One problem related to vehicle overheat has been reported for the 1999 Dodge Ram 1500. The most recently reported issues are listed below.
I have owned two 1999 Dodge Ram 1500 pickups. One had a 5. 9l and one had a 5. 2l. Both vehicles experienced a failure of the ventilation servo (switches cold-warm-hot air mix) and both experience cracked heads. All occurrences happened between 90,000 miles and 100,000 miles. As for the cracked heads neither vehicle had ever overheated, and had always actually run fairly cool.