u/Helpful_Pumpkin4477

My dash lights come on and the battery is brand new, but it won’t crank at all.

There’s a part in the engine bay that does very fast ticking when the ignition is on, and it sparks if it touches any other metal part of the engine. If it’s not touching metal, it won’t tick. I’m pretty sure it might be an aftermarket fuel lift pump? It has 2 fuel lines going to/from it and only 1 wire connected.
The van ran perfectly a year ago but has been parked up since.

Vehicle details:
Mercedes T1 208D (1989)
98k miles
Manual gearbox

Any advice would be massively appreciated. Has anyone had this before or know what I should check first?