Wiring for Novice

[zehnder]

Neat site here! I`ve installed a 92 Q motor & trans. into a Dodge Dakota using the Q`s ex. manifolds (reworked),fuel pump&controller, radiator, brake booster and m.cylinder(for clearance),and steering pump. Everything fit between the rails with some custom mounts for engine and trans, and hood ribbing removed. Before I did all this, I contacted a local ignition shop to see about getting the Q`s ECU and wiring harness married up with most of the mopar chassis wiring. The shop owner said he has done similar custom wiring and I used him before for an older Vette wiring upgrade. Well, He is having problems and maybe losing interest. I`ll have to light a fire under him or pull it and try it myself. My sophmoric question is, since I have the Q`s ECU, Trans.,Fuel pump,what minimum wiring connections do I need to fire this engine? Plus, what about a Tach. or engine check? I`ve checked this whole site but there isn`t details.PHM!

[elwesso]

I woudl highly recommend that you get a trans harness.

I think the first step is getting the engine running then you can get the trans going.

I guess you're probably oging to have to put an aftermarket tach on, doubt that concerns you though.

I think pretty much if you give the ECU power and everything is hooked up to the factory harness, it should run.

[zehnder]

Yes, I will need to plug in the trans, eventually. The harness from the Q was tied into a pack of wires under the drivers seat, I didn`t unwind this harness consisting of 20 or 30 wires. I presume that I can make a small harness up but where will these wires run? Straight to the ECU? I read somewhere that the TCU(transmission control unit) is inside the trans. itself. Is this true? Plus, the fuel pump, controller wires in the Q entered a harness behind the back seat that was another pack of wires. I saved the pump controller but got a new pump. Now these wires(pump and controller) run where? ECU? I was figuring on making up a simple harness with a fuse. Looking at a FSM wire schematic makes my eyes roll back in my head, which is why I wanted it done by a pro in the first place. I was hoping someone had made up a bear bones wiring diagram for an Ignition and Fuel system set up sans Q45 megawires!

[elwesso]

The trans computer is located on the drivers side kick panel of the Q, same place the ECU is located just on the other side.

I assume you have the complete wiring harness for the motor, right?

[zehnder]

I have the engine harness that enters the firewall and connects up with the Q`s ECU. Concerning the Trans computer, Lucky for me, the guy who has been working on it pulled it, because as of now, the donor car has been pieced out. Ha, someone had told me trans and computer are a unit! Back to engine start-up, FUEL, I guess ignition key sends power to a fuse link,then to the pump and pump controller, then wires from the controller go where, ECU?..... SPARK, When you say, "powering up ECU",I assume this means 12 volts will come from the ignition switch circuit also, then to the ECU, right?..... AIR, Got that!.....Is there any ANTI THEFT issues involved? I was gazing at the schematic and I saw that it made reference to pins at the ECU As you may tell, my auto wiring skills are limited to pre-eighties , and luxury car wiring is particularly mind numbing. This may be boring you a lot but I`m trying to grasp this so I can, at least, follow along as I talk to the dude who is working on it.

[RichZilla]

Not that I have looked at the FSM yet, but most Nissan computers have a fuel pump relay output pin. Often using an earth signal to turn it on. Why can't your auto elec use the FSM?

[zehnder]

He can, its just that the guy has a lot of business all the time and keeps pushing off my project. I was probably to easy going and he figured he would use me as a fill in job when he was slow. Not any more, I gave him a time frame and will pull it out of his shop if he doesn`t meet it. If I pull it, I wan`t to educate myself to either attempt the wiring myself or to get another auto electrician up to speed. It`s a ***** to come in on a job that is in progress.

[RichZilla]

It`s a ***** to come in on a job that is in progress.

That is very true. When people try to wire their cars up themselves and bring it to the shop for us to fix, they end up spending far more money than if they'd just brought it to us in the first place.