Blower motor 2000 kia sephia works and stops when it wants

When the blower stops working hit the motor with something, if it starts you will need to replace the heater blower motor, the brushes are worn out.

need to replace blower motor....behind glove compartment....I also have a kia sephia 2000 had same problem....

sound like you need a new blower motor.

just offering advice on a general application for a broad number of vehicles as im not sure where your blower motor is.
car manufacturers know that the blower motor gets used as much as the radio, so they generally make it easy to remove and reinstall.
if you have the new blower motor , look under the hood for a part that looks like that one sometimes they put it under the passenger side dash
. also look at that new part and count the holes on the flat part and its usually 3 or 4 retaining screws that go thru the holes
find out where yours is on your car, and look for the screws that are holding it into place. those need to be unscrewed
its normally pretty simple to remove the retaining screws and unplugging the wire connector, then pull the motor and fan blade assembly out of the hole . now you most likely have to remove the fan blades and put them on your new motor. sometimes its a clip holding the fan blades on, sometimes its just a nut that has to be taken loose.
put the fan blades on your new motor , put the motor back in place and put the screws back in place and plug it back in.

First thing i would do is unplug the old fan connector, and if you can get the new fan close enough to the connector, plug the new motor in the connector and see if it spins ( before you try to take the old one out)
if it spins , then the problem is defianately a bad motor and you need to switch it out

Find the relay for the Blower Motor and check it.

your blower is finally going replace it

need to replace blower motor.

Most probable worn out blower motor sometimes you can jar or bump motor and it will work some.

i did the same i think heres a short some where costly to fix i ran a hot wire from the battery to the motor and my switch works fine

I had the same problem, started about 150K miles. It had nothing to do with the fan motor or the switch. my problem was under the fuse box. it was shorting out and i couldn't figure out how to get the wire out or wedge it in to where it would hold, so i got an external inline fuse and bypassed fuse box. when doing that it bypassed the relay as well. by hey, the fan blower works now.