I'd support this line of reasoning if the OP hadn't mentioned that the bike "cut out" and hasn't run since. I'm assuming the battery hasn't been fiddled with in the interem.
Do you get the same voltage drop across the relay with the fuel pump disconnected? If so, then it is likely the relay. If not, could be crappy connections (or wiring) on the load side.
Have you confirmed that you're only seeing this voltage drop at the fuel pump? If so, DV4 is on the right track - but make sure other point load supplies are not also falling off before an indictment.
I have had 6 Gen1s - 3 acquired AFTER this one. It is the best VMax I have owned. I am the second owner. It was 100% original when I got it - that lasted about a week.
Illness forces sale.
It now sports (I hope I don't forget something:
Morley midcut seat
Morley single tube frame braces...
I sold a beautiful 05 last year here in Phoenix. Got $4500 for it - but it had covered 33k miles. Still pristine and ran like a VMAX.
I probably could've gotten more, but didn't want to draw out the process.
I believe the notion is that one replaces spent friction discs and at the same time the spring is upgraded. The stronger diaphragm helps prevent the issue in the future.
I installed Sean's recommended kit with the heavy duty spring and "half- disc" replacement. Nice, easy clutch pull. No slippage yet... I don't expect any.