ORIGINAL: thepamster
Wd-40 is good for stopping squeeking door hinges and not much else. DO NOT spray that on a receiver switch. If your receiver switch contacts are corroded, replace it.
I have seen a lot of people trying to fix things with wd40 in the electronic service industry for years. It creates more problems than it solves.
The Pamster
AMa 202345
Agreed, I would not use WD40 for this but I did have an old '70 Nova that required a squirt of WD40 to dry out the distributor whenever I drove through a puddle. Back to the airplane. I agree that the connectors are corroded. Make sure they are of the gold plated type. If they are gold plated pins, usually pulling them apart and plugging back in a few times cleans them up.