Wiring questions

-
Elwood blues

Elwood blues

Well-Known Member
Joined
Aug 12, 2018
Messages
66
Reaction score
5
Location
Wisconsin
I have alot of questions that I need cleared up. I got an 05 5.7 hemi going in my 71 Scamp with a 727. I'm looking into all the wiring and stuff and it is my weakness, but I'm trying to learn/understand it. I know I need a harness but that's about it. I was looking into a mega squirt, but I got confused on weather if i get one do i still need the ecu out of the truck i pulled the engine from or do i need just that. Also do i need an ignition box with it as well. Does the harness connect to the 727? I have more but I'll have to think of them as I go. Pretty much looking for someone to explain briefly what hooks to what and kinda how it work. This is my first engine build by myself and also my first project car fyi.
 
If you are buying one from one of the companies that sell them, part of the ordering process is what transmission you are using I believe. Pretty sure Modern Muscle can answer all your questions with a phone call.
 
Depending on what company you use, they have ecu's and harnesses available in kit form. So, for example if you were to order the mega squirt kit, you would not need the factory ecu. You would not need a separate ignition box. As 1973B'cuda said, they need to know what trans you are using to give you the correct system. If you were to use the modern trans also, it is computer controlled. The kit you buy would then control the modern trans, too. Chris at Hotwire Auto is fantastic to deal with. I have used there product.
 
408 swinger said:
The kit you buy would then control the modern trans, too. Chris at Hotwire Auto is fantastic to deal with. I have used there product.
Click to expand...

So far as I know there is NO aftermarket engine computer that will control Chrysler transmissions. Only the OEM computer I think. So this leaves you with having an OEM one reflashed.

OP if you are using an "old school" 727 there is no computer connection to that. Likewise if you want an OD you can use the earlier hydraulic, not electronic A500/518 overdrive with the 3 wire connector to control the OD

There was a guy on here did a Megasquirt G3 hemi in a Duster. Wade Kuell??? Look it up..........Here:

 
67Dart, you are correct. I was referring to the hotwire kit. I should have also noted that the hotwire stuff uses OEM computer. Therefore if using hotwire, and they are aware of using modern transmission, they will set you up accordingly. I should have been a little more specific. Sorry for the confusion.
 
So the after market options like the mega squirt and is basically a new computer to hook up to the engine and that's all i need for controlling engine wise?
 
Elwood blues said:
So the after market options like the mega squirt and is basically a new computer to hook up to the engine and that's all i need for controlling engine wise?
Click to expand...
You will need their harness as well.
 
Ok so I need the aftermarket computer and harness, but why is it that I've read some people talking about using mad boxes with their after market computer? Do some of them not control spark or would their be a different reason
 
You can piggyback the MSD igniton over the fuelie harness to control spark. Reason for doing this, is being able to control the timing map, when using a factory computer. MS3 boxes have timing control features already .
 
If you want to get some questions answered about the megasquirt you can contact Mike at EFI Source. He was great at answering the questions I had about their products. I would up getting the gold box xtra so that I had one unit to controls the engine and 4L60E transmission I am using. Having one just makes for a cleaner install. I have yet to get it up and running so I cannot say how easy it will be to tune but it did come with an initial tune installed.
 
Before we put the cart in front of the horse, how about a little more info than I am putting an 05 5.7 Gen III in my car. Is this a junk yard motor ? If so ( probably is) did you buy the complete engine with all manifolds, serp belt setup, alternator, starter, a/c compressor/, p/s pump, hoses, factory intake setup with TB, injectors, harnesses and airbox ? In other words a complete engine assembly minus the trans ? These questions need to be answered way before you worry about the wiring for after market anything.
 
Yes this was a junkyard engine but i am in the process of the rebuild. I got the full package with everything. The only thing I didnt get was the computer.
 
Computers are cheap enough. Can reflash it cheap. What transmission?
 
If I am not mistaken, with a 727, you can just use a manual transmission flash.
 
Call Hotwire and talk to Chris he will answer all your questions. He will give you the straight answers and tell you what to expect. Just spoke to him last week about going to a manual transmission. He is very helpful. He helped me with all my self inflicted problems and he even contacted the manufacturer of my tach on how to hook it up for me.
 
You must log in or register to reply here.
-

Back
Top