dont have any heat in truck already replaced thermostat

Here is some info about what can cause this issue: http://repairpal.com/i-have-no-heat-what-could-be-wrong If you cannot find the components for the heater system, I suggest you get a good repair manual and read up on the system to familiarize yourself with it. You might find a free repair manual here: http://bit.ly/autozone_repair_info or go to http://bit.ly/alldata_repair_manuals or http://bit.ly/mitchell_repair_manuals_online and get an online repair manual subscription.

DID YOU TURN THE HEAT ON?

Chevy vents are designed to be a perfect mouse house, they always build it near the heater blower and you have to weasel out the blower housing by prying up the unidash under the glove box, after removing the screws (make sure it is in the off position).