Heat Not Working - What am I missing?

[testerdahl]

Spent a bit of time yesterday and today working the heater. I feel like I'm missing something, but I'm not sure what it is yet.

I bought a new motor and a new resistor. Today, I troubleshooted the wiring to discover a bad power connection at the switch. I snipped off the factory plug and connected with new connectors. The fan works and the switches work as best as I can tell. I ordered a new heater core today and will be here tomorrow.

If it isn't the heater core, any other ideas on things I can work on. Here's a few pics of the wiring I got to work.