My car radio looses reception when I pass under bridges. Also, I can hear quite audible "scratching" noise from my speakers every time I step on gas pedal. What is wrong ? How do I correct it ? Thanks for your help. Milo

Have you checked your spark plug wires lately? They can cause static on a radio. Also if your listening to AM it can disappear when under bridges. FM can fade in and out depending on how the antenna is tuned.

Forgot to add: Yes, this happens only with AM stations. Radio sound is replaced with a loud crackling sounds while passing under bridges. FM appears to be fine.

No, I have not checked spark plug wires since - and up to now - I've had no idea which direction to go and where to look. Do you suggest replacing them ? Any specific brand to suggest ?

I always recommend OEM spark plugs and wire sets. But anything that is insulated to help with the radio frequencies (resistor type) will help.