fuel pump output voltage

[STOICH]

When the MS2 first turns on, it runs the pump for a few seconds via the purple wire, then the pump shuts off- In a test, what voltage should be seen from the purple wire during the first few seconds before the pump shuts off- My pump was working, not its not. Manual test its working fine, but I have no signal from that purple wire? The lights still flicker on the MS like always when first powering up

[TZepeSH]

Fuel pump output provides a ground to the fuel pump relay. So you will see a ground when the pump is powered on and battery when it is powered off.

[STOICH]

That makes good sense. I'm suspicious I damaged that circuit- is there any test? I can run the pump directly. but I accidentally had the pump itself, MSD and the MS on the same 5 amp fuse as I am swapping the ECU and engine to a new car. The pump ran until it saw fuel pressure, then blew that fuse, and now the pump is no longer activated by the MS?