Heater fan and turn signals problems on 2001 Impala

My son's 2001 Impala has had some problems with the heater motor either not working or not shutting off. Now it has killed the battery. He had shut the key off, locked it up, but when he went out to start it today, the fan had run until it killed the battery. He has also had problems with his signals working intermitantly, but not sure if this is related. Has anyone experienced similar problems?
Shel

Modt like the blower relay /resistor, not positive about the location but usually on the blower case under the r/s of the dash.

Thanks. It turns out it was the relay, and at least the heater fan problem is fixed. He forgot to ask about the signals, so that issue will have to be dealt with another time.
shel