Hemi Swap Complete - 2002 4.7 to 2003 5.7
#91
09-18-2020, 07:15 AM
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I am about to change a 2003 5.7 into a 2005 where a 4.7 came from, I was told it could be done but I have to remove the brain and flash it before I install it with the engine? Can anybody give me some info on this? What other problems am I going to run into?
Last edited by Steve Christy; 09-18-2020 at 07:56 AM.
#92
11-15-2022, 09:12 PM
My 4.7 kicked the bucket so I chose to put a hemi in its place. The hemi swap is complete and the truck runs pretty good. It took about 3 months or so, doing a little after work and on the weekends. The holidays made things difficult with much to do. I did this outside in the driveway in the middle of winter in western maryland (truck won't fit in the garage). We got a few feet of snow over this time as well as really cold temps and crappy winds.
I did a lot of research before I bought the hemi. I read damn near every post in this forum and others that contained the words "hemi", "swap", etc. I also got help from 2 guys in this forum. The only oversight I had was the exhaust. I doubted that my 4.7 Y pipe would work out with the hemi manifolds, but it wasn't a show stopper and deep down I wanted headers anyway. They were cheaper than an aftermarket Y pipe/cat assmembly for the 03 hemi, so that was a pretty easy decision. If I didn't go with headers, I could've had a shop fab something.
The most time was spent doing research, waiting for parts, and cleaning up/painting the engine before install. I made sure the junkyard was going to give me everything I needed. However, the junkyard sales guy had a lot less time to talk to me after I paid them. They cut things they were supposed to save, left out some parts, and took FOREVER. I spent more time dealing with these a$$holes than I did the install. Long story short, they paid me for all of the new parts I had to buy plus some, so it turned out ok. And the sales guy was fired for promising me and others too much!
Parts needed for 2002 4.7 -> 2003 5.7
2003 hemi engine w/ accessories - I realize the 03 isn't the best for tuning and has possible valve spring issues, but I was looking for ease of install. I can always go to a 2004 wiring harness later for tuning. I also plan to do the valve springs this summer when it warms up.
PCM + TCM
Both engine mounts
Both Radiator Hoses
AC Hoses - Need both hoses coming from the compressor. The alt/compressor switch sides from the 4.7 to the 5.7 so the lengths are different. I kept the same condenser and accumulator.
Heater Hoses - I bought 2 bulk pieces of heater hose to flush my heater core prior to the swap. I cut them to size to use with the hemi. I will eventually replace them with right ones that are curved appropriately so it doesn't look so ghetto.
APPS - Accelerator Pedal Position Sensor. If you didn't know, this is a little box that mounts under the battery. It has a throttle cable that is connected to the gas pedal and an electrical cable that runs to the PCM. 4.7 had a cable straight to the throttle body.
Air intake - I think the stock airboxes are different, but I'm not sure. I made a CAI from PVC anyway so I just pulled the 4.7 airbox assembly.
Fuel line - Hemi came with a good bit of the fuel line. All we had to do is get a compression fitting to attach it to the one on the truck.
Exhaust - I ended up going with Pacesetter longtube headers + Y pipe (no cats), so the exhaust is new from front to back. Trying out a 3" in/out Thrush welded stainless steel muffler. It was about $40 and think it sounds great.
No SKIM system - I made sure the PCM I was getting didn't have the ignition key security system. As I understand, a $100 and 1 week turn around will take care of this by sending it to a dude to flash it, but I was looking to save dough and time.
I put a new water pump on it just because. Also new pullies, belt, valve cover gaskets, intake manifold gaskets, oil pan & gasket, and I ditched the fan clutch because I already had an e-fan setup. Lots of wire brushing and a little hemi orange paint.
Wiring
Since the 02 4.7 and 03 5.7 both use the C130 plug into the dash, there are minimal differences. I did not have a wiring nightmare like some others, which is why I opted for the 2003. I had to run 6 wires for the APPS and change up the ambient air temperature sensor circuit. I still might have to cross a few other wires, but nothing too major. I have an Evap CEL P0443 that was there before the swap. I think it is the purge solenoid, but not totally sure. My vapor canister is busted up too, but I tried to duct tape it for the time being. Otherwise, I have P0593 Cruise and P0571 Brake Switch A circuit which I will explain below.
Problems
* Cruise Control - 02 4.7 uses a vacuum/servo for cruise. 5.7 is completely electronic. To solve this, I may or may not need new cruise control buttons on the steering wheel. (I had a 2003 clockspring so the buttons might be ok). After that, I just need to get the extra wire back to the PCM. I don't use cruise anyway, so this is not a priority.
* Brake Lights - This is a bigger issue. The tail stop lights are always on when the truck is "on" or running. Brake switch is good, it works perfectly when the truck isn't on. 3rd brake light works well all the time since it is hard wired to the switch and isn't on the same circuit as the tail stops. Maybe completing the cruise circuit will help this issue, not sure yet. I think the FCM is outputting the signal to the lights for some reason.
