M800 5v to fuel pump

[Turbo Johansen]

Hello, i have 16.7V at my fuel pump connector. But when i plug the pump in it drops to 5V. What can cause this?

 

[spoon]

Is pump running when you plug in? Bad/seized pump could cause higher load and voltage drop. Poor ground can also cause the drop on loaded circuit. Put a test light on connector and see if voltage stays good.

 

[Turbo Johansen]

New pump, stator, voltage regulator and main harness, still same problem.
When sled is ideling with battery running the pump the voltage on the connector is 16.7v and when i connect the pump the voltage drops to 5v

 

[kidwoo]

Where are you testing voltage when the pump is plugged in?

You sure you've got a good read?

 

[Turbo Johansen]

Directly from wires, i have testleads that jo can press trough the isolation.