'97 Venture Van. Fan is not blowing no matter

This is a minor glitch with the vehicle production. Many purchasers have noted this issue...it requires a small correction to wiring...either DIY with a chevy automechanics manual or take it in for minor servicing to fix this minor deficit. Or keep replacing fuses...annoying.

get the sensor checked out.it may not be opening fully

Sounds like one of the blend doors under the dash is not moving.

needs the water system back flushing out, heater being cold is its blocked up some time a few back flushes and forward flushes with a hose pipe should free up the dirt inside, same with the engine and radiator. there are meany videos on you tube to help you understand how to back flush you engie. but do the radiator and engine and heater separate so the muck does not go back into the engine.

Usually a blend door problem, either the control or the blend door itself.

No it's not, if your van is running fine, fuel pump is good, just the fuel gauge sending unit is bad, to repair, the gas tank will have to come off, the sending unit sit on the same hanger the fuel pump is on.

often on the vans with rear air the air dor acuator goed bad and can no longer switch from hot to cold. also the swich itself will often go bad. this can be caused by sticky fingers damaging the inside of the switch. sometimes a good cleaning in warm water will fix a sticky switch

Check the fuse and then the switch it self, if the fuse and switch is good. Then check the blower resistor and blower motor it self. I'm leaning towards the switch it self since you mentioned that it was sporadically and on the highest setting would by pass the blower resistors. Good luck and if it's not the switch then it's going to be the blower motor it self. Auto Zone has them in stock and can give you the step by step instructions for you to get the job done with common tools.

can you be more descriptive? Doe's it only blow on certain fan speeds? send me a messege and let me know a lil more about it and maybe we can solve this problem.

Don't see how one would blow the fuse an not the other . The remote function is controlled by the BCM - body control module or vehicle interface . Regardless ,the module an the switch on the steering wheel both energize the horn relay ! Do you know what a relay is an how it works ?
Check the horn relay

VEHICLE RELAYS Operation Diagnosis