How's that for a definitive answer? Actually, I'm very familiar with that problem in the mid '90s when working at a very nice family-owned Chrysler dealership. There was a rubber cover to pop loose under the dash, then the rubber seal could be pulled back with a cotter pin pick. That's a pick with a screwdriver handle, and the pick has a 90 degree bend on the end. I used Chrysler's "Spray White Lube", but other manufacturers have the same stuff under their own name. That stuff works well because it sprays on very runny. The juice runs into tight places and takes the grease with it, then the liquid evaporates and leaves the grease behind. (Works real well for noisy door hinges). I solved the noise on about a dozen cars, but on those, the noise usually went away in warm weather. Winter was when they acted up the most because the previous grease became hard and ineffective.
Since you observed the noise is related to moisture, I have a suspicion water is hitting the seal from under the car. Due to ease of access, I'd look under the dash first, but you may have better luck getting to the seal from under the car. In my experience, just spraying grease at it will not be a permanent solution. You need to get the grease under the seal, and that means pulling it up in one spot.
Friday, May 26th, 2017 AT 4:37 PM