The air pressure switch in my furnace has 3 connections, and I need to replace it with an upgraded part which has only 2 connections. 2 of the wires have the same color,Rose, while the third wire is red. Any help how to connect?

On the old switch were two of the wires going to the same terminal? I don't know that I've ever seen a pressure switch with 3 terminals.

They make a universal switch that has 3 connecter's. Can you post a model number of your furnace?

Thank you guys. The furnace model # is 035-17715-001 Rev D (1102) / 035-17715-001 Rev E (0503). The part number, original, of the pressure switch is 024-27576-000.

Bitters: The 3 terminal switch you mention, are the terminals Common, n/o, & n/c?

Grady, Yes they are. Had to install one last week. No time to order exact replacment.

I don't get any info with that model number. Is this a Colman furnace?

It's made by Unitary Products Group (York) so it could be a York or Coleman. Switch, Pressure 024-27576-000

http://postrv.com/HVAC/Gas%20Furnace...E%20(0503).pdf