Hello all. I have an 08 prerunner. It's started blowing cold when the heater is on but only at idle and it's intermittent. My coolant level is good. I suspect the thermostat but would like some input from others before I change it. Any other opinions? I also have halo headlights installed and my left connector keeps vibrating loose. We (me and the guys at my shop) have reconnected and used things to keep them from coming loose and they always do. Any advice for that? Thanks in advance.

 

for the wire.. strip it, solder it, shrink wrap it

 

OK thanks!