I know this thread is 6 months old but if you’re still having problems, or if someone else is having similar problems then you will need to isolate this issue to track it down. It does
not necessarily have to be an electrical issue. Here are some simple tests that will put you on the right track. Face your detector 180 degrees from where it normally is. You’ll probably not notice any difference but this is troubleshooting, and it will help you to narrow down what is causing your issue. Next you need to isolate your electrical system. You do this by running wires to the detector that are coming from
another 12 volt source (a second battery, a second car, etc.). If you have a old A.M. transistor radio then put it at a frequency where no radio signal is active. Turn up the volume. Now go WOT and see if the pitch of the static changes. Have someone else go WOT while you -
carefully - move the radio around in your engine compartment (
please be very careful while doing this). Listen for a higher pitch. Don’t forget about looking at the ground. A lot of times in a lot of cars they have a ‘false’ ground where it will test as ground
but will be isolated further down the line. Run a ground wire from the frame of the car or the battery ground to the detector ground and test it again. Also, don’t rule out that there could be an issue with the detector itself. Try it in another car. All of these tests will tell you something that will help you to diagnose it further. Good luck
Interesting 
Linear Mode
