Bought my mazda 626 with approx. 70,000 miles. This problem has been intermitent for a year. I have a '98 626 about 98000 miles now. Had a timing belt replaced about a year ago. After that the ac went out. 4 months later on a snowy winter day the alternator seemed to go and battery was the original so replaced them both. It over heated some at that time. After everything seemed fine except the belts kept squeeling. The temp went up about 2 months after alternator. So had belts tightened and replaced thermostat. Belt broke, took it to original mechanic who did the alternator. He fixed it no charge. And all had been well for 6 months. Belts are starting to squeel again. Driving at approximately 60mph & may car temp is going up so I pull over stop and check to see that belts are turning. Check to make sure coolant is ok. Temp gage is back down so I drive home slowly. Temp goes up if I accelerate much. But all of my electrical systems are shutting down so I shut everything off except the lights. The start getting dim and the battery light comes on. I keep driving them the check engine light comes on. I limp home but wil listen to any advice.

Have the size of the belts verified and the pulley alignment checked. The most likely cause is the belts are slipping and not driving the water pump under load.