Hello there. I hope this is the right section for this kind of post. I hate to have it be my first but I really need your help. Basic situation: 1999 Dakota, extended cab, originally a 5.2 and now a 5.9 liter. Manual transmission. I need to get my girlfriend's truck inspectable (Vermont state inspection) and the only thing failing it at this point is the reverse lights not working. The driving lights (small clear lights next to the headlights) don't work as well. They haven't worked in quite a long time by her account, though I'm wondering if they've ever really worked since she bought the truck. The Haynes manual is nigh useless and the owners manual is missing though I doubt it would be that helpful.

There is a security system installed where you have to hit the unlock button on the remote entry fob to be able to start the truck or hit up on the electronic unlock button on the door once you're inside but we've never had a problem with this, not sure if it's factory or not.. There's also a tow package that I believe is aftermarket and appears to be non-functional but I'm not familiar with towing systems at all and don't even know where to begin investigating it. I'm planning on clipping all of the wires at the back of the truck and capping them off just to prevent shorts as the socket back there is in pretty bad shape from corrosion. And finally there is an aftermarket Rally fog light setup running through its own relay/fuse box in the engine bay to a switch under the dash though the bulbs themselves seem to be burnt out.

What I've done: I replaced the NSS/reverse switch with a new one even though the original seems to be in fine working condition. The bulbs are fully functional. Using a multimeter I've determined that there isn't power at the bulb sockets nor at the fuse block position (#2/15a) and I've gone through the rest of the fuses and scrutinized them and replaced anything that looked suspicious. I don't really have the option of taking the whole dash apart right now though I've tugged on the wire going to that position (black with green tracer) on the fuse block and it doesn't seem to move at all. Found it going into the power block in the engine compartment and did the same thing. At this point I'm assuming that it's a problem with that wire somewhere between the power block in the engine bay and the fuse block OR it's in the power block itself. The easiest thing I can think to do is to pull the wire from the big plastic block connector and run power directly from the battery's positive terminal to the wire and see if that fires up the lights or if I'm getting any voltage at the fuse position under the dash. I don't believe this is a grounding issue as the other posts I've read on here regarding reverse/brake light issues that end up being a ground show intermittent functioning and other things have issues since they're all tied into a ground near the back of the frame.

Questions: Is there another switch involved on a manual transmission aside from the one mounted to the side of the housing that, mentioned somewhere in the Haynes manual, is a combination park/reverse/NSS?

Are there any relays that have to do with the reverse or driving lights? I know the fuse position under the dash is listed as both but I can't find anything in the power distribution center that mentions it at all.

Any suggestions or ideas on what/how to check would be greatly appreciated. I understand with the tow package and fog lights it's a nightmare. I just need to get power running to those lights and the only way I can think to do that at this point is to clip the wire behind the fuse block and run one straight from the battery with an inline fuse or wire both reverse lights to a toggle switch and the battery completely independent of everything else. I'm avoiding that option since it's more time and money I really don't have right now. I'm including pictures of the covers and the PDS and fuse blocks so if you see anything odd, feel free to point it out and don't hesitate to request more pictures. I'll get them to you as quickly as time and daylight allows. Thank you. - Colt

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the one thing that comes to my mind would be a blown trailer relay. wiring on the 2nd gen dakota is a freaking nightmare.. haha.. i own a 2000 dakota. and rebuilding it mainly cause of rot, but i digress wiring on these things are a kick in the ***.. with a side of pain in the d**k.

dumb *** question.. did ya check the bulbs in question.. but re reading, u not only checked them but also checked the line voltage.

if is just the marker and reverse lights, there is, i belive a reverse light sw on the transmission. the marker lights, could be a blown headlight switch. could be a melted wire.. bad ground. could be a lot of things.. start with checking the headlight switch... the haynes manual SHOULD have the wiring diagram for the headlight switch..

let me know what ur results are, i am quite curious as to the cause

 

A couple more questions. I'm fairly certain that it's the wire between the PDC and the fuse block that's causing the issue but can someone confirm for me what color/tracer that wire is supposed to be? I think I found it in the Haynes manual but I'm not very familiar with automotive wiring diagrams. It doesn't help that I found another diagram online that seems to conflict with it.

Also, do the headlights need to be on for the DRLs and reverse lights to activate? I wouldn't think so but want to make sure. Thanks again.

