2003 EV engine coolant sensor/radiator fan issues?

[ErinB]

I'm certain this has been discussed somewhere here before, but I can't find anything similar right now and we need help! So my apologies for lengthy post/question - but we have a few things going on....

We purchased a 2003 Eurovan MV Weekender about 3 weeks ago and everything has been fine until a few days ago when the engine coolant/temp warning light started flashing and beeping every morning when car is first started. No worries here...read up on that and learned this is common when car is first started; but recently it has begun flashing and beeping at random times throughout the day. I've also thought the radiator fan (I'm assuming it's the radiator fan) seems to run frequently (it has always done this from the day we brought it home). It doesn't often run for long periods of time, but it runs a LOT.

Today when I got to work I noticed fan running as I walked into office. 10 hours later I returned to start car only to find a dead battery! Jumped it fine, but I noticed when I first attached jumper cables the fan immediately clicked on before I even tried to start car. Car started up and fan turned off shortly thereafter. I'm assuming the radiator fan ran for a few hours and drained the battery. Engine coolant sensor beeped at me a few times on drive home. I did check the coolant level as I was jumping the car and it seemed a tiny bit below the MIN line, so it looks like I need to add coolant. I have been VERY confused about what KIND of coolant to add - owner's manual seems to indicate it can only come from a VW dealer, but online research says otherwise, and that I can't mix G12 with G11, and to check the color, etc etc. It seems overly complicated....

Side note: A/C blows HOT - not just slightly warm or cool air, but HOT air for AT LEAST 15 minutes of average driving before it then turns quite cold and runs fine (until car is turned off, then entire process starts again, even if car is off for just 20-30 mins).

I'm assuming all these are inter-related; have done lots of Googling and reading here and on GoWesty and similar forums, but not coming up with anything concrete. Worried I may have a sensor problem, yet don't know how to test, and don't know what kind of coolant to add, most importantly.

Any feedback would be most welcome, as my husband and I are newbie EV owners and of course are nervous seeing that van is only 3 weeks old to us! It has 138,000 mi, and I do not notice any fluid leaks in driveway where I park it every day. It's my daily driver - yay!

Thanks so much!
Erin