Otherwise, truck runs good, shifts good, and for the most part, everything works. All of my gauges, lights, and interior controls still work. Thanks to VLSGunner1 & HemiDak-Quad for helping me out. Also to berndog67 for a good thread full of info and to Weedahoe for the service manuals and part catalogs.
Sorry for the super long post. Hopefully it will help someone out.
Pics are mostly crappy phone pics. I wanted to get more pictures, but I was freezing my ace off and trying to make progress. I will upload pics of the engine installed and the actual truck soon. My CAI is still white PVC so I'll get that painted first.
Update 5/2/2011
- Figured out the brake light issue. V30 on the brake switch went to the cruise servo in the 2002 4.7. In 2003 5.7, it just needs to splice into Y135 (FUSED IGNITION SWITCH OUTPUT (RUN-START)) before the I/P -> Dash connector (C219). Brake lights work correctly now
- Cruise Control almost solved. Found cruise switches from a 2003 hemi truck. They have 3 wires instead of 2 like mine had. The 3rd wire on each switch get spliced together, then sent through the clockspring on their way back to the PCM as V38. I added the 3rd wire to the wiring harness in the steering wheel and soldered new connectors to mate it all up. It still doesn't work, but I'm going to look at the diagrams some more and see what I need to do to figure it out.
- I also decided to upgrade the evap stuff to NGC. Got a used Evap Purge Solenoid and wired it up to get rid of the P0443 code I had. I also just got the newer NVLD pump to replace my Leak Detection Pump. Pretty much the same thing, but it has one less pin. I will get it installed tomorrow. At that point I should be CEL free.
PICS
Engine came with some oxidation, but we got it cleaned up pretty good
Attachment 69220
Attachment 69221
Attachment 69222
Had some time while waiting for parts, so I got a little hemi orange on it. Here we just put it on the hoist and are taking it outside to drop in.
Attachment 69223
Attachment 69224
Attachment 69225
Attachment 69226
Attachment 69227
VHT header paint inside and out...wanted coated ones but had to cheap out
Attachment 69228
I did a lot of research before I bought the hemi. I read damn near every post in this forum and others that contained the words "hemi", "swap", etc. I also got help from 2 guys in this forum. The only oversight I had was the exhaust. I doubted that my 4.7 Y pipe would work out with the hemi manifolds, but it wasn't a show stopper and deep down I wanted headers anyway. They were cheaper than an aftermarket Y pipe/cat assmembly for the 03 hemi, so that was a pretty easy decision. If I didn't go with headers, I could've had a shop fab something.
The most time was spent doing research, waiting for parts, and cleaning up/painting the engine before install. I made sure the junkyard was going to give me everything I needed. However, the junkyard sales guy had a lot less time to talk to me after I paid them. They cut things they were supposed to save, left out some parts, and took FOREVER. I spent more time dealing with these a$$holes than I did the install. Long story short, they paid me for all of the new parts I had to buy plus some, so it turned out ok. And the sales guy was fired for promising me and others too much!
Parts needed for 2002 4.7 -> 2003 5.7
2003 hemi engine w/ accessories - I realize the 03 isn't the best for tuning and has possible valve spring issues, but I was looking for ease of install. I can always go to a 2004 wiring harness later for tuning. I also plan to do the valve springs this summer when it warms up.
PCM + TCM
Both engine mounts
Both Radiator Hoses
AC Hoses - Need both hoses coming from the compressor. The alt/compressor switch sides from the 4.7 to the 5.7 so the lengths are different. I kept the same condenser and accumulator.
Heater Hoses - I bought 2 bulk pieces of heater hose to flush my heater core prior to the swap. I cut them to size to use with the hemi. I will eventually replace them with right ones that are curved appropriately so it doesn't look so ghetto.
APPS - Accelerator Pedal Position Sensor. If you didn't know, this is a little box that mounts under the battery. It has a throttle cable that is connected to the gas pedal and an electrical cable that runs to the PCM. 4.7 had a cable straight to the throttle body.
Air intake - I think the stock airboxes are different, but I'm not sure. I made a CAI from PVC anyway so I just pulled the 4.7 airbox assembly.
Fuel line - Hemi came with a good bit of the fuel line. All we had to do is get a compression fitting to attach it to the one on the truck.
Exhaust - I ended up going with Pacesetter longtube headers + Y pipe (no cats), so the exhaust is new from front to back. Trying out a 3" in/out Thrush welded stainless steel muffler. It was about $40 and think it sounds great.
No SKIM system - I made sure the PCM I was getting didn't have the ignition key security system. As I understand, a $100 and 1 week turn around will take care of this by sending it to a dude to flash it, but I was looking to save dough and time.
I put a new water pump on it just because. Also new pullies, belt, valve cover gaskets, intake manifold gaskets, oil pan & gasket, and I ditched the fan clutch because I already had an e-fan setup. Lots of wire brushing and a little hemi orange paint.