 

On the backup lights, did you check for power on both sides of the fuse? The ignition switch needs to be on when testing. It's a brown with light green tracer wire.

It's just a backup lamp switch on you manual transmission, not park/neutral.

DRL's? Is it a Canadian truck? They weren't standard in the US for 1999 and no you don't need the headlights on for the reverse lights to come on.

What "driving" lights are you referring too? You have headlights and fog lights (below on the valance), the small clear area next to the headlights does not illuminate. The yellow parts below and on the outside of the headlight assembly do for park/turn.

 

Thank you for the reply. I'm more familiar with Jeeps and Toyotas and since I don't have the truck's manual I had to assume that those extra clear spots just beside the headlights were DRLs and they were installed since the inside of the fuse block cover shows them listed as the same fuse as the reverse lights. I thought it was brown/green but wanted to make sure. I've triple checked that there's absolutely no power at the fuse block position however there IS power coming out of the lead for the brown/green wire in the PDC in the engine bay.

If I can find the brown/green wire behind the fuse block I think I'm going to snip it and add removable connectors to it and just run a line straight from the position in the PDC to it for the time being and sort it all out later. I know this is less than optimal but I don't have the time and weather right now to pull the entire length of wire to determine where it's broken at. The casing on the exposed part inside of the PDC was pretty brittle.

 

Do you have power windows? Do they work? They share the same feed as ONE side of fuse #2. You are positive you have no power there, with the key ON. Testing both sides of the fuse to a good clean ground?

Have you pulled the fuse out? Maybe the connection is corroded. It's pretty unlikely to have a junction block failure. You can always pull the connector on the back.

The feed for the backup lights does not go through the PDC under the hood. Just because there is power there it has no bearing on what you're seeing at the junction box.

From fuse #2 in the junction block (fuse box) the brown/green tracer wire passes through the big white connector C200 up above your feet and then to the backup lamp switch and then the lights to ground.

 

The power windows work fine. I'm confused though, and forgive me for my ignorance, but how can the power windows use "one side" of the fuse? I thought that with vehicle fuses power comes in one side and goes out the other and continues on to whatever device is being powered. Part of the problem with figuring out what's going on behind the dash is, as far as I can tell from the Haynes manual, you have to remove the steering wheel and the entire plastic dash surround just to access that area. I could be wrong since Haynes really isn't the best for this.

To answer you questions: I've tried several different new fuses in the #2 position in the junction box. The original didn't look corroded, nor do any other fuses in there, but I wanted to be on the safe side. I've checked all of the fuses I tried for continuity with a multimeter and they all passed. I've been checking for power in the junction block by touching the two probes from the multimeter to the respective contacts inside of the fuse position. On things that are working I get a consistent 11 and change volts, and from the #2 position I get absolutely nothing. By a good ground, do you mean another fuse position or part of the frame?

How does the power for the reverse lights not go through the PDC? There is a brown/green wire going into the large white connector in the PDC. The prong for that wire under the connector is hot but the wire end itself (disappearing into the bundle) isn't at all. The wiring diagrams in the service manual definitely show some part of the reverse light system going into the PDC, "C106 (IN PDC)" but I'm not familiar with the symbology involved.

Sorry if I'm being frustrating but my background is more mechanical and household electrical than vehicle electronics. If you want I took pictures of the diagrams I'm looking at in the Haynes manual that I can post up or email to you depending on the board rules for posting material out of a printed manual.

 

The junction box is like the electrical panel in your house. You have one 12 volt input, in this case it is switched by the ignition switch, and then it "divides" off into multiple, smaller fused, circuits. In your house you have the 120 side off each leg being distributed to each circuit breaker.

While one wire comes from the ignition switch (run position), it feeds multiple devices such as the power windows, ABS controller, and the reverse lights, by basically being connected to one side of each fuse. See the attachment. Notice how on all those fuses have one side from the ignition switch. Therefore, on each fuse one side should be hot.

By the ground, I mean a good clean ground, such as a screw that goes into the body. There is a "real" ground location near the junction block.

Just because you see wires with the same color code does not mean that they are the ONLY wires with those colors. The feed to the brake light switch originates from INSIDE the cab, not under the hood. It then goes through that big white connector just behind/above the brake pedal, to the switch on the transmission.