150 electrical problems
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New User
Joined: Mar 2003
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150 electrical problems
Hi,
1988 F150 5.0 liter EFI
No power at the coil
No Fuel pump activity
Will turn over from Starter Relay
Will not turn over from Key
When key is in "run" position, no accessories
When hotwired from + battery to +side of coil, asseccories came on...no start though from key
Have replaced
Ignition switch
EEC relay
Fuel pump relay
Have power to ignition switch (two yellow wires)
Have power to/through clutch safety switch
Have power to/through Fuel inertia switch
Is there a ground under the car, connected to the fuel circuit that may be making this happen?
Can I run 12V directly to the fuel pump (single tank system) and test the fuel pump??
HELP PLEASE
Thanx
Rich
1988 F150 5.0 liter EFI
No power at the coil
No Fuel pump activity
Will turn over from Starter Relay
Will not turn over from Key
When key is in "run" position, no accessories
When hotwired from + battery to +side of coil, asseccories came on...no start though from key
Have replaced
Ignition switch
EEC relay
Fuel pump relay
Have power to ignition switch (two yellow wires)
Have power to/through clutch safety switch
Have power to/through Fuel inertia switch
Is there a ground under the car, connected to the fuel circuit that may be making this happen?
Can I run 12V directly to the fuel pump (single tank system) and test the fuel pump??
HELP PLEASE
Thanx
Rich
Posting Guru
Joined: Jun 1999
Posts: 2,415
Likes: 3
From: Comox Valley, Canada
150 electrical problems
Does the truck have an ignition switch, with an actuator rod connecting it to the igntion key actuated switch/lock tumbler?
I have a friend who's igntion switch actuator rod broke. So no matter how much he turned the key the rod didnt actuate the igntion switch.
I say this because it sure sounds like the ignition switch isnt working.
I have a friend who's igntion switch actuator rod broke. So no matter how much he turned the key the rod didnt actuate the igntion switch.
I say this because it sure sounds like the ignition switch isnt working.
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
150 electrical problems
r_towle
You can put 12V to the fuel pumps, but make sure you get the right terminals on the gas tanks.
I think your lock cylinder isn't pushing the rod to the ignition switch.
ehret
The EEC relay on '84-91 is in the engine compartment, usually near the L hood hinge. In '92-up, it's in the engine compartment fuse box.
Dennis
The FP relay is activated by a ground signal from the EEC, but that relay switches the 12V side of the pump circuit. The pump's ground is a screw in the frame near the tanks.
You can put 12V to the fuel pumps, but make sure you get the right terminals on the gas tanks.
I think your lock cylinder isn't pushing the rod to the ignition switch.
ehret
The EEC relay on '84-91 is in the engine compartment, usually near the L hood hinge. In '92-up, it's in the engine compartment fuse box.
Dennis
The FP relay is activated by a ground signal from the EEC, but that relay switches the 12V side of the pump circuit. The pump's ground is a screw in the frame near the tanks.
New User
Joined: Jan 2003
Posts: 19
Likes: 0
From: Chesapeake
150 electrical problems
Thanks Steve,
I am going through my own ignition nightmare on my 87 F-150. As soon as it stops raining today I am putting a new EEC-IV module. It is the last component. I have already replaced the battery, starter relay, ignition switch, coil, TFI ignition module, distributer, rotor, cap, wires, plugs, I also bought an MSD box but I am going to wait till I get the timing close to install it. I used the chilton manual and it kept sending me in circles and having me replace parts and here I am about $350 in the hole on ignition and just keeping my fingers crossed on the computer. I had no power out from my coil with the old computer, I replaced it with a junk yard version that was close (302 from a t-bird) and had spark, but could not keep it running long enough to set the time. Hopefully the new computer (which was only $89) works.
I am going through my own ignition nightmare on my 87 F-150. As soon as it stops raining today I am putting a new EEC-IV module. It is the last component. I have already replaced the battery, starter relay, ignition switch, coil, TFI ignition module, distributer, rotor, cap, wires, plugs, I also bought an MSD box but I am going to wait till I get the timing close to install it. I used the chilton manual and it kept sending me in circles and having me replace parts and here I am about $350 in the hole on ignition and just keeping my fingers crossed on the computer. I had no power out from my coil with the old computer, I replaced it with a junk yard version that was close (302 from a t-bird) and had spark, but could not keep it running long enough to set the time. Hopefully the new computer (which was only $89) works.
Post Fiend
Joined: Nov 2002
Posts: 9,987
Likes: 7
From: Memphis, TN
150 electrical problems
The computer has nothing to do with the spark, other than advancing the timing ONLY IF the SPOUT connector is installed. If you're not getting a spark, diagnose the ignition system ONLY - the EEC isn't the problem. The Haynes manual has a great ignition diagnostic section.
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