I have pulled the motor out of my 1984 f150 I6 and have started a rebuild. When the motor goes back in I am converting it to a non feed back carb and dura spark 2 dizzy. When I pulled the motor I unpluged all the sensors and from the thick harness. I was wondering if I could completely remove the computer box and that old harness due to the fact that none of the sensors are going to be on the new motor save for ( oil, water and rpm) that are in the new harness for the dura spark 2. This truck has Ac and it works great does the ac need the computer to work I noticed that the "condenser" has a plug from the thick harness going to it. Also will the truck start without the Thick harness ....Any info will be of great help, and thanks in advance!

 

Your truck was wired for both a computer and Duraspark-II.

The A/C is not computer controlled on this model.

The duraspark-II harness will plug into the main Underdash harness. You should be able to just unplug the TFI-IV engine harness, and swap them out.

With A/C you are going to need a few more parts to do this conversion.

You will need the A/C harness extention out of a donor truck, or to make one yourself.

Also some models including the 300-6 had a Carburetor Throttle Solenoid to open the throttle plates more to compensate when the A/C clutch is activated on the compressor. This is so you won't see a increase or drop in RPM when you turn on the A/C. You will need the solenoid and bracket to hook to your new carb. Both of these parts are obsolete, so you may be able to do without it untill you find one in the wreckers. Vans, Trucks and cars use something simular, or someone here may have one.

The Basic wire colors from the A/C clutch on the compressor to the evaporator thermostat is Black/Yellow hash.

The Wire colors from the evaporator thermostat to the A/C mode switch in the dash is Light Green/Purple Hash. The Carb throttle solenoid is inline with this wire between the two other components.

 

So ... I'm a little confused. Will I need to straight wire the connection coming out of the clutch to the controls in the truck?

 

The AC will still work after you remove the computer. I have had it load down the engine enough to make it die at a stop light. Mostly I just use the AC when I am going down the road. You can also just increase the idle speed during the hot summer month if it is a problem.

 

I removed my computer and all of the computer wiring harness.
Jim

 

Yes, you can straight wire it as you say, or get the little harness out of a donor vehicle.

There is only two colored wires.

The wire colors from the A/C clutch on the compressor to the evaporator thermostat is Black/Yellow hash.

The Wire colors from the evaporator thermostat to the A/C mode switch in the dash is Light Green/Purple Hash.



The Carb throttle solenoid is wired inline with the Light Green/Purple Hash wire between the evaporator thermostat and the A/C mode switch.

 

On my '82 the EEC IV computer system had it's own wiring harness and associated sensors, including oil pressure and water temp. I was able to remove all wiring that went with the computer awa sensors, making for a much more simple and straightforward system. I'm not sure your '84 is the same, but I believe it is.

 

The only difference with the 1980-1983 and the 1984-1986 is that he has an extra wire going to the computer, to control the idle when the A/C is engaged. This is so when the A/C clutch on the compressor engages the idle doesn't drop keeping a consistant idle.

This is done differently with 1980-1983 systems. There is a seperate little solenoid that has to be wired in to do this function.

As Jimsrebel states here: "I have had it load down the engine enough to make it die at a stop light. Mostly I just use the AC when I am going down the road. You can also just increase the idle speed during the hot summer month if it is a problem."

What I describing will eliminate that problem. It should be a simple as getting a short piece of wire, and the solenoid and bracket to fix that. Five minute job at most really. However, the parts are obsolete so finding the parts are possibly going to be hard to do.

 

Thanks for all the INFO guys! I will be diving back into it tomorrow morning removing the computer and old harness. I will post pics of the finished motor and keep you guys posted !