Okay, so I have an 89 F150 4.9L EFI system that I finished doing a frame off resto pretty much (cab swap, all new body panels, new bed, etc.) However the drive train and motor were not touched at all. OF course, some electronics were unplugged and rerouted into the new cab, but I'm using the same PCM, ECM, steering column, etc. and they're all plugged in and all are grounded. I can honk the horn, use my turn signals, and even shift the 4x4 stick back and forth and the dash light for it comes on. All the electronics work but when I go to put the clutch in and turn the key nothing happens... I hear no hum of the fuel pump on the rail or nothing. I can turn the key to RUN and jump the relay on p/s fender to where it tries to start and then spray starting fluid in the intake and it'll catch and run for a second until the vapors evap and it'll die. Does anyone have a good idea on where I should start? I can say I dont have the cab to frame ground clip on the p/s connected... but other than that I dont know what to think; maybe a blown fuse? Thanks for any input!

 

I have read I should check the fusable links going to/from the starter relay and something about the ignition wiring... I've looked online and turned through the pages of manuals (Chilton/Haynes) but no luck for a decent wiring diagram. Anyone have any inside on this? The help is much appreciated if so!!!

 

Here's two schematics for a 88. The 89 fusible links are a little different but the ignition switch wiring and clutch safety switch are wired the same.

The positive battery terminal is connected to the starter solenoid. On this same stud are connected a bunch of fusible links. The ignition switch mounted on the middle of the steering column gets 12 volts to the BATT terminals of the ignition switch as shown in the diagram. On a 88 the wires going to the BATT are two Yellow wires.

When you turn the ignition switch to start, the 12 volts from the BATT terminals passes through the ignition switch (pin M in the diagram) to a Red/Light Blue wire to the clutch safety switch. If the clutch safety switch is closed, the 12 volt passes through the switch (pin N in the diagram) and to the Red/Light Blue wire on the starter solenoid.

The solenoid energizes and 12 volts passes through the solenoid to the starter motor.

Note the ground for the control side of the starter solenoid is the passenger side fender that it bolts to. On my 88 there is a braided strap one end is attached to one of the studs that bolts the upper intake to the lower intake runner. The other end of the braided strap bolts to the hood near the passenger side hinge. I believe this is the body ground to the engine.

An indication the EEC is getting power is when you turn the ignition On the Check Engine indicator should be on. The Check Engine indicator is to the right side of the left turn signal indicator. If the Check Engine indicator does not light, you need to verify there is 12 volts to the EEC. The two small ground wires for the EEC are connected to the negative battery terminal at the battery negative post.

The Starter circuit is very simple, so get that circuit working first.

Schematic of the ignition switch.



Schematic of the clutch safety switch.

 

Thank you! I ended up figuring out my problem, the fuel pump relay was bad, not causing it to energize. So I got that, and then was able to actually start the truck by jumping the starter relay. I then traced it back to the clutch interlock switch, I have a lot of play in my clutch pedal and it wouldn't close the switch. So until I fix that, I bypassed the switch and sure be it she works like a champ! Many thanks for your help!!! I never woulda known where to look... I'm planning on going to the JY and pulling the switch from and automatic b/c I've been told that it's like a factory way of bypassing