First of all, I'm new to the forum, but I've done a lot of reading on it in the past. I'm usually pretty fair at turning a wrench, and electrical has always come pretty easy for me. I've built/rebuilt cars, trucks and semi's, and I'm in the process of building an Experimental airplane now. I've never felt the need to post anything until now, but I'm coming up empty, so here goes.


I drive a 1999 Ram 3500 Cummins base truck with 369,000+ miles and running strong. I was given an almost complete, power interior out of a 2000, 2500 Sport truck to replace my ratty interior. I changed every wire inside the cab, from the cab lights to the overhead computer console, the seat wiring and the wiring inside the doors and dash. I have it all installed, and working great, but I'm having a few issues. First, the odometer and speedometer don't work now, so I was thinking the computer may need flashed?? Hoping a trip to the Dodge garage could fix that one. Second, I lost my high beam headlights and high beam indicator. Low beams work great, but when I click the lever for high, they barely come on with a low glow, and are slow getting to that point. My first thoughts were a bad ground. I have the headlight switch for the 2000 as well as the original switch out of my '99, and neither makes a difference. I've even thought that maybe the wiring from the 2000 wasn't compatible with the 1999 wiring under the hood?? Dual vs quad headlights..etc. Any thoughts or suggestions would be appreciated. I've read schematics for HOURS, checked all the fuses and relays I could find, and I've pulled the dash several times. I'm just not seeing anything obvious. On a good note, I can have the dash out in about 30 minutes... lol

 

Do the tach and other gauges work ? The speed and odometer information comes via CCD bus messages from the ABS module. There is a joint connector (#7) that ties all the CCD bus devices together. It sits somewhere on the left side of the instrument panel (the FSM isn't very specific). That's where I would start troubleshooting.

For the headlight problem, keep in mind in the later yers the lights are "ground switched". There is permanent power to the bulbs and the headlight and multifunction switch connect the filaments to ground. That makes troubleshooting easy, just use a wire connected to ground and check at various connectors along the wiring if the lights get bright.

AFAIK there were no wiring changes from 98 to 2001/2002 but I don't know everything

 

Run the dash test and see if all the gauges work.

 

Thanks for the reply. I ran the instrument cluster test, and it didn't go as the video. I pressed the trip button, and turned the ignition on, and the CHEC light illuminated. The instrument hands did not sweep, and I got no other indicators light up. What I did get was immediate codes of 950 and 999. Do these refer to an automatic transmission??? My truck has an NV4500, as did the donor truck.

As for the gauges, they all appear to work as usual. Volts, tach, coolant temperature, oil pressure, and fuel gauge seem to be normal. The only indicator light that stays on is the seat belt, and it had done that before the swap. I've driven the truck approximately 50 miles, and no strange readings. I did find that with the Edge unplugged, the truck is a serious dog. I plugged it back in, and left it turned off, and it was back to normal. Truck runs and drives great.

 

DerTruck.............. All the other gauges seem to work as they should. I've driven the truck approx. 50 miles, and it runs good, and acts as it always has. The only issues are the ones I noted. As for joint connector #7, I found it in the FSM section 8W-90 and location was shown on Figure 24. Not to hard to get to, thankfully. I have had several spine surgeries, and lot of metal installed, so I'm not very flexible now. I'll check that connector and see if there's any corrosion or damaged wires. The donor truck only had around 106K miles on it, but the interior and all wiring was removed a couple years ago and has been stored in a garage since. Corrosion can happen fast. I've heard from a couple guys that have made similar swaps, and said they had to have the dealer flash the computer, and the speed and odometer came back to life. That's a bit out of my range of expertise, so I'm unsure of that.

As for the ground on the headlights.......... I'm not sure where to start, other than known grounds, which I know of only 3. 2 grounds on the back side of the dash that go on studs. One towards the center, behind the ash tray, and one beside the fuse box, and there's also a joint connector attached at the lower drivers side kick panel. It's wired from the harness for the power windows, locks, speakers, etc. I will say, the bare metal structure that the dash plastic attaches to, is unpainted, and has surface rust. Possibly a bad connection where the 2 large bundles of wires attach to it. I'll let you know what I find............ if anything. THANKS!!

 

I was out checking out the truck, and noticed that the cab lights did not work. I'm working on this outside, as my garage is full with an airplane in one stall, and a 1953 Chevy Pro Street in the other, so it's difficult to see if all the lights are working. I missed the cab lights previously. I didn't see the ground wire that the original cab light harness had, so I found a ground wire and grounded the cab light harness to the chassis. The headlights worked then, but the high beam indicator wouldn't go off. I also noticed when the headlights worked, the parking lights and clearance lights did not work.... hmmmmm As I was checking grounds, I did notice that the colors of the wires on the headlight switch, did NOT match the colors on the original harness. Another big hmmmmm..... Now I'm starting to think that the 1999 harness and the 2000 harness are NOT compatible.

 

We have both of those service manuals available for download here. Compare, and see if the systems work the same way. I know there were a fair few changes 99 to 2000....

 

I have both service manuals downloaded, and have spent several hours this afternoon, reading and comparing the two. I should have checked it sooner, and I would have saved a lot of time and work. From what I'm seeing, the two years have numerous changes. Not saying it can't be done, but it's not a plug and play situation. I was cruising another forum today and found a thread from a guy attempting basically the same swap. From the last post in that thread, he still hadn't gotten everything working. He had the same problems that I'm having. We'll see how it goes, and where I go from here. I'm getting pretty good at pulling the dash... I'll keep you posted.

THANKS!!

 

UPDATE on the truck............... I decided to remove the 2000 interior cab/dash wiring and go back to the original 1999 wiring. The truck ran good on the 2000 wiring, but no speedo, no odometer, and lots of light issues (probably ground) made me decide to change back. I have a few surgeries coming up, and I wanted to be sure I had a driving vehicle before then. I removed all the wiring, and installed the original wiring, and all lights work great now, BUT,,,, it cranks but won't start.. I feel like I'm out of the pan and into the fire. I could hotwire the VP44, but I'm pretty sure the issue isn't under the hood. I'm pretty sure the issue is inside the cab, dash wiring, as it started and ran with the 2000 harness just a few hours before I changed back I've checked all the fuses, and all looks good. I'm trying all the obvious things first. The blue wire on the ignition switch is the "run" wire, so that's were I've started searching. That goes to the fuse box, #9, I think, and tomorrow, I'll trace from there to the C134 connector and see what I can find. I did run the dash test with all the original wiring, and it went through the test as the video showed, with all gauges working, and no codes found.

Suggestions? Advice? I appreciate the input so far...

 

Der diesel? hhhmmmmm..... I don't know enough about those to do much troubleshooting..... Anything in the service manual for a no start? The engine cranks though, right?