Another magnum swap thread

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Marksman

Marksman

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Alright.. I've looked everywhere and have yet to find the information that I, and I assume others, are looking for. There are tons of write ups on swaps focusing on the physical swap. I can handle that part, but I'm more concerned with the wiring aspect.

I've seen Magnum Mopar's harness and it's a beautiful piece, but with my current poor college kid budget, going that route is out of the question. What I would love to find is a list or diagram of what wires need to be removed from the harness, and wind up with something like a 4 wire hookup as is the case when you modify a LS harness.

The engine I want to swap is a 318/46RH out of a 93 Dakota. I have multiple Mopars so this wouldn't necessarily be going into an A-body, but the wiring would obviously be the same other than slight length differences.

I guess what I'm attempting to start here is a thread to compile any and all information you guys have regarding wiring these things. The lack of good information on this is the reason that full factory swaps are virtually non-existent. It could easily be as simple as swapping an LS.
 
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I'm gathering stuff to put a 5.9 Magnum into my raggedy old beater truck, and like you, have been searching for answers to my DIY wiring harness conversion. Mine will be the OBD2 style, where yours is OBD1. Even though I have commented several times that I would be willing to PAY for a simple conversion schematic, the experts aren't willing to sell me one. Rather make a killing than a living I guess? I dug Waaaaay back in this section, and found what I think will be a tremendous help to me, so maybe you can find something back there too. The thread that helps me the most is on page 15, and it's StreetDaks thread on putting a Magnum into a 73 Swinger. Good luck to you in your search. I think on the OBD1 stuff, you really only do need like 4 to 6 wires to feed the ECU/fuel pump, etc to make it run. Post a schematic if you make or find one. :thumbsup:
 
What I did on my OBD1 harness in my Scamp was got on Alldata and found the pinout for the 60 pin plug for the ECM. Then un-taped all the wiring and started seeing what wasn't needed. Your harness will have things like headlight wiring in it, which obviously you don't need. I got it stripped down to just 2 or 3 relays and fuses in the underhood fuse box (for fuel pump and A/C). Once it's all done I ended up with two power wires that actually connected the harness to the car(and a couple grounds that were in the harness) power for the computer and power to the fuel pump.

I just did the same thing on an OBD2 harness last month. It would have ended up being just 2 power wires again, but at some point I accidentally removed the power to my relays in the underhood fuse box, so I just added that wire to my computer power wire. I tested the harness and started a 5.2/auto that is setting on my garage floor!
 
Thanks for the replies, guys!
JD, I'll definitely check that thread out. When I find (or make one) I will be sure to post it.

Dragbaron, I have a place that I can go to access Alldata so i'll do that. The stuff I was more concerned over whether to keep or remove was like for the evap system, other emissions stuff, etc. and keep the check engine light off.

I would like to eventually come across schematics for both OBD1 and 2, since OBD2 has better diagnostics and are a lot more common. I'm not amazing with wiring but maybe I'll just pick up a couple of harnesses and do some trial and error until I get it figured out.
 
You're welcome. I'm going to stop by the little small town dealership where I bought my Dodge diesel truck, and see if they will let me look at a FSM for a 98 3500....which is what my 5.9 Magnum came from. I have every inch of the underhood harness, including the ECU and fuse/relay box. Thanks for letting me hijack/piggyback along here....lol.

Dragbaron.....thanks for the encouragement! Did you remove the wires in the OBD2 harness that went from the ECU to the gauges? What about the OBD2 hookup port inside the cab?
 
I'm sure they'll let you look at it. If they have an electronic version, see if they'll print the page off. A friend has access to a 94-97 2500 with a salvage title but it only has 88k miles on it. He would like to swap the 360 from it into an 85 d250 so i'll be learning OBD2 wiring as well. I'll probably be able to go to where I can access Alldata on Thursday, so if you aren't able to get what you need from the dealership I'll gladly get it for you. I'm also going to get the pinout for a v10 truck too to see how difficult it'd be to modify one of those harnesses.

I would think you would remove all of the stuff for the gauges, since they are probably different resistances. The OBD2 port is only like a 4 wire hookup, so you'd probably want to keep it for the diagnostics.

Also, Piggyback on here as much as you want. My goal is to have a bunch of people (or at least a few with good info) post on here so we can get this info confined to a small space.
 
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I have done numerous swaps using the obd1 into jeeps it comes down to 7 wires once you thin out the harness. its been a few yrs since ive done one but I still have all my notes. Ill dig around and can forward them to you. Im currently planning on doing an obd2 swap into my 65 dart using a 00 5.9 and 46re
 
I have probably 100 hours into this one here, so i would appreciate it being used for personal use only. I would like to market it eventually when I get it fully refined, but until then, I will share my version. The car runs with the wiring as seen here. I have not got it on the road, but that is due to the chassis not being finished yet.

