Motorsport EFI harness problem: kinda long

1966ponyguy

New Member
Sep 3, 2004
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Kentucky
Ok, I am so close after 2 1/2 years of work. Ready to fire it up, but no go. I am using a Ford Motorsport harness which I have checked the connections about 30times now. I did find some great help on www.ford-trucks.com/article/article.php?id=107&action=print . I have checked the following: There is 12 volts at the TFI connector #2 and #3 in run, there is also 12 volts at the TFI connector #3 and #4 in Start. There is 12 volts on the red/green wire at the coil. There is 12 volts at the TAB solenoids in run. I also have 12 volts on the gray wire on both O2 sensors. I cannot get the fuel pump to come on. I have wired it straight to the battery to make sure the pump is good (MSD pump) and it works. Under the hood, I can't tell which of the two solenoids are fuel pump and which one is the AC WOT disconnect. I cannot find a 12 volt source at either solenoid on any wire. I think this should be an always hot wire for the fuel pump. The question I have is after going through the diagram about 30 times the green connector (#39) buy the ECM wiring does not seem to match any diagram or instructions. The Motorsport manual list the following wire colors, connections:

White/Red: Not used
Gray/ Yellow: 12 volts at run (tested OK)
Purple Wire: AC ON
Dark Green: Inertia switch then to fuel pump (2 wires connected together, no power anytime)
Pink/Orange: Speed Sensor - (not connected now, don't know if I will use VSS)
Green/ Black: Speed Sensor + (same as above)
Pink/Green: Check Engine Light and the Ign side of key switch

Wires I do have on the harness:
White:Pink: Taped off
Gray / Yellow: Connected to 12 volts Ign switch
Purple: AC On
Dark Green: (Both connected to fuel pump wire going to inertia switch
Pink: Not connected (VSS connection)
Gray / Purple: Not connected (VSS connection)
Pink/Green: Check Engine Light then to Ign side of key switch

Ford Trucks.com suggests to unhook the tan wire from the ECM to the relay and attach and ground the wire. This should turn on the Fuel pump. WHAT TAN WIRE?

Anyone used a Motorsport harness and had this problem? What are the correct part numbers for the ECM, Fuel, and AC WOT relays?

How can I tell that the ECM is even receiving power during key on and start?

I really want to hear this run.
 
Ford Trucks.com suggests to unhook the tan wire from the ECM to the relay and attach and ground the wire. This should turn on the Fuel pump. WHAT TAN WIRE?

On the 88-91 harnesses the wire they are talking about is wire #22. The diagram I have shows a Tan/Light Green wire. However, you are using the Motorsport harness which I believe is setup like the 91-93 harness for the pinouts. In this diagram, wire #22 goes to the same spot but it is a different color. For the 91-93 harness, wire #22 is Light Blue with an Orange stripe. On the diagram, it shows this wire spliced into the "Data Link Connector". Unfortunately this diagram doesn't show the pin-outs on that connector but I think you can figure out which one it is by the color. Look for a Light Blue wire with an Orange stripe connected to your fuel pump relay and your "self test plug"/"Data Link Connector".