Master cylinder switch, Lost my red dash light Options

[EJP914]

Just got a new master cylinder from PMB for my '73 1.7 and noticed the switch on the side of it has only 1 spade wire connector. My old leaky MC (original) has a 2 wire switch with a brown wire and a brown/white wire. Not knowing what I would do with the extra wire on the new single connector switch, I put the old 2 pole switch in the new MC. Now the big blinking red light on the dash gauge that tells you when the e brake is on no longer works.

Is the old 2 pole switch not meant to work in the new MC since it came with a single pole switch?

If I put the single pole switch back in in the MC will the brakes need to bled again since I opened up the brake system?

If I put the single pole switch back in, guessing the brown/white wire goes to the switch and solid brown wire (ground?) I can ground to some bolt near the MC?

I checked the brown/white wire with a test light while the ignition was on, and it did not light up. Should this wire have power with the key on?

Maybe the non functioning dash light is a wire problem and not the MC switch???

Looking for some help. Would appreciate the guidance. Thanks.

Ed