Time for some basic trouble shooting
The Midland 1001z is an AM (amplitude modulated) radio. This means that the transmitter carrier wave varies in strength in proportion to the volume of the transmitted audio signal (your voice) and how quickly the carrier wave strength is varied matches the frequency of the transmitted audio signal. So to transmit a good quality signal the radio needs to put out a well modulated high power signal.
Sounds like you do not have a lot of test equipment so let's try this. Find a buddy with a good working CB and take your radio to where his radio is. Then:
1) Make a radio test on his radio, to prove that his radio is working.
2) Disconnect the coax cable from the back of his radio and connect it to your radio.
3) Make a radio check with your radio.
If your radio does not pass, then the issue is with your radio.
If the radio does pass then the issue is either your installation or antenna system. So then back at your truck, are you getting the expected 13.8 VDC to power the radio? Check this when you are transmitting. If that is good then the issue is with your antenna system which is defined as everything from your radio's coax connector to and including the antenna.
You have to be systematic, so now we are trying to determine if the issue is with the radio or not.