Fuel pump wiring? EEC is fried

[McM81]

Hey, I just swapped out my old 87 2.9l for an 88 2.9l the EEC and engine harness followed it and went well. I know about the changes for the 88 and conformed to that .my problem is the wiring for the fuel pump for the life off me I cant' make out heads or tales how the pump gets hooked up and which colors the wires that I am suppose to use I have power leaving the inertia switch which then leads to the big engine harness, from there I'm lost I know the 88 harness has a few more extra wires because of the options and ect. so when its going thru the main harness it comes out on driver side. the b2 I have is an 87. all I need is for someone to give me the colors and from where the originate from and how they hook out to the pump I know that when I turn the on key engine off there should be some relay clicking and the F\P should come on and shut off till I crank it the way its hooked up know the pump stays on r could be the EEC I guess but I still don't have that pump wired like it should be I can't remember for the life of me I was hoping that someone with electrical brains could help me I am at a lose and standstill please add you advice or comments.

 

[JerryC]

My advice is that you get on eBay and look for the ford electrical manual for both 87 and 88 BII's. They typically go for around $30.

 

[RonD]

Fuel pump(s) power

Battery(+)---(fusible link/fuse)-------Fuel pump relay-------------inertia switch------------Fuel pump(s)------ground

Fusible link will be attached to fender mounted Starter Relay(solenoid) post with Battery Positive cable

FP Relay(Green base) operation
Fuel pump relay's COIL gets 12volt when key is on, Red wire, this comes from EEC Relay(Brown base), EEC Relay also powers EEC(computer), Fuel injectors and spark.

Computer GROUNDS the COIL of the FP Relay to activate it which sends power to the inertia switch and then to the fuel pump(s)
Computer also Monitors voltage on the wire between FP Relay and inertia switch, this Monitor circuit will show 5 to 8 volts at inertia switch if key is on, FP Relay OFF, 0 amps so fuel pump is not getting power, just monitor voltage.

When you turn on the key, and each time you turn on the key, the computer will Boot Up and GROUND the FP Relay for 2 seconds, but only 2 seconds, you should see full 12volts at inertia switch at that time and then it will drop to the 5-8volt monitor voltage after 2 seconds.

Wiring colors for the FP Relay changed quite a bit, Red from EEC Relay was the only constant.

There is a test/bypass for the FP Relay's Computer Ground
On the main engine harness running to the computer will be the ViP/OBD1 connector
Diagram seen here: http://www.therangerstation.com/tech_library/OBD_I.shtml

Fuel Pump Slot is IDed in drawing
If you put a Jumper wire from that slot to a Ground(battery -) then when you turn on the key the FP Relay will close and stay closed until key is turned off.
This doesn't hurt anything, you are just doing what the computer does

If you want to ID wires pull out the FP Relay from its Green Base
Key OFF
Test each slot in the base for 12volts, there should be only 1 slot that has 12volts, thats from the Fusible link(fuse) that comes from Battery, it has 12v all the time

Key ON
There should now be another slot with 12v, the Red wire slot, thats from EEC Relay

If you have the Ground Jumper in place on the ViP connector use meter to test for GROUND, slot with ground goes to computer
The wire color at the ViP connector for this Ground should be same color at the FP Relay base, "usually", but not always

That only leaves inertia switch wire, so you now have the 4 wires IDed

2.9l electrical diagram here: http://www.therangerstation.com/tec...es/Diagrams_ElectronciEngControls2_9_1of3.JPG

It shows wire colors but..............grain of salt, Ford changed the colors often

 

[McM81]

Thanks

Thanks Ron

 

[adsm08]

Ford never changed the color of the wire that feeds power to the fuel pump. It is pink and black. The plug is different between 87 and 88 though.

Its a 2 wire into 1 plug.