Not sure where position "U" is I have a Owners manual,Haynes, & Chiltons manual.....And I just replaced the Ignition switch.

 

My information is from Ford on line repair, but it does not show a diagram of the fuse panel. All it shows is a 20A fuse in the underhood fuse panel that controls voltage to the coil. I will keep looking to see if I can find anything.

 

Great..... I was also told from the local Napa parts store i could run a wire from Batt pos+ to the pos side of coil pack and if it fires up when i turn the key then i either have a break in the pos wire or a bad relay...I'm kinda grasping at straws now 3 weeks is a long time without my truck...

 

Well i did the hotwire thing...still nothing except the relays all clicked but still no fire to the plugs.... Question: is there something that tells the injectors when to open. I've checked the pressure relief valve on the fuel rail that feeds the injectors and I have great fuel pressure.

 

I understand that you dismissed my question about the alternator/voltage regulator. The only reason I suggested testing it is because ford is closely related to mazda, they have been working together since the 70's, and every time I have seen a voltage regulator on a mazda go bad the vehicle would not start. your voltage regulator is internal on the alternator. If you haven't gotten it started it wouldn't hurt to have the alternator tested. It's easy to remove and free to test at your local auto parts store. If your alternator is good then I would recommend that you have your ecm tested to see if your "computer" is bad. Your ecm is most likely located behind the dash on the passenger side behind the glove box. Good luck with your repair. P.S.- make sure the battery is disconnected before your remove the ecm if you need to. Sorry to chime in. I was just trying to help.

 

I wasnt ignoring you..sorry. I've had the ECM tested on my model truck it is located on the fenderwell driverside and it tested good. the coil tested bad and I replaced it I ran a hotwire from the pos Batt post to the pos coil conector and all the relays clicked,fuel pump primed up. but when i turned the key she cranked but no fire at the plugs.

 

bronco is correct on the ECM. It is located on the left side of the firewall. It should be located under the dash close to the brake pedal assembly.The part on the fenderwell is the Thick Film Integrated (TIF)module (ignition module). If you ran power to the coil, and still no spark, thet should rule out the fuse. Wish I had it where I could look at it. It is really hard to diagnose these over the net. Still thinking.

 

Morning guys, Well I checked with the Napa guy and found the exact location of computer and since there is no way to test it, it has to come out but I'm going to need help with that. When I try to pull it out the bottom corner hits up against the splash guard inside the engine compartment which means I have to take the hood off and then the fender to drop that down to get it away from the computer to get it out. So it's gonna be awhile. And then I'm not sure if the computer is the real problem. Computer costs are from $130-$360 depending on which one I need. I'm told i have to get the exact coded computer for my truck. So until i can get it out to find the code number I'm dead in the water for now. Thx

 

There is no ballast resistor; they went away with EFI.

The ignition switch does NOT feed power to the ignition coil (directly); the computer "fires" the coil by feeding power to it'sd primary at the proper time.

If you have not checked, crank the engine, with a plug wire removed, see if there is spark to that plug- a plastic-handled screwdriver used to make contact inside the rubber boot, holding shank near, 1/4", to a grounded surface while cranking. If spark to plug exists, looks like a FUEL issue:

Have you checked for fuel pressure at the Schrader Valve test point? Just because a fuel pump is heard running, does not mean proper pressure is available to the injectors. BEST is check pressure w/ fuel pressure gauge. If low, possible filter problem. imp

 

If I may,
here is something you can try-- depending on just which system you have on the engine. If it has a distributor --transition year-- the pick up coil in the dist is what sends the signal to the coil to fire the plugs. With a test lite check if you have voltage to the coil when the key is in the on position. If so , the next thing to try is to place the test lite on the other coil primary terminal (with everything connected) and crank the engine. The test lite should flicker indicating that the coil is getting the signal to fire. That would eliminate the pick-up coil as a possibility. But as I believe you stated in a previous post the light didn't flicker so I would check out the pick up coil and make sure it has a good ground connection in the dist.
If it does not have a distributor then the PCM gets the signal from a crank sensor and tells the coil to fire.
Let us know what you find and we can go from there. There may be an Ignition control module involved , but need to know what system you have first.