Swr
1. Check to see if you hear anything without the SWR meter inline. If you do, possibly a bad meter or jumper cable.
2. Check your radio S/RF meter to see if the needle swings upward when you key the radio. If not, check to see if your radio is set to the PA function instead of CB operation. In the PA mode, you may not hear any signals, and your meter may not move, depending on the radio. If the meter moves and you are in the CB mode, your radio may be defective.
3. Although it doesn't seem likely as the problem, try to borrow a mag mount antenna and connect it to your radio and see if there is any difference. If you have a major antenna problem, the radio may be shutting itself down to protect itself from high SWR.
4. Is your power supply up to the job? A stock radio can thrive on a 3 to 5 Amp supply. If you're running an export or higher powered radio, you may need 10 to 20 Amps depending on the radio. Not enough available current equals a radio that doesn't work.
Hope this helps...good luck!
Larry