Interior coolant leak

[Collapsedsuspension]

Hi, month 3 of my new to me Berlingo and yet another problem crops up!

I've just fitted a new interior fan after the old one packed up on holiday in 30 degree heat  

Now I have a small coolant (I hope):leak. The first sign of this was a few weeks ago with a strange grassy smell. It is a very small leak and the carpet is hardly wet at all, though it has been leaking at least 3 weeks. The heater matrix was actually replaced just over two years ago so I'm hoping it's a joint rather than the matrix itself. The fluid is cold even after running the engine up to temp, though the heat is on full cold owning to it being summer (will see tomorrow what happens when I turn on the heat).

Here are some pics showing where the leak is coming from (where I point)
https://m.imgur.com/a/ZJwDK

The area around the leak is stained with precipitate.

So to my questions: what pipes run in that area? Any joints near there? Is there any way of assessing the pipes without the dash removal required for replacing the matrix?
Car is 1.6 petrol, manual with A/C.

[oilyrag]

Could it be condensate from the A/C rather than coolant ?....but if it is coolant it's a low cost, low labour option to try something like this - barsleaks.com/product/radiator-stop-leak-concentrate/

[Collapsedsuspension]

The liquid has a slight oily feel like a coolant/water mix would. I need to sample the coolant to see if it smells the same and leaves the same precipitate when it evaporates. Hoping it isn't the A/C refrigerant leaking (A/C performance is good)

[Tomcat3]

If its a coolant leak in the cabin it usually smells a bit like curry. There are quite a few threads on here about it and an how to replace the heater matrix.