Being that I have two such modules and neither one works reliably (i.e. sometimes when I go to “dim” headlights the lights just go OUT instead ) I’m going to experiment with one of the modules and see if I can get it working again.
My understanding that what usually goes amiss with these modules is that one of the two mini relays inside the unit goes on the fritz. The other problem is usually a crack in the circuit board (solder).
I’m thinking that if I put the unit in my oven for about 20 minutes or so @ 200-225 degrees I can soften the black “goo” (RTV sealant?) in the unit (similar to the process used when r/ring the fog light lenses) and then be able to slide the circuit board out of the covering for inspection, and then repair whatever is wrong (either re-solder the broken/bad solder or spay/clean up the mini relays with electrical contact cleaner).
Does this sound like a sound approach? I am worried that the heat might damage something else with the unit, but the melting point of tin solder is closer to 400 degrees F. and I have a hunch the plastic cover won’t suffer any ill effects at the proposed temperature. The electronic components should also have no problem with the temp., I would think.