400E's got no squirt.

[CarolinaMBZ]

My 400E has a heated windshield washer reservoir with a pump that doesn't work. Fuse is OK and when stalk pushed in to activate, wiper does the standard 3 cycles. I cannot hear the washer motor when I do this so somehow it is not getting juice or is otherwise inoperative.

Questions: 1) Is the jet motor attached to the reservoir (in one of the external plastic tube like housings) or is it somewhere else?

2) Any tips to test (that hopefully won't involve 2 people as its just me and I can't reach wiper stalk and reservoir at same time (I do have multi tester).

3) Any known common failures for system that I could go to first before undertaking any involved disassembly/testing (it sure is tight in there with a V-8 instead of an inline 6)?

All help appreciated.