My brother in law has an '03 Hemi which was just about blown, he bought an '04 Hemi from a rollover, we got it in but it won't start, has no spark to the plug wires.

There was one connection different from the two wiring harnesess, we cut the wires and spliced them together, color to color.

We tried using the computer from the '04 but it still doesn't fire.

We are getting fuel, just no spark.

Looking for some suggestion's.

Thanks.

 

If you used your 2003 wiring harness, you shouldn't have any issues. What "connection" are you taking about...have a picture of it? You should be able to use all of your existing 2003 wiring, PCM, TCM and just swap the engines only.

You definitely can't use a 2004 computer with 2003 wiring harness, and the 2004 wiring isn't going to match up with your 2003 C130 plug. If you're wanting to convert to 2004 pcm and wiring, then you have a lot more work to do.

 

Can't get a picture at the moment.

We aren't wanting to convert to 2004 wiring, we stripped the '04 motor of the wiring harness and used the 2003 connection's, one of the plugs on the '04 motor didn't match the plug on the truck's wiring harness but I'm not sure which one.

 

The 2004 has an EGR valve which the 2003 would not have a plug for. I guess if it is a late 2004, it could have the newer throttle body, which your 2003 plug would not match up to. If that is the case, maybe use your old 2003 intake and throttle body, etc. I could be wrong, but I thought all of the sensors were the same.

Where is the plug?

 

It's on the driver side up by the firewall. It was a big connector.

Everything else is plugged up.

 

About how many wires would you say you had to splice together? You don't know where on the engine it is?

 

I'm afraid I don't know what it plugs into, the bro in law wired it up. I wanna say 8 or 10 wires on top and bottom, so 16 or 20 altogether.

 

Ok, hard to tell then. Scanning for codes might give a clue, but you're going to have to figure out what it is.

 

Yeah, next time we get to the truck, which will probably be Saturday, we gonna have the code reader by so we can see if the computer's talkin' to us.

I think we might try a coil pack from the old motor (which we KNOW starts and runs, just near death) and see if that does anything. We pulled the plug wire from the #2 cylinder and used the old screwdriver test method, and had no spark.

Being that the truck the the '04 motor was in was rolled I wonder if the electrical system could have gotten fried and toasted the coil pack(s)?

Since these don't have a distributor what's the best way to backtrack a no spark issue, as one would on a motor with a distributor?

Sorry to sound dumb, Hemi's are like a foreign language to me.

 

I think I figured out what connector you guys cut up. There is a connector that connects the fuel injector harness to the main harness (C106) and they are different from 2003 -> 2004. Actually there are 2 plugs, but the other one is the same.

I think the easiest thing to do would be to revert the plug on the main 2003 harness and if not use the entire intake manifold from the 2003, at least take off the 2003 injector harness and install it on the 2004 manifold. That will get you in business.

If there is no hope for your old connectors (hopefully you left a little wire on there), use the images below to match up the pinouts. Using colors only will not help you here, especially in different years. Also the 2004 is setup for EGR which your 2003 doesn't have a phyisical connector for, nor does it know how to control it.

2003


2004