Engine will not turn over?

Are you sure about that? You have a 12 volt system so that is something that you need to get to the bottom of. Check it again and if you really only have 6 volts, then unplug all of the injectors and measure it again. If it comes up to 12v now, leave the meter attached and start plugging in injectors one at a time. If the voltage suddenly drops again, that injector is shorted out.

Check voltage at starter batt treminal should be same as batt. Next check voltage at solenoid terminal while key is turned to start. If both good then replace starter

Check the voltage on both sides at INJECTOR fuse #7, 10amp in the dash fuse box.

I think your in the wrong box
It's right here

The injector power goes directly from there to the injectors so you need to find the connector or whatever is causing you to lose that power between that fuse and the injector.

Do you hear the fuel pump come On when you turn key on? If not check fuel pump fuse and fuel pump relay if so, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light.

No, it just means you just wasted a bunch of time because you didn't know how to measure it. That line back to the computer is nothing but an open circuit to the quad drivers and your real lucky you didn't jump them together or you could have taken out the computer. Your back to square one which is where we should have started.

Here is the procedure. Do every single test.

All "crank, no start" conditions are approached in the same way. Every engine requires certain functions to be able to run. Some of these functions rely on specific components to work and some components are part of more than one function so it is important to see the whole picture to be able to conclude anything about what may have failed. Also, these functions can ONLY be tested during the failure. Any other time and they will simply test good because the problem isn't present at the moment.
If you approach this in any other way, you are merely guessing and that only serves to replace unnecessary parts and wastes money.

Every engine requires spark, fuel and compression to run. That's what we have to look for.

These are the basics that need to be tested and will give us the info required to isolate a cause.

1) Test for spark at the plug end of the wire using a spark tester. If none found, check for power supply on the + terminal of the coil with the key on.

2) Test for injector pulse using a small bulb called a noid light. If none found, check for power supply at one side of the injector with the key on.

3) Use a fuel pressure gauge to test for correct fuel pressure, also noticing if the pressure holds when key is shut off.

4) If all of these things check good, then you would need to do a complete compression test.

In tank fuel pumps are cooled and lubricated by the fuel in the tank. When you run a car

out of gas or very low, it pumps a lot of air through the pump which overheats it and causes

some severe wear and many times, failure when they cool off.
You will need to use a fuel pressure gauge to verify this

Can you please reword that! Hneed vehicle model, make etc.

Hi:
What happens when you turn the key? Do you hear a click?

Joe