Ok I have been turned down by 2 different Dodge dealers in Wisconsin for help or information on wiring harnesses, wondering if anyone on here might be able to give me some help. I have what I'm told is a 96 cummins stuffed into a 99 Ram body/frame. The guy before me had started the project and gave up on it. I picked it up fairly cheap, knowing full well it was someone elses project, but the wiring has me completely up in fits. I'm told the guy bought brand new underhood/underdash harnesses but I dont know if he got them for the 12v because there are plugs laying all over and I have no working gauges. I have read some posts on other sites and its gotten me no where. I have working headlights, and warning lights on the cluster work (WTS, CEL, ODO etc) but I have no tach speedo or fuel gauge. I know the harness under the cab to the back is not plugged in, because the front part has a single plug, and the back part has 2 plugs and they dont go together so im assuming thats why no fuel gauge, but any help in the rest?? Thanks!

 

Without knowing which harnesses, which PCM, what transmission or a slew of other things, nobody here can help you. Man, I really hate to come off like a dick, but "there are plugs laying all over" and "because the front part has a single plug, and the back part has 2 plugs and they dont go together" are too vague and don't tell us squat. No tach could mean the PCM is out, problem with the alternator circuit, CPS is shot, etc. Is it an automatic? How are you achieving overdrive/lockup without a working speedometer?

There's too much we don't know about your truck. There's too much you don't know about your truck. Help us help you.

 

I get it completely, I guess after re-reading it I didnt say anything worth saying. The body and frame are a 99 Ram 1500. The motor is from a 96 cummins, and the trans (auto 47re) is its mate. I have not driven it it, because I am waiting for a TV cable for it...so as far as overdrive/lockup is concerned I havent yet. The harness plug that is underneath the drivers door under the cab.



this is the plug that is supposed to plug into the rear harness (tail lights. trailer plug, sending unit etc) but the harness for the rear has (2) connectors, instead of 1

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Your correct in saying theres too much I dont know about my truck, I just got it last week and have started into it. I apologize for coming off so "newb like." As far as the PCM goes, I do not know for sure what it is from. That I am hoping to find out Monday from a parts place, hopefully they can run the numbers for me.



Please let me know what other info you need if you think you could be any help at all. I'm looking to the guys who know these trucks a heck of a lot better than I, this is my 2nd Dodge, and first Cummins project.

 

Ideally, what you want is the harness out of a '98. As far as I know they are OOP, so if he bought it brand new it probably isn't the right one unless he opened this can of worms years ago. Can you get a hold of the guy? Find more out? Where he sourced the parts, etc? Those plugs look right to me from my time under my own truck, but that doesn't mean they are. The PCM doesn't though, I'm pretty sure the harness plugs into it on the bottom.

 

I tried to do something similiar one time with a 94 dodge. i did not try to change the engine, but the dash board rather. my old one was cracked to hell, and i had a good dash out of a 98. bolted up good and all the holes matched and everything. then i ran into the wiring issue. The biggest problem is that in a 94, and maybe 96, there is only an ecm in the instrument cluster. In the 98 there is an ecm underhood also. i realize these vehicles are mechanical, so i use ecm loosely i guess. but what little bit of control module differences there are between the two made it very difficult to make the swap. I ended up finding a new dash top for the old one and went back together with the original dash. If you could find the dash/instrument cluster out of a 98 you would be in good shape i think. things should plug in then. but im only guessing.

 

Negative. '94-'96 PCM is under the hood, secured to the firewall with 3 screws on the passenger side. Mind-dump everything that guy just said.

You want to do exactly what JBear said. Find out which harness you have, if you can. Post a picture of the service tag on your PCM and I'll tell you what year it is. We'll go from there.

 

I went to the Dodge dealer by me, and they said they wouldn't run it to find whats its from. But the guys at the service counter are a bunch of dinkholes.

 

What do you mean by OOP? As far as I can tell it is a brand new harness. I figure its the wrong one. I know its tough to help with such little information and not seeing it first hand but I appreciate any help you guys can give. Unfortunately I cant, I do not know who it is, and the guy I bought it from is NO help at all tracking the one who started it down. I have tried multiple times, so its all my mess now. I have no problem pulling the motor and harnesses and starting over, was just trying to see if it would be possible to make whats in it work. I tried running the serial on the PCM and I'm getting VERY mixed results, and none are coming out right. Can of worms it is!!

 

The part number is 56040849 and it's out of a 1996 Ram 3500. That's the computer you want. Now we need to figure out what wiring harness you have.

 

Thats good to know, where did you come up with that? I got everything from a 96' ram to a 2001 dakota on the interweb search I have what I believe was the "take out" harness from the 99 ram 1500, but again I came up empty on a search. The numbers on it are P5602178A3 871 T-CW1322860065. I was unable to find the tag on the one thats IN the truck now. Where does a guy look for that? Thanks you the.beard for the help man!