my 98 F150 isnt getting spark or fuel it ran got new truck and started it every week or so and then one day it just wouldnt start. checked relays and fues in the power dist box and under the das some under the dash arent working but alot are any ideas no cel at any time scanner wont read it and it does have 2000 model 4.6
Check specifically, the cigarette lighter fuse. If that is good ( test it ), check for 12v at the lighter socket. If this circuit is dead, the DTC link to the PCM won't happen. If you have PATS, is the red light on the top of the dash blinking when the truck is just sitting ?
Check the battery output. Should be 13v or greater. You need 10v just to run the PCM, and 13v to run the ignition. If the voltage is good, check the ground cable to the engine from the battery, then the ground strap from the engine to the firewall.
If the PCM was swapped when the engine was changed, there could be an issue with the key. You may end up having to have the pcm/keys flashed to the exact combination you have.
I have a 98 f150 4.6 it has no spark or fuel and no check engine light. I e checked the relays and fuses in the power distribution box and all are working but some of the ones under the dashboard are not working and some of them are but all fuses are good
Which ones under then dash are not working and how did you conclude this?
They all must work.
For instance under the dash is fuse 19 for the PCM.
In the engine bay is #19 and 24 for fuel pump and PCM.
Is there any power indication to the PCM?
The fuse and relay assignments are in the op manual for 98 on pages 134 to 141.
Does the fuel pump run?
Are any fuses open by testing other than just looking at them?
Have rodents chewed the wiring at some point?
You have to find something to go on.