No Power on OBD connector

I have an 97 Ford F-150 with 150,000 miles on 4.6L engine. Last week it started missing at 45+ mph. The computer I purchesed did not work when I plugged it into the connector, but worked fine on my other car. The maker of the computer says I do not have an power on the connector and they were right. I checked all known fuses. The only fuse found blown was a power point. Replacing did nothing to help with the problems. Today I replaced the fuel filter, oxygen sensor, a vaccum hose that runs to a solenoid by the master cylinder, and PVC value. The truck seems to have more power, but still has the miss. The plugs are about 5 months old and the couple I looked at look fine. The check engine light blinks then goes solid. Since shotgunning is not working, were is connector getting it's power from or is something like the PCM gone?