I have a 1988 F-150 with the 5.0 and I'm having issues figuring out how to get it started. I had a problem starting the truck due to not enough power getting to the starter as it was barely turning over. The truck had also been running more rough than normal for a bit before it stopped starting. So I checked the alternator and battery. The battery was bad and alternator was good. I replaced the battery and the truck turned over stronger than it had since I have had it but it didn't start and I didn't hear the fuel pump come on. I checked for fuel at the rail and there was no pressure so I started diagnosing the fuel system. I'll try to explain what diagnostic tests I've done, what the results have been and what else I've done.
First I followed this diagnostic guide:
http://easyautodiagnostics.com/ford/...-relay-tests-3

The first two tests I got normal results. The third test I got the rear tank pump and the inline pump to run but not the front tank pump which is what I had been using. In order to test just the tank pumps I disconnected the fuel line before the inline pump. I also replaced the fuel filter at this time since it was dirty but still had fuel passing through it.

On the fourth test I got strange results. I got between 6-8 volts constantly during this test even without the key in the ignition.

I then followed a guide for testing the eec relay which it passed.

Since then I have replaced the eec with a junkyard swap and the fuel pump relay (new)

Now on test 4 for the fuel pump relay I get almost 12v constantly without a key in the ignition.

It still doesn't even sputter or try to start though there is a lot more pressure at the fuel rail. I plan on testing the fuel pressure tomorrow. I already rented a fuel pressure tester from O'Reilly's and it didn't register anything even though when I manually hit the schrader valve it seems to have lots of pressure. So I am going to try my luck with another tester tomorrow. I also plan on going through a guide on diagnosing other electronic components such as the pip sensor that could be causing issues. This is the guide I'll be using:

http://easyautodiagnostics.com/ford/...module-tests-1

Anyone have any advice on what else to look at or any other useful suggestions? In case you're wondering, no I haven't checked for spark yet but will obviously be going over that tomorrow and if I still haven't figured it out I will post again with my results from those tests. Any help or advice would be greatly appreciated.