Wiring
Since the 02 4.7 and 03 5.7 both use the C130 plug into the dash, there are minimal differences. I did not have a wiring nightmare like some others, which is why I opted for the 2003. I had to run 6 wires for the APPS and change up the ambient air temperature sensor circuit. I still might have to cross a few other wires, but nothing too major. I have an Evap CEL P0443 that was there before the swap. I think it is the purge solenoid, but not totally sure. My vapor canister is busted up too, but I tried to duct tape it for the time being. Otherwise, I have P0593 Cruise and P0571 Brake Switch A circuit which I will explain below.
Problems
* Cruise Control - 02 4.7 uses a vacuum/servo for cruise. 5.7 is completely electronic. To solve this, I may or may not need new cruise control buttons on the steering wheel. (I had a 2003 clockspring so the buttons might be ok). After that, I just need to get the extra wire back to the PCM. I don't use cruise anyway, so this is not a priority.
* Brake Lights - This is a bigger issue. The tail stop lights are always on when the truck is "on" or running. Brake switch is good, it works perfectly when the truck isn't on. 3rd brake light works well all the time since it is hard wired to the switch and isn't on the same circuit as the tail stops. Maybe completing the cruise circuit will help this issue, not sure yet. I think the FCM is outputting the signal to the lights for some reason.
Otherwise, truck runs good, shifts good, and for the most part, everything works. All of my gauges, lights, and interior controls still work. Thanks to VLSGunner1 & HemiDak-Quad for helping me out. Also to berndog67 for a good thread full of info and to Weedahoe for the service manuals and part catalogs.
Sorry for the super long post. Hopefully it will help someone out.
Pics are mostly crappy phone pics. I wanted to get more pictures, but I was freezing my ace off and trying to make progress. I will upload pics of the engine installed and the actual truck soon. My CAI is still white PVC so I'll get that painted first.
Update 5/2/2011
- Figured out the brake light issue. V30 on the brake switch went to the cruise servo in the 2002 4.7. In 2003 5.7, it just needs to splice into Y135 (FUSED IGNITION SWITCH OUTPUT (RUN-START)) before the I/P -> Dash connector (C219). Brake lights work correctly now
- Cruise Control almost solved. Found cruise switches from a 2003 hemi truck. They have 3 wires instead of 2 like mine had. The 3rd wire on each switch get spliced together, then sent through the clockspring on their way back to the PCM as V38. I added the 3rd wire to the wiring harness in the steering wheel and soldered new connectors to mate it all up. It still doesn't work, but I'm going to look at the diagrams some more and see what I need to do to figure it out.
- I also decided to upgrade the evap stuff to NGC. Got a used Evap Purge Solenoid and wired it up to get rid of the P0443 code I had. I also just got the newer NVLD pump to replace my Leak Detection Pump. Pretty much the same thing, but it has one less pin. I will get it installed tomorrow. At that point I should be CEL free.
PICS
Engine came with some oxidation, but we got it cleaned up pretty good
Attachment 69220
Attachment 69221
Attachment 69222
Had some time while waiting for parts, so I got a little hemi orange on it. Here we just put it on the hoist and are taking it outside to drop in.
Attachment 69223
Attachment 69224
Attachment 69225
Attachment 69226
Attachment 69227
VHT header paint inside and out...wanted coated ones but had to cheap out
Attachment 69228
#93
11-15-2022, 09:32 PM
Hate to bring back a 10 year old post, but maybe just maybe the original poster can shed some light on my issue. I am 98% done with my Hemi swap on my 04 model ram but I have the same exact tail light issue. It seems our trucks are wired the same minus a few color changes on the wires. I tried to take the servo wire as noted in the post and connect it to the fused ignition run/start wire but it did not help. I have been messing with this issue for over a week now. I started this swap maybe a week and a half ago, it took my a day and a half to get the motor in the truck and running with the TPS box and all. Now I am just dead in the water, I have tried every wiring diagram I can find, Every pin out of the PCM plugs I can find, I dont understand why the PCM is turning my brake lights on, I have even unpinned all the brake signal wires and cruise control wires from the PCM and tried it to no avail. The truck runs and drives just not legal with the tail lights always beaming soon as I turn the key on. Only seems to do it with the PCM from the hemi. I can plug the 3.7l PCM in and it doesn't do it. I ordered a manual but I wont have it for a few days.
#94
11-15-2022, 09:47 PM
Hey. I'm not really sure offhand what the difference is with your 04 3.7L, but you should be able to find it in the manual. If I get some time, I'll take a look. You can download the 04 manual here: https://dodgeforum.com/forum/3rd-gen...-download.html
Where exactly did you splice the wire, I know it was a long time ago. I cant really seem to find a good place. Especially in the engine bay.
#95
04-25-2024, 06:27 PM
im wanting too do this same swap on my 02 any advice? was it most bolt in/ plug in play mines the areas you had too splice as well as the ease of the install? im trying too gather as much information as possible before dropping some money so hopefully you can shed some light being that you pulled it off