1999 van over heats

[2fat2old2slo]

My 1999 dodge ram van overheats when the ac is on and it is at highway speeds. If you turn the ac off the temp drops.

[restrorob]

Originally Posted by 2fat2old2slo

My 1999 dodge ram van overheats when the ac is on and it is at highway speeds. If you turn the ac off the temp drops.

Check the fan blade clutch it may not be pulling enough air with the added heat from the ac condenser,It should be pulling a considerate amount of air.
Just had the same problem on a jeep.

[fredjacksonsan]

If the fan is ok, I'd look into replacing the radiator; even a small restriction will cause the problem you're experiencing.