This was starting with a 5.9L auto from a '98 Ram 1500. It was drawn in Visio, the .jpeg version you see here is not as clear. The big boxes to the left are Bussman ATM fuse and Fuse/relay panels from Del City. The right side connectors are the ECM. The blue and green bard in the middle are my bulkhead connectors going into the passenger compartment through the firewall, also from Del-City.

68wd 10102016 dist.jpg
 
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Seems it won't let me upload it full size. Go to my Photo Garage "67 Charger's garage" I put it in a .pdf. blow it up to 200% or so and it should be plenty useable...
 
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Thank you, 67Charger and 5.2jeep!

67, I will definitely be looking that over! Thank you! And no worries, I have no plans of making money off of doing this! I plan on using for personal and helping out friends.

5.2, I'd still love to see your notes since they're OBD1.

Thank you both!
 
Ive replaced my laptop since I initially done it to my jeep 8 yrs ago. all my old files are backed up on an external harddrive so not sure how long it will take me to find them. however I did a writeup on it on jeepforum.com and did post a lot of the pics and such on there I used the eng harness and pdc from a 94 grand Cherokee but the dodge ones are similar. its actually a fairly simple swap, most time consuming part was just the thinning out of all the unneeded garbage. I used the grand pdc and wired all my add ons thru it ie.... light,winch,oba, etc. I will locate and post them tho. I do have diagrams for a grand Cherokee on this laptop if you need them.
 
This isn't going to be a swap that is happening immediately, so take your time on finding the files.

Ill definitely look over on the jeep forum. I'm not sure if the diagram for the Cherokee would help or not, but it might.

Thanks!
 
Ok. Thanks!

EDIT: Do you know if there's a way to search for usernames on that site? Otherwise ill just scroll through each section until I see a post by you.
 
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havnt been on there in awhile but yeah I believe you can
 
5.2jeepyj said:
havnt been on there in awhile but yeah I believe you can
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I too will be putting a mag360 with OBDII and overdrive trans in my 1973 dart sport some time this year. I will be making my own wiring harness. I am going to see if I can use the computer to run aftermarket gages. Like engine temp, oil pressure etc. Sorry if it has already been asked, but did you have to get the computer reflashed after you deleted all the emission wiring? are you running the down stream 02 sensor? I would like to run headers on mine. thanks Mopar65
 
I haven't done the obd2 swap yet, I'm making my own harness also, on the obd1 the computer doesn't run the gauges, my understanding is obd2 you you run your gauges like normal just will end up with 2 senders. and no I will not be running the down stream o2
 
I've looked and cannot find your username on the Jeep forum, even when using the member search tab. I'll keep looking though.
 
67Charger said:
Seems it won't let me upload it full size. Go to my Photo Garage "67 Charger's garage" I put it in a .pdf. blow it up to 200% or so and it should be plenty useable...
Click to expand...
I went to your photo page and nothing comes up
 
Yea looks like I found me a 360 mag to swap over. Is a 2001-2002 Dodge Durango with the 360 a good swap ? I also want to use the overdrive trans.
 
Mopar65, if you go to the page he told you to go to and look on the right side of the screen, there will be a download option. Click that.

I think it'd be a good swap, especially with the OD.
 
Marksman said:
Mopar65, if you go to the page he told you to go to and look on the right side of the screen, there will be a download option. Click that.

I think it'd be a good swap, especially with the OD.
Click to expand...
 
I haven't thought much about gauges, so I haven't read up on it much, so this isn't definitive. From what I've read looking at other things, the gauges in the '01 Ram use the CCD data bus and don't have direct feeds from the sensors or the PCM.

If this is correct, it means; 1. There are no gauge wires to remove from the harness. 2. In order to use the existing setup from the truck, the CCD data bus will need to remain in place and the truck instrument cluster will need to be used.

Short of backwards engineering the messages from the PCM and building your own circuit board to convert the data to something an aftermarket gauge could use, I don't see a way to do this other than with the factory cluster.

BTW, best I can tell, if you do want to run the factory cluster, the CTM will need to be in place. It appears from my reading that the CTM and PCM are the terminators for the CCD data bus and a lack of either will make the bus useless. Not certain that the CTM/PCM doesn't require input from other modules, only that both are needed in order for the circuit to function.
 
I should add that the above is for an '01 Ram. Not certain how the earlier OBD2 setups function, nor if the Dakota/Durango/GC are similar.
 
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