yet another overheating problem

'90 xj 4wd with the 4.0. here in texas the past couple weeks it has gotten cold. temp is sitting at 24 as i type. about the time it got cold, my jeep started overheating. don't know if the temp has anything to do with it, but i figured i'd throw that out there. my upper radiator hose has no flow. even after letting it idle about 10 minutes and the engine temp shot to around 280, the hose was freezing. according to the records in the car, the thermostat has never been changed (198,000 miles) i had bought a spare thermostat a while back and installed it but it didn't change a thing. after going through all the usual suspects, i found out my e-fan didn't turn on at all the entire time it idled from start to 270 degrees. even though it didn't turn on, i still have no flow through the radiator hose. i plan on replacing the fan tomorrow, but i'm convinced it won't help since i still have no flow.

any insight into this problem?
water pump and e-fan?

Running a 50-50 mix of coolant to water? Failure to do so can result in freezing/slushing of the antifreeze. It's also the best mixture for hot weather. Verify coolant strength with a hydrometer available at any parts store.

Your problem could likely be a disintegrated water pump. I'd consider replacing that while you're digging in Use a NEW pump, not a refurbished one. Replacing the water pumps is not that expensive if you can do the work yourself.

Good suggestions above.

It's possible there is not enough coolant in there or the radiator is frozen (in which case you might be needing a new one soon) if you don't have the right mix of antifreeze.

Does your heater work?

If the radiator doesn't get hot the aux fan will not work on a 87-90 because the temp switch is in the lower left tank on the radiator.