'94 Chevy K3500 6.5 Turbo Diesel
I know this question has been asked before... but... Everytime I start my truck there is a thumping sound under the right side of the dash?

Does anyone remember what it is I have to replace... I have misplaced my brain.

Thanks!

 

You might try checking these threads out and see if what they describe hearing is similar to your problem.

Chevrolet Forum - Chevy Enthusiasts Forums - Search Results

 

Thank you!

I actually did find out what it was... Thank God for Youtube, right?!

Heater Blend Door Actuator

I even found a link to show first hand what is happening...