Question Description
1994 chevy 1500 ext.cab every time i turn the key on and start the truck a tapping sound starts and taps for 30 secs. also when i turn off the truck the same thing happens.the sound is near the heater box under the dashboard.

Final Answer

It sounds like either you have some debris in the blower motor fan, or the blower motor going bad. That or a lifter in the motor could cause a ticking noise.
