The reverse backup light feed is pin 6 C3 of the Fuse Box. It sends power to the transmission which switches to the fuse. Don't know what causes it to send the power. The main distrubution box has been known the have problems too. Did you download the service manual. You know for testing some of the connectors there are special test connector so you don't directly probe the connector.

 

Running light issues are probably the PDC = fuse box to you and I.
Known issue with corroded internal printed circuit boards and their earth returns.
There is a how to on here some where about jumpering the park lamp rely which forces a supply to the park lights. I think jumpering pins 30 to 87 forces this supply. If the lights then work, it's the PDC as the park lamp relay isn't getting an earth return from the PDC/fuse box.
This method proves beyond doubt, the integrity of the park lamp circuit if they come on.
A lot of other issues are also caused by this PDC. So look into it is my advice.
Al.

 

Thanks guys, I appreciate the ideas, keep 'em coming! :thumbsup:

The hood didn't get damaged, original hood (replaced the front plastic grill which was cracked), under-hood area wasn't left exposed.

It was run into a ditch and just trashed the axle, transfer case, bumper, and fender. I replaced the front bumper ($200), both headlights (aftermarket, only the left one was damaged) ($125), aftermarket tail lights ($100), rear center upper brake light ($25), left fender ($50), front axle ($1,000), and had the transfer case rebuilt with a donor shell ($400), then had the whole truck re-painted the original white ($1,100) and had a bed liner put in ($75).

We rang out the radio yesterday, it's getting power to both leads (constant 12V hot and ignition 12V when the ignition is on), so I suspect the replacement "good" head unit off eBay was actually bad. Going to try an aftermarket radio once I get this thing legal to drive and registered (rear running lamps and reverse lamps working and exhaust on - it's cut after the cat so no O2 sensor is throwing the CEL).

Today's hit list is the transmission output speed sensor to see if we can get the speedo and odo back and ring out the brake lights and ground wires and see if we have power to the running lights since we have power at the fuse box and maybe it's just a bad ground wire for the rear running tail lamps.

The relay (and its power supply) for the running lamps is good. That same relay controls both the front amber lights, the top amber lights, and the rear running lamps. I checked the voltage at the supply pin (good) and also swapped it with the starter solenoid relay (which obviously works because I can start the truck) and you can hear it click when you put it into place with the lights turned on and all the running lamps light up EXCEPT... both tail light running lamps.

I've been doing some reading and it LOOKS like the reverse switch is built into the transmission's solenoid pack (awesome, thanks Dodge, I'm not replacing that), so I'm going to look for a wiring issue FROM the Reverse output wire going to the fuse box. If I put the truck in Reverse with the key in the ON position but truck not running it should still send the signal that the truck is in Reverse from the solenoid's reverse light switch inside the transmission out to the fuse box reverse lamp fuse. If I don't have voltage at the output pin of the reverse switch going up the wire, we'll go from there. Overdrive works along with the gear position indicator now, so it appears the transmission is GETTING power to it from the main distribution center under the hood, I'm just not getting reverse light power TO the fuse box reverse light fuse which then would run to the tail lights IF it was sending the signal AND the fuse was good (which it is).

Does anyone know for certain if the transmission has a separate output reverse sensor like all the OTHER Dodge trucks before now or if, indeed, it really is built into the entire solenoid pack?? That would be a terrible design from a consumer standpoint, but great for Dodge for additional aftermarket repair costs. :/

And yes, I have the service manual in PDF format. I went through a few pages and it doesn't give enough information. You'd have to have the service manual AND the electrical schematic of the entire truck (including WHERE those wires are located on the frame in relation to other components which the wiring schematic alone doesn't have) AND the breakdown of every switch and solenoid inside the transmission to put this entire puzzle together and I haven't been able to get all of those and cross-reference. With the fuse not getting power, it's hard to track down.

 

Honestly, I seems you're dumping more into this truck (time and money) than what it's worth.

 

Nah, I picked it up for $2,000 so I'm still way in the black for what it's worth. Right now it's just irritating.

I can't find the damn transmission speed sensor. I found the Input and Output speed sensors but those are for the TCU for shifting and shifting works fine. The book says it's in the tail end of the transmission (but it's the ONLY thing in that part of the book that doesn't have a picture) but I don't HAVE a tail end of the transmission because I have a transfer case. 4x4.

So I'm looking all over God's creation for another place, even following wires, and I can't find where this dang thing goes. There are only 5 wire hookups on this transmission that I can find visually looking:

Left side of transmission (Driver's)

1. Input Speed Sensor
2. Solenoid Pack connector
3. Output Speed Sensor

Top of transfer case - 4x4 position sensor

Right side of transmission (Passenger's) - one 3-wire connector at rear, not sure what it's for, but it's connected to something that's not removable and doesn't match my pin connector anyway.

Any idea where the transmission speed sensor is on a 4x4 truck? The only pics I can find for a transmission speed sensor are for a 2WD Ram.... the Haynes manual sucks, by the way.

 

Well, alrighty then. I can't help, but good luck with the project.

 

Thanks for the help anyway.

Gave up on the transmission speed sensor, it's pretty clear that it doesn't exist even though the Haynes manual said it does. I'm guessing since it didn't have a different section for the 4x4 transmission that it was giving generic information for the 2WD version. Probably going to have to take it to someone who actually knows more than just what the Haynes manual does since it's clearly missing information.

The tail lights evidently share the ground. There's 5 wires going to each tail light:

1. Brake Light
2. Turn signal
3. Running Lamp
4. Reverse Lamp
5. Ground wire

Since the brake lights and turn signals work, it's clearly not a ground wire issue or NONE of the lights would work. Since the fuse for the rear running lamps is getting power and the fuse is good and the wire bundle running back there seems to be intact along the frame, I'm starting to lean towards the OUTPUT of the fuse box circuit board which takes us back to... PDC.

In other words, you guys may be right. Hard to believe that the input power on the fuse box would be fine but the output would be messed up. May tap a wire off the front running lamp wire to the rears to at least be able to drive at night until I get something else worked out...

 

The only sensor I find for your transmission is the Input Speed Sensor, which I don't believe would cause your problem.

 

here is the transmission repair manual....

http://www.scribd.com/doc/71324204/6...Service-Manual

 

Does the speedometer come from anti-lock module?