Modifications! Oh Yeah....

Hey gang,

Need a little help here. I’m planning on doing some major mods to the truck but need some major help in the electrical dept. First off, I love my truck! YES I DO!! But the engine, not so much, LOL. I’m planning on chucking the original 4.7L and 545RFE, an in its place installing a 4BT/47RH combo. Now I’d like to keep the gauge cluster, steering column, and air bag system if possible.

So my main questions would be. If I was to yank out the current ECU, and transmission computer, would the truck still be operational? I know/think the air bag system has it's own computer that it runs off of, so I think I'[d be safe there. Basically I’m just going to be using the wires that come off the fuse block in the engine, since the 4BT don’t have spark plugs and all or major sensors and switches to run. The other thing would be trying to hook up the 47RH to the speedometer. The trans is out of a 95’ Ram 2500. I’m sure I’ll think of more questions than answers and I’ll keep you guys posted and updated on the progress.

But any help, suggestions or comments would gladly be appreciated!



Blessings,

Ron

You really have no idea what you're in for lol. Someone on here years ago blew the 360 in their 2002 and swapped in a Cummins 5.9 12v. Took him like 3 months to try and get it to even fire the factory way and like another 6 months to get the gauges and everything to work correctly.
Your PCM does double duty for both the engine & trans. You may not be able to use your existing key switch since that sends a signal to the PCM, which takes in certain inputs, if it has them then it allows the engine to start. If not, in most cases it will not allow the engine to start. I would try disconnecting the starter signal wire & the PCM and see if you get signal voltage when you hit the key. Bypassing everything is easy, but just yanking out components and hoping for the best won't fly if you want everything to work correctly. The cluster gets all of it's inputs through the bus (via PCM, etc). Having a 2005 puts you right at the last pre-CAN bus year for the trucks so things are just about as electronically complicated as they can get without the fly-by-wire from a hemi.
So the SRS should be unaffected unless there is speed sensor input (I don't believe so, but I recommend you go to the DIY section and download your service manual to check diagrams and confirm). RH & RE swaps are done all the time into early 3rd gens so that shouldn't be an issue at all. Once you get past getting it to start (and converting your fuel system, etc etc etc), you will probably be able to drive it around just with no gauges.

I had this crazy dream when I was in high school of having a 68 Charger that I would keep a 318 in for daily driving and then on Friday after work I would have a 426 hemi that I would have ready to swap in using quick disconnects. Come home, swap motors, grab a shower, and go hit the town. Kind of Green Hornet style.
And then I woke up.
I think my plan was way more realistic than the one time swap you want to do. Just save your money for one of the awesome deals that will be available in the coming months.

Oliver Closehauf said:

I had this crazy dream when I was in high school of having a 68 Charger that I would keep a 318 in for daily driving and then on Friday after work I would have a 426 hemi that I would have ready to swap in using quick disconnects. Come home, swap motors, grab a shower, and go hit the town. Kind of Green Hornet style.
And then I woke up.
I think my plan was way more realistic than the one time swap you want to do. Just save your money for one of the awesome deals that will be available in the coming months.

Click to expand...

My damn engineer brain started going over that scenario and the first two things that occurred to me were the two different trans bolt patterns and front torsion bars/front suspension height with the massive weight difference between the two engines lol. Gotta love dreams.

That was before my first rebuild. That experience woke me up.