Does anyone recognize the part number D9AB 4489 PA. It is a red plug (Ford logo) with nothing plugged into it. It is located near the battery on my 1984 F150. I'm guessing that it is a tap to connect a diagnostic tool to pull codes from the computer but that is a WAG. Any help would be appreciated.

 

The diagnostic port is a red connector with 6(?) slots, and another single wire connector (color not known). It should be located near the starter solenoid. No clue what number would be stamped on it though.

 

Rogue Wulff: Thanks a lot. As we say down home "yup 'at's da one". I'm converting from feedback carb and TFI to std. carb and DS2 and trying to figure out what must stay and what can go. In the same wire group as the diagnostic port there is a wire to the ground battery post (with a disconnector). Any idea what that is? Ground for the computer maybe? And while I'm throwing out questions, how about the identity of a single wire in the same wire group as the MAP sensor wires, but it is a fusible linked wire that is connected to the battery side of the starter solenoid.

 

I can't really answer any of the specific questions about this system. I have a scantool laying here, but have never owned anything it fits......
My 95 is OBD-II (for now)....

 

It cannot be 4489, as the 4000 group is related to rear axle parts.

The 14000 group is related to wiring.

There are no Ford part numbers marked on parts after 1956, just casting or ID engineering numbers (when applicable).

 

Sorry for the misnomer! You are correct in that it is D9AB-1 and then on another line 4489-PA. I missed the 1 on the top line originally. Do you know if it is, in fact, the diagnostic port?

 

Looking up 14489 connectors: It's impossible, because all Ford shows in parts catalogs are the specs, and pictures of the little charmers, and there are dozens of different ones.

I was unable to cross over that D9AB-14489-PA engineering number to a part number. There are over 30 D9AB-14489's listed in the master cross reference catalog, but none have that PA suffix.

Sorry.

 

Whisler - post a picture of what you're talking about.....

 

Do you have a small electronic box with a lot of wires to it under the drivers seat? That would be the computer for the feedback carb.

On mine I disconnected the battery, went under the truck, cut the harness going to that box, and pulled all those wires out of the truck. The black with the disconnect is the computer ground and the other fusible link is computer power.

Also, on mine that harness was almost entirely seperate from the main truck harness and was easy to remove. Also got rid of those solenoids on the valve covers, egr, airpump, etc.

 

X2! Did the same on my '82. Amazing how well the Crafsman hose cutters work on wires. I cut through all of that bundle going under the seat in one chomp.

Actually, at least until '82, Ford did us a really big favor by running the computers on a totally standalone set of wires and sensors. There was a separate temp sensor, separate oil pressure sensor, etc. I removed those as well as all of the wiring associated with the computer and it cleaned things up dramatically.

 

Well being the impatient type, I started disassembling the wiring harness and figured that anything that led to the computer was not needed. I was almost right in that the choke heater wire was taped into that harness but was easily liberated. Since I marked it when I took it off the choke, I knew which one it was and being attached to the alternator that verified it.
I'm sure glad to hear I was right on the identity of the two wires in question because the only thing left of that whole wiring system is the computer itself. i can't get my head up under the dash far enough to figure out how to detach it or it would be gone too.
Next comes removing the TFI coil and installing all the DS2 wiring, coil and module. Then install the distributor and new carb and hope it runs.
Thanks to all the helpful people and info on this site, I'm pretty sure I've got it right.

 

Interesting....

My electric choke is powered through an oil pressure switch and is 12v.

And my computer is under the seat(yes, it is still there), not the dash. Also, the harness ran under the truck, not through the firewall. The computer harness was mainly on the passenger side of the engine compartment, then ran back to the firewall above the trans, and then down under along the framerail to the computer under the seat.

Did they move it in later years?

 

That's the way my 82 was set up - computer under the seat with wire running through the floor, along the frame, and up the back of the engine to the myriad of relays, sensors, etc. I took the computer out and sealed the hole with several layers of aluminum duct tape. Not the fabric stuff, but the true metal tape. That was 1 1/2 years ago and it still looks new and the adhesive is so strong it isn't gonna leave.

But, my electric choke runs right to the alternator and not through an oil pressure switch. The choke is hooked to the Stator terminal on the alternator, which only supplies about 7 volts and only then when the engine is running, so there's no need for the oil pressure switch.

 

They must have changed things between '82 and '84, because that whole wiring harness for the "myriad of relays, sensors, etc." (like the sound of that) went through the firewall to the passenger side of the steering column and the computer was up under the dash. I will have to get a solid grommet to fill the hole in the firewall where the harness went through.
The choke wire wasn't really part of that harness but they used one alternator tap to power the choke and something else in that harness. It was easy to liberate the choke wire, just unplug it from the harness wire.

 

Yes, Ford must have moved the EEC-IV computer in later years, because it was located under the dash on my 1985 model. There was a rectangular shaped black rubber plug on the firewall on the driver's side of the engine where the wires feed from the engine bay to the EEC-IV computer under the dash. There must have been about 60 wires stuffed in there on my truck. When I finally had it all out, I had about 50 feet of wires with some really ugly splices that I was glad to see gone. The Duraspark swap DRAMATICALLY cleaned up my engine bay.

The red rectangular shaped open plug is the EEC-IV diagnostic test port, so it can removed. The battery disconnect is for the engine computer so it can be removed, along with the yellow fusible link wire connected to the starter relay. All of the emissions will need to be removed, including the EGR solenoids, MAP sensor, O2 sensor, and the EVAP components, as they are all controlled by the EEC-IV computer. The EGR valve and EVAP components can be hooked back up using thermal vacuum switches and vacuum relays, if you wish. The TFI ignition module and distributor and all of its associated wiring needs to be removed, along with the coil. The oil pressure and coolant temperature sending unit wires are part of the computer wiring harness, so they have to be removed too. The stock Duraspark wiring harness will have the replacement wires for both sending units, tachometer, distributor, coil, and ignition module. At the back of the engine and along the plastic inner fender on the driver's side, you will see where the EEC-IV computer harness plugs into the truck's existing wire harness. You will unplug it here, and that is where the Duraspark wire harness will plug into. The Duraspark ignition module bolts down on a raised area on the inner fender.

The stock Ford electric choke is actually an electric-assist choke that was used in conjunction with the thermostatic hot air choke. The hot air choke is the primary choke, the electric-assist only works at temperatures above 60 degrees to help the choke come off sooner for emissions purposes. The electric assist choke doesn't work when it is colder than 60 degrees. This would be connected to the back of the alternator and it runs off of 7 volts. A fully electric aftermarket choke would not be connected to the back of the alternator as it would need 12 volts.

More information with pictures:
https://www.ford-trucks.com/forums/1...on-how-to.html
https://www.ford-trucks.com/forums/9...wontt-run.html