Prado and interference on radio

Hi

I have a 120 series with D4D motor. When I have the Engel 40l fridge connected I get significant interference through the radio on AM but not on FM. Went to a electrical contractor and he said nothing could be done to fix this as its a problem with the snesitivity of the radio. (did not happen in when in a GQ Patrol). When in remote locations AM gets more use than FM so its a pain in the A...

There are a lot of Prado's around and so this would have happened before. Anyone have any ideas or ways to fix it?

thanks in anticipation