I am trying to hookup a Honeywell programmable RTH6300B and I took jumper out of the R and Rc and hooked the red to R and the old C to the Rc. Now I can not get anything to work. I do not even get a read from my pocket tester from red.

Did I really screw something up? How do I fix it if I shorted the wiring?

You either blew the low voltage transformer or the fuse in the low voltage line. You will either have to replace the fuse or the transformer. Rc is used for 24v. Hot for cooling applications with a seporate transformer. If you didn't understand the wiring diagram then you should have left it to a professional to hook it up. It would be nice to know what you are wiring, furnace, heat pump a/c,etc.

Yes, you blew a fuse or transformer.

So if I blew the transformer what do I do? I see where the wires are hooked up to the furnace. Is the transformer there? All I have coming out of my wall is a wire. This is to hook up a furnace/blower/and ac

So if I blew the transformer what do I do? I see where the wires are hooked up to the furnace. Is the transformer there? All I have coming out of my wall is a wire. This is to hook up a furnace/blower/and ac Yes, the transformer or fuse should be inside the furnace. Look for a cube shaped object that is power by 110V and possibly one of the first things receiving power from your 110V input wiring.

Either in your owners manual, or on the service door of the furnace there is a wiring diagram which shows the component connections. Serial and model numbers may be there to tell you the transformers power rating.

If you have a new furnace odds are you blew the little 3 amp fuse on the control boaded located in the bottom of your furnace. It should have blown before you let the smoke out of the transformer