hemi wireharness cut/splice ?

Personally, I've chosen to go the MS3 route. As others have already chimed in the pros and cons I can tell you by the time all is said and done, MS3 is only a little cheaper than reprogrammed unit from Hot-Wire. The key benefit to MS3 is that you have complete control of the fuel and spark in your motor. For those wishing to change cams, run forced induction, staged nitrous, or anything out of the ordinary, MS 3 offers a level of tune-ability beyond the factory harness.

That being said, you can modify a factory harness and get it to work in a classic muscle car. There are a couple of keys to making this work.

1. Get EVERYTHING from a single donor. Motor, trans (if your going that route), and every harness you can lay your hands on, un-cut, un-molested. Personally if I were going to go this route, I'd get a truck motor from and 05 or 06. Get the under dash harness if you can as well as the under-hood harness. The factory gas pedel can only be used once, so simply get the wiring up to the pedal.

2. Determine if your engine utilizes a SKIM key. The skim key is an anti theft device built into the key. Think of it as an electronic hand shake that must occur between the key and the computer before the car will start. No Hand Shake, no start. If the car is skim key equipped get the key, and the dash wiring. You'll need to incorporate some of this into your wiring harness.

3. Be sure to copy down the VIN number off the car or truck you can't fiddle with the computer without the VIN. Think of it as the combination to the lock.

4. Get a copy of the FACTORY service manual, they are available online cheap.

5. Print out all the wiring diagrams. (You might want to buy a laser printer. Ink Jet printers cost about 22 cents a page to print vs. 4 cents for a laser printed page, YOU'LL be PRINTING A-LOT)

6. Trace each and every wiring coming into and out of the PCM (power train control module)

7. Slowly but surely mark the wires you THINK you won't need. Wire by wire eliminate the wires. What I'd do is get a pin extraction tool and pull the wire, and simply tape it off until your SURE you won't need it.

6. Test fire the engine. Does it run?

7. If it runs, plug in a code reader, and check for error codes. If your code free, you can remove the wires from the harness, simply unwrap the harness, remove the wire and set it aside. Don't cut it you might need it later.

8. A note about "reprogramming" most reprogramming simply involves using the factory service tool to switch off a bunch of options in the computer. You can buy a factory service tool on E-Bay for around $4000.00. (now you know why, Hot-Wire charges 250-400 to "reprogram" your factory computer.

Finally, here's a guy who did modify a factory wiring harness TWICE. Read through his build and you'll get some, though not all the info you need to do the job.

http://www.forabodiesonly.com/mopar/showthread.php?t=53074

Regards,

Joe Dokes