Yes they have two connectors, ones three pin and the other is two pin and held on with a clip.

Possibly, there is no harm is trying, it may have been you unplugging it that has separated the wires otherwise the fact it does not come on when it's unplugged indicates the sender (Assuming of course you do have the correct level of brake fluid!)

Reservoir is same as certain other models, so a visit to the local scrappy could pay dividends, if you have trouble let me know!

Martin