HELP 1991 GMC Jimmy Lost electrical power to fuel pump

[RaTcheTmasTer]

So I have tracked down a couple of facts.
Pump ran when I used a motorcycle battery to connect to the frame in back and positive wire to the pump plug and the pump works.
But it doesn't work when I turn on the key. No pump sound and does not fire up.

The truck turns over and will start with starting fluid for a second.

I checked the Fuel pump relay and it is good.

But I know just noticed that the headlights don't work and the interior lights don't work either????
Anyone have a diagram for the 91 Jimmy Blazer full size square body?

An ideas or tips?
Someone said it could be the computer?

Thanks . Tim