Disconnect both ends of coax. Use continuity tester on one side of the coax cable. If you have continuity between the center and the grounding shield. If so look for a cut in the coax or just replace the coax cable. Not worth messing around looking a problem you can not see. Unless you have xray vision.
may not work on his truck unless he goes into the dash to unhooks the coax from the multiplex box....!
You need to just do away with the stock set up all together. Get yourself the Volvo mounts called bird perches that simply replace one of your mirror mounting bolts and get you a new coax. Volvos have a problem with the ground for antennas but using a bird perch fixes it. I still run mirror antennas on my truck for the fm but there's no way I'd run them on my cb. To much money invested to burn up a radio with faulty antennas
That's what I did. Stopped at Steel Rods got a Volvo perch mount new coax cable and mounted my 4ft Wilson 1000 on the driver side. Completely took off stock antennas since I don't listen to the radio and don't have a tv on the truck. Had the radio peaked and tuned, and the antenna tuned. It all sounds good now. Just wish I could get out further. But not a bad setup for a new driver. My next setup will get me out in 5-7 mile range..
