Elec. problems 74 Dart

Hi @ all...

My project is terrorising me...

The car is allmost done - and thanks to FABO I could fix a lot of problems, but today we noticed two new ones...

Problem 1: the stop-lights aren't working. I don't know if we've done something wrong while wiring, we checked it twice, but we can't find the cause. We replaced the stop-light-switch, controlled the plugs and sockets - nothing... Any idea? Maybe a relay? It's my first american car, so I'm really helpless...

Problem 2: the temperature-gauge isn't working. We checked the fuses, replaced the sensor, nothing helps. Here too: Any idea? Maybe the gauge itself? And if it is broken - where to get a new one and how to replace it?

Thx...