Harness Help

[delfinomuro]

Wasup guys. So I’m working on a project that will be a “C10 KILLR”. I have a 87 Dodge Ram and will be doing a HEMI swap, 4th gen HEMI. I just bought the motor and harness and ECU was included, out of a 2012 Dodge Ram.
Was wondering if anybody on here can make the stock harness to where I can use it on my truck. So I guess get it “made” and using the stock ECU. Wanted to check here before I started calling these big companies that will charge an arm and a leg. I’m also aware of FAST. Worst case I’ll go with FAST.
My intention of the build is to primeraly race C10 squarebodies with LS swaps. Want to show them boys what damage the HEMI can do.

 

[Richard Cranium]

Here ya go.............

 

[Gone]

Here ya go.............


View attachment 605868

Lord have mercy!

 

[2quick]

Here ya go.............


View attachment 605868

Is that right hand drive?

 

[Richard Cranium]

Is that right hand drive?

No, the negative was flipped.

 

[Bobzilla]

Get wiring diagrams for the truck your engine and harness came out of. All you have to do, on any fuel injection swap like this, is keep the wiring used to actually run the engine (and transmission if using the electronic teansmission that goes with that engine). Then, just supply the power and ground feeds to that donor harness and clean up all the connections.
The real question, and one I have not seen an answer to yet, is whether or not that factory ECM will run properly without the security system of the truck connected. That is the main reason for everyone using the aftermarket standalone controllers.

 

[JimKueneman]

Here ya go.............


View attachment 605868

Cut the red one....

 

[Budnicks]

try the Pro-Touring Retso-Mod forum here
there's a few guys that have done gen 3 hemi swaps
that may be able to give you a hand/help or some tips/clues

hopefully you can get the ol' org. harness
& computer out of the car/truck what ever it came out of
or another of the same type etc.
I'd think that'd be one of the easiest ways to adapt it
not sure how much stuff is stand alone

not my wheelhouse

maybe the guys at www.madelectrical.com @ Mad Enterprises
may be able to help too, not sure thou

good luck

 

[Bobzilla]

If you have the original security module (WIN module in 2008 Ram, have not looked in newer models) and the key that goes with it, you can wire all that in and it will work.

 

[delfinomuro]

Get wiring diagrams for the truck your engine and harness came out of. All you have to do, on any fuel injection swap like this, is keep the wiring used to actually run the engine (and transmission if using the electronic teansmission that goes with that engine). Then, just supply the power and ground feeds to that donor harness and clean up all the connections.
The real question, and one I have not seen an answer to yet, is whether or not that factory ECM will run properly without the security system of the truck connected. That is the main reason for everyone using the aftermarket standalone controllers.

Thank you! I do have the harness and PCM out of the same truck that had the motor. I guess what I’m trying to do to avoid paying $1000 for a aftermarket “plug n play” is using the same harness, like you mentioned. But question is, can I still use the factory ECU after “cleaning up” the harness to what I just need. I’d rather pay somebody $$300-400 to make it work instead of $700-$1000 for an aftermarket one.

 

[delfinomuro]

try the Pro-Touring Retso-Mod forum here
there's a few guys that have done gen 3 hemi swaps
that may be able to give you a hand/help or some tips/clues

hopefully you can get the ol' org. harness
& computer out of the car/truck what ever it came out of
or another of the same type etc.
I'd think that'd be one of the easiest ways to adapt it
not sure how much stuff is stand alone

not my wheelhouse

maybe the guys at www.madelectrical.com @ Mad Enterprises
may be able to help too, not sure thou

good luck

I’ll definitely post there!!! Thank you! I always wondered, is my a hemi considered a Gen3? It came out of a 2012, and I always had second thoughts if the 09-current are Gen4s.

 

[Bobzilla]

You can definitely use the original harness to make your own standalone harness, and you can definitely use your original PCM. Think of it like any other smaller electrical installation, such as an aftermarket ignition. Most of the wires you keep run from things like fuel injectors, ignition coils, and engine control sensors, and the other end of those same wires mostly run into the PCM itself so they can be controlled. You leave those wires alone; don't cut them.
The reamining wires are things like power and ground feeds to the PCM, power and ground feeds to things like O2 sensor heaters, ignition coil powers, etc.
Once all of these are identified, you simply run your grounds where they need to go (some on engine or body and PCM straight to battery negative post, or as close to it as possible). Then run battery power feeds through fuses (same amperage as the truck had) to a new fuse block or buss bar. Then run ignition feeds the same way, through fuses, to the appropriate ignition switch circuits.
If you layout your harness on the engine, connect all sensors, coils, throttle, PCM, etc, you'll see there is not much left. There is likely one large connector on the end where it would have connected to the truck. That connector will have the wires you need for power and ground, as well as data lines to hook up a data link (DLC) connector. Now your almost done.

 

[Bobzilla]

If you still have access to the truck that PCM came out of, try to get the original WIN module and key fob. The WIN module is the assembly that you actually stick the key fob into for starting the truck on a 2012. You'll need that to make it work as a standalone. It communicates security information about the correct key fob to the PCM, and the PCM will not start the engine without it.