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Hello, I got my new system installed(Lennox 16ACX, ML296V) last month, and Nest wired as 2-stage cooling. What concerns me is I double it the system is wired as 2-stage cooling. I never had 2 stages of cooling before, but it feels like the 1st stage is pretty strong cooling and I don't feed the comfort improvement with 2 stages at all.
I checked the installation manual on both the furnace and ac unit and found 2 suspecting points.

1. The furnace manual says:

"The unit is set up at the factor for single stage cooling. For two stage cooling operation, clip the jumper wire located between the Y to Y2 terminals on the integrated ignition/blower control board"

So what does this "clip" mean here, does it mean to cut the jumper wire that is there for the default single stage? I opened the furnace door and found a jumper wire between Y and Y2 is there, no cut. I doubt the crew forget to do that and left my used as a single stage AC?

2. Next question is about the wire from the furnace to the outdoor unit, my old system had 18-2 cables, so only 2 wires in that cable, and my 16ACX manual shows there should be 3 wire to the outdoor unit, Y1, Y2 and C. However that 18-2 wire goes outside now connects to the Y1 and Y2, and there is no wire for the C connection. Seems like they should change out that cable to a 3 wire cable and they somehow cut corners to have a C wire from elsewhere in the outdoor unit?

I am going to reach out to the company that installed my system but I'd like to get some education from elsewhere first to better understand this.

Thanks in advance!

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