Air won’t blow half the time

Half the time when I cut my truck on the AC/Heat won’t blow any air at all. But I noticed if I hit a bump or if I drop the hood down it will knock it back on sometimes. Any ideas on what this issue would be?

 

Probably the blower motor, next time it doesn't work give the blower a good smack on the bottom and see if it comes on.
If it does the blower is failing, if it doesn't get you a test light and see what your missing and go from there.
https://www.tacomaworld.com/threads/2nd-gen-information-diagnostics.784008/#post-28042158

 

Most likely its your connector, but could be the resistor.

https://www.tacomaworld.com/threads/intermittent-blower-fans-not-working-at-any-speed.741476/

https://www.tacomaworld.com/threads/replacement-of-hvac-blower-motor-resistor.8310/

 

Brushes in blower fan motor could be going bad, smack it with your hand next time. By smacking it you shake the brushes into making better contact, so the fan works for a while

The fan speed resistor is also a common issue, with burned pins at the connector. But usually those don't start working again when smacked

Get under the dash and check the resistor pins for melting

Edit: haha Nav and Dm type faster than me