1992 accord cooling problem
 

My accord has been running hot, not the engine, but the temp gauge. I bought a new thermostat last night went to put it in and nothing was there, I know some people think the thermostat is in the front off the top radiator hose. Well, anyway no thermostat and the electric plug that goes into the thermostat housing had some sort of diode in it and it wasn’t connected. I put the thermostat in and reconnected the electrical part to the thermostat housing and almost right away when i started the car, the temp gauge said hot. I let it idle for awhile and the engine or coolant wasn't hotter than normal. I drove to work today with the ac on and still not hotter than normal, but the gauge says so. now what do i do?

Thanks