Be sure to get the right kind of Anti-freeze cuz some cars use Cool-Tex (orange) Antifreeze while other use Green antifreeze. Refer to Owner's manual (typically in maintenace care nearly end of the book). If you are not sure, ask Auto part store to find out which Antifreeze type your car is using. There are time that some people don't bother checking Antifreeze in their car and it reach over 100k miles then suddenly they complained that their heater don't work or works only if they driving after stop. Antifreeze evapoates over the time until it runs low without any leaks. My friend drive 2003 Chrystler Town & Country, she asked me to fix/tune up her car before her vacation. It had 122k miles on it. She complained about heater not working. I checked through her car and
her van was low on Antifreeze. I decide to replace Thermosat before filling up the antifreeze. It use Cool-Tex (orange) antifreeze that I have on hand cuz I own Dodge Durango and Jeep Liberty that uses same kind. I happily fill it up and now heater works great.
Plus I fixed her tranny that had leaks. She told me she sent it to mechanic several times and they couldn't fix it and told her get a new tranny (she spent hundreds of dollars each visit yike!!). It was one spot of seal near wheel well apparently got damaged by rock or hard objects on highway. I simply put Gasket Maker (blue silicone sealer) on tranny seal lip where leak came from and on portion of rubber gasket plus the portion of pan. I let it dry a bit before putting pan back on tranny. I fixed the leak for good. Unbelievable!! Mechanics don't clean out the dirt and grimes to find the leak coming from!!
Be sure that you have right kind of tranny fluid such as Mercon-Dexron, ATF, ATF +4 (ATF +4 typically Dodge or Chrystler). If you don't use right kind, you'll damage the tranny. Refer to Owner's manual or Ask Auto part store
So when you check your car, OFC, check oil, brake fluid, tranny fluid (checking tranny fluid requires engine running and car on Park), Air pressure on each tires, and Lastly, antifreeze. The white semi-transparent container usually hold antifreeze that have marking "Max -- Min--) level. Check to see if you can see liquid line on the container. If you don't see any, Open the cap and look inside if you can. If you don't see any Antifreeze, just fill it up to Max-- level , don't go over it.. Check again after engine is hot and running. If it still low cuz the engine "suck" the antifreeze to fill the radiator, wait 30 min and if level on canister still low, fill em up to Max level again. Until engine stopped "sucking" antifreeze..
Also either you or your hubby or friend check sparkplugs to be sure it's still in good shape. Cheap Copper core sparkplugs requires 3,500 mi replacement while Platinum Sparkplugs requires 24k miles to replace ( I prefer Platinum cuz it last longer. I usually get Bosch 1 tip Platinum sparkplugs)
You do likewise if you are travelling long trip. Typically, cars or truck do lose oil, fluid during long trip because engine work very hard on high speed on highway even brand new car/truck. Be sure to check every 500 to 1,000 miles interval on your long trip (during time when you're filling up gas). So that you'll keep car well maintained.
Also check air pressure if you happen to drive through the West (Colorado, Utah, and several Western states) that Atmospheric pressure are different. Like for example, Going from Colorado to Salt Lake City, Utah which is under Sea Level, It cause the tire pressure to go down 5 to 10 PSI. Fill em up to correct pressure. When you leave Salt Lake City, UT, driving up the long hill and arrive to Colorado, be sure to check pressure again, It'll go over 5 to 10 PSI that could lead blowout. Leak out the tire to correct PSI level. It did happen to my old Mazda 323 when I drove to West and head back. I kept checking tire pressure cuz I saw many cars and truck had blowouts and was pulled over to side of highway (it was during summer time). That explained why it happened. It's just my common sense thing.
Lastly, you might want to check brake pads to be sure it's thick (Typically any cars or truck that have disc brakes on front or all 4 wheels). If you happen to own a car with Mag spoke wheel, sometime you can peek through or feel it (only if disc are cool) to see how thick without removing wheel (if you can't see it on one or two wheels, just move your car few inches to rotate wheel). If you see brake pads are thin, replace it ASAP before it scoures the disc.
These are basic checkups you need to maintain your car.
Catty
I know how to check oil and such, but I honestly didn't know about anti-freeze. Anyway, this may explain why I no longer have heat in my car. I'm currently stuck in a blizzard in NY. 
