Truck getting hot

I have a 1994 Toyota Pickup with 250,000 miles and it still runs well. The problem is that it gets close to overheating when running with the AC on after about 30-45 minutes of driving. If the AC is off it runs at normal operating temp. Most of my commute is on the highway. I think it could be the belts and/or the radiator fan.

could also be a partially plugged coolant hose or radiator. It allows enough fluid through to keep the car in normal temp under regular driving loads, but the AC ads enough heat to the system that it can’t keep up.

I do not think your problem is the radiator fan since the problem occurs on your highway commute. For the same reason, I doubt that it is the belts. What seems to be happening is that the radiator is not removing the heat as it should. The repair may be as simple as taking a garden hose and spraying through the radiator honeycomb from the engine side out through the grill to remove dead bugs and other highway debris. If this doesn’t cure the problem, then have a radiator shop check the radiator. The internal passages could be partially plugged.