A rear wheel lock up is caused by fluid on the brake shoes. Check the rear wheels for a leaking wheel cylinder or axle seal. Thermostat stuck in closed position. Motor never overheats but runs much warmer than normal. Radiator is partially restricted, and needs to be cleaned or replaced.
Coolant appears foamy and a brown color.
Oil has gotten into the coolant. This is because of a bad headgasket or a cracked cylinder head. There must be a bulb out, check the bulbs on that side. Turn signals come on, but will not blink on either side. The turn signal flasher is bad and needs to be replaced.