Some moisture got into my rania dimmer and it's not coming on now. Do i need to replace the whole thing?

Depending on what line it is, that varies on how hard it is to replace. Being at home, unless you have a vacuum pump to remove moisture from the a/c system, the whole repair will be next to impossible. If you can replace the line, you will need to find a professional shop to evacuate and recharge your a/c system. If you recharge the system without removing moisture it will not cool well.

They're right, you don't want to control the whole thing with a single incandescent dimmer. First of all, the fan-speed and the lights will all be controlled by the same dimmer setting (dim low, low fan-speed - dim high, high fan-speed) - and the dimmer's not rated to control fans anyway which can result in exactly what they said.

There is a Skylark control, the S2-LFSQ- where half the knob controls the light, the other half controls the fan. The only problem you may (and most likely) have is that in order for that to work, between the electrical box for the dimmer and the fan, there needs to be seaparate wire run for the fan, and a separate wire run for the light so that the dimmer can individual control both.

If that's a problem, I recommend the MA-LFQM-, which includes a module that you install in the ceiling with the fan. The wall switch it comes with speaks to that module, and gives you independent control of the fan and light without having to install new wiring. I have one of those myself, I've installed one in one of my friend's houses, and they work pretty well and then you don't have to worry about what wires you've got in your wall.

You are saying that you have a "4-way circuit". That means that you originally had two 3-way switches and at least one 4-way switch. ALL existing mechanical switches _must_ to be replaced with electronic dimmers in order for things to work correctly. You must have only _one_ master dimmer (MA-600) located wherever you desire. All of the other switch locations must be companion dimmers (MA-R)., NOT mechanical switches.

The MAW-603-RH comes with a master dimmer and one companion dimmer, so I suspect that you need to install one more companion dimmer.

the "dimmer switch" is part of the combination switch. They wear down, internally - I've taken apart a used one, so I know. Also, the headlamp connectors like to corrode on that model year ( I also have 96 civic, and had to replace a headlamp connector). https://www.hondapartsnow.com/parts-list/1996-honda-civic-4dr_ex-ka-4at/combination-switch.html (parts 8 and 9)

The question is unclear.
Switches are single-pole or 3-way.
Single pole switches have 2 screws plus green ground screw.
3-way have 3 screws plus green ground screw.
I don't see Lutron rania dimmer
http://www.lutron.com/Products/StandAloneControls/Dimmers-Switches/Pages/DimmersSwitches.aspx

Identify your switch and your dimmer and add a comment.
I will look up the information.

Unfortunately, there really isn't a whole lot you can do here to fix it, any attempt you make to strengthen the grip on the slider may gum up something else in the process. Usually they test for this sort of thing before it leaves the factory so I'm actually quite surprised. The best suggestion I can offer is to call their technical support line (they're available 24/7) and they will probably replace the unit for you.

It's mounted up on the roof and held on with a screw on each end. There's a sticky gasket under it to keep the moisture out. Remove the two screws (usually phillips head, but sometimes torx 20 or 25) and persuade it come (peel essentially) off. Pull it out slowly to reveal the plug and unplug it. It's an LED strip so the whole thing will have to be replaced. Easily located on a popular auction based web site for about $50.

Sounds like your headlight dimmer switch has gone bad and was shorting everything out

You will need to order an HEADLIGHT DIMMER SWITCH

And you have to take the steering column apart (remove air bag and steering wheel) to replace it.

This take special tools and knowledge...if your not sure take it to a pro.

Btw, I’m available to help over the phone in case u need at https://www.6ya.com/expert/sean_54c3a3dc48a7773c

what type of dimmer switch is it.

Did you try adjusting the dimmer switch for the dash lights?