (the narrow end) end of the back side of the fuse panel there are two plastic wire connectors. One has 16 wires on it, the other has only five wires on it. The 16 wire connector is the one you want to look at. Unplug it from its molex connector on the back of the fuse panel. Check to see if there is any corrosion on the connectors, cut or chafed wires or anything else out of the ordinary. If it all is OK, plug the connector back in and reinstall the fuse panel.
If you have a volt meter, the easiest place to check the illumination circuits will be at the cigatette lighter or the wire harness that plugs into the radio. You will have to remove the dash anyway to check either one. The wire you want to test is solid orange. Check at the radio or lighter socket to see if there is 12 volts on the orange illumination wire when you turn on the parking lights and headlights. If there is 12 volts there, then you probably have a bad ground somewhere or a corroded ground wire or loose/broken/corroded ground wire somewhere between the back of the 16 pin connector on the back side of the fuse panel and the right side of the dash. If there is no power at the orange wire you tested then there is an open circuit or bad wire/loose connection somewhere between the fuse panel and the right side of the dash.
The type of bulb Dodge uses in the dash does not dim down over time like a regular filament bulb. I am not sure exactly what type of bulb it is, I replaced the 3 bulbs in my own AC/climate control head last year, they all looked like LED's to me. I know they cost me about $2.20 each. But the bulbs either work or they don't. They do not go dim over time, and that is one reason why I do not think you have a problem with the bulbs. This sounds to me like a bad ground or corroded wire connector somewhere in the dash of your truck that is causing the lights on the right side of the dash to either not get a good ground or it is causing way too high of a resistance and not letting the bulbs receive enough 12 volts positive current. Either one of those conditions would cause a dim bulb.
A lot of the accessories in your Dakota rest with 12 volts on one side of the circuit and the operation of the accessory is controlled by regulating or varying the ground that the accessory receives. Dakota's can be susceptible to bad grounds and they cause a lot of problems. They can also take a lot of patience and time to find where the problem is. Good luck and let us know how it turns out.
Last edited by 01SilverCC; 08-31-2011 at 11:10 PM.