I am installing a new HONEYWELL T8601D2019 - it won't power on.

I realize it needs a control wire connected to the C...
I can not figure out which wire off my transformer is the control.
I have three blue wires, a red, black, and white. Red, black and white are all connected to the unit in some way. Two of the blue wires connect to the unit in some way. The other blue wire is coming from the 24vac but is grounded right next to it (appearing to have not purpose)
Which wire am I connecting to creat the control?
I should mention my yellow is connected to a red wire from a two wire cable the other wire from this cable (white) is connected to a blue cable which is grounded near the 24vac as well. I have connected the blue and white wires to my control wire going to the t-stat already (still no power).

Go to your air handler an see how the low voltage wires are connected.That will let me know how they should be connected at stat

I attached the diagram from the T8600 series stat, and I do not see a terminal C.

C is normally a return for stat with builtin clocks or some other device that needs power in the stat.

Perhaps , if you only have one transformer, then you must install a wire jumper between R and Rc.

Any possibility of getting a couple of pictures? Will help greatly for us to fiquire out what you have.

Here are the specs for the T8601D2019

Premier White® 7 Day Programmable Chronotherm® IV Plus Thermostat with automatic/manual changeover, 1 Heat/1 Cool stages and R,C,B,W,O,Y,G,OT,OT terminals for gas, oil, electric or heat pump systems

http://customer.honeywell.com/honeywell/ProductInfo.aspx/T8601D2019

As for the transformer, I would be better off if I could draw a diagram. I searched online to try to find one like mine, but didn't have any luck.

I thought upgrading a thermostat would be easy (silly me!)

OK how did you get what you have so far from Honeywell site? I did a search for your stat , and as usual, no results. Of course, now off your link I still cannot get to the installation instructions to see the actual diagram.

The diagram I did find came off a third party site, and is only for the series. I was hoping the diagram was for your stat.

The R & C is the 24 volt power from the transformer, the hot and return. IF you can trace R back to the transformer, the C is the other terminal opposite R on the transformer.

Does this help at all?

I cannot tell by your wires color code because someone used non standard wire colors and multiple cables.

Can you scan your wiring diagram of your new stat and post it here? Or download the instructions from Honeywell? The damn site never works for me.

If you do provide a sketch of your transfomer, can you show what each wires is for?

To find the instructions on the honeywell site, you just follow the link I posted, and at the bottom of the page, there is a scroll through of PDF's the manual and instructions can be downloaded from there.

As for the transformer - my red that is coming from the t-stat doesn't dirrectly connect to the 24vac, it connects to a red coming from the circuit board...
I do have a blue opposite the red on my transformer, and I tried hooking that up to the common wire, but got nothing.
I'm sure there is a simple fix to my problem, but so far it has been very frustrating. I thought these things were plug and go! LOL!