77 280z I am only seeing 10 volts at the pump battery is full charged. Can anyone tell me if this is normal

No, it is not normal. I suggest looking for corrosion in the connectors in the fuel pump circuit. Don't forget to check the EFI relay and Ignition relay. The relays and the contacts associated with them could cause a voltage drop.

Thanks I already replace the Ignition relay. I will keep troubleshooting

I suggest you follow down the line to see where you're getting the voltage drop. You should be able to get a meter lead in the backside of the connectors.

It kind of suggests a stuck pump. More details about what you're trying to figure out might help.

If he’s getting less than 12 at the harness disconnected, I would guess it’s a problem up stream.

This indicates a significant voltage drop in the circuit, which is common in older vehicles.

Responding why I am asking. Car would not start during troubleshooting found if I applied 12 V to the fuel pump it would run so I checked the voltage during start procedure and found only 9.810 V. I’m now working my way back through every connection. Checking to see if I can find exactly where the voltage drop is occurring.

Looks like the AAR (air regulator) is on the same circuit. The full 77 wiring diagram is in the Resources area if you want to find the connectors. And, the ignition relay and EFI/pump relays can be taken apart. Sometimes there's a surprise inside. Might be worthwhile to measure your voltage with a small load, like a light bulb.

Edited July 3Jul 3 by Zed Head
surpise > surprise

My gut tells me he will find corrosion or a bad ground at the relay.

I found the drop happens at the relay's incoming voltage when cranking the engine. I have wired in a second relay for now as I keep investigating.

57 minutes ago, mrfixit.joe said:

I found the drop happens at the relay's incoming voltage when cranking the engine. I have wired in a second relay for now as I keep investigating.

Which relay, and which wire?

Keep in mind that the problem could still be upstream of where you found it. Corrosion at the splices is a real thing in a car that's about 50 years old.

Edited July 5Jul 5 by SteveJ