Greetings from a wintery Melbourne, Australia.
It's getting cold so it's time to get the heating working properly. My issue was that the car would go both to HI and LO on the temp controller but not hold correct temp in between. All checks done on the HEVAC test page and all seemed well. Blowers, fuse box and blend motors all OK. I fixed them all up a year or so ago. Temp distribution motors working OK. All flaps in the heater box working and free but the book symbol on.
So I did a test: how long does it take for the book to light up? I ran four tests and timed it with a stopwatch: exactly five minutes each time, regardless of whether or not I moved any of the temp settings or adjusted the distribution motor. I figured the system is doing a test, but what's it checking? The coolant temp of course; five minutes is enough to get the coolant up to temp from cold.
Bought a replacement from my wrecker Matar Motors in Melbourne (Derek; great guy for second hand parts) and now I have NO book symbol for the first time since owning the car. Yes I know. Small things amuse small minds. But it's fun to have the car working.
Funny how I could find no other reference to the five minute self test.
Let's look at the options:
1) Drive the car with it not functioning correctly. Yuck! How low-rent and distasteful. These cars are grand. Get them going correctly with the help of RR.net.
2) Sell the car and buy another car. Well if I wanted another car I would buy another car. Simple as that. I like this one, plus I have a late model Mercedes SL500. I believe automotive perfection is obtained with one serious four wheel drive and one serious sports car/cruiser. How could that situation be improved? Not possible.
3) FIX the car properly with the help of RR.net and doing proper diagnosis by elimination or with the right tools (still thinking about buying a Nanocom. They're expensive and second hand parts are cheap).
What is the temperature sensor spike that slides into the heater box on the bottom; It's about six inches long. I couldn't find any reference to it. What does it do and do they fail?