waterfilter for eagle cap 1165

I can not make much of your description. The cut line may just as well be the one you use for winterizing with pink antifreeze, or it may not be.

What is the "main valve"?

Does the water system work at all? If not, what is not working?
I may be ignorant of the systems in an eagle cap, but in the campers I have seen, the only filter was a simple mesh filter next to the pump.

A picture or three may help with understanding. If you don't know how to post one, go to this link and follow instructions there:
http://photoposting.is-great.net

I am also confused. What is a 1/4 line? Is that the supply line for the sink and has it been cut?

Why do you think a filter is missing? Is there a filter holder?

If the line is merely cut, then I would get an appropriate connector and splice the line. I don't use a filter on my RV or on the sink. Instead I have a Brita or similar to purify drinking water.

Only reference I saw was in the brochure for that year, nothing in the owners manual. If you received all the documentation with camper might have something for the faucet and/or filter that was used. If there's a loose 1/4" line it may have had drinking water faucet. Generally the filter is tapped off cold line from main faucet, housing mounted under sink. Assume you have an extra hole on sink...

There are many companies that sell complete kits with faucet, filter & housing, necessary fittings to install- under $100. Nothing camper brand specific that would be required to add filter/faucet. If cold main is already tapped with valve one less step.

Curious why someone would remove unless you have whole house filtration.

So I thought there would be a filter for this faucet as it is for drinking water only. looking under the sink the line is cut to the little faucet and has it's sperate water line with a shut off valve for it. I understand that i can put a filter inline where the line is cut to the faucet, I was just hoping someone else had a 1165 and would say yes there should be a filter for that faucet and the filter is a ....... and should be under the sink or should be ....... The kitchen faucet works just fine.

Our ‘07 Eagle Cap has a filtered drinking faucet. Yes, there is a cartridge filter underneath the sink. I think it’s a Culligan but like was said above, you can install whatever you want.

Our faucet looks just like this one: Faucet

OK, I see. This makes more sense.

Thanks wnjj that help! so the filter is missing under the sink, I can proceed to get one now, thanks to everyone else for their input

If you have not found the filter. Check out this one, its whats in mine.
IC10-14C Coconut GAC Inline Water Filter (1/4 FPT)