Well, In your shoes I'd pressure-test the cooling system and possibly do a pressure leak-down test of each cylinder, pressurizing with an air compressor and seeing if that pressure is lost, and if so, trying to figure out if it's out through somewhere that could be the head gasket.
I did some Internet searching, and it does not sound like the temp ranges that you mention are really all that out-of-whack for normal driving. Remember, there are a lot of thermostats that do not even open up until 160°F, 180°F, or higher.
It's possible that there's a coolant temp sensor problem, rather than an actual fault. I don't know how the Suzuki save-the-engine systems work with regard to temperature and electronically cutting off the air conditioning. I would hope that if there is a fault that causes the computer to cut off the AC that it'd store a code in the process.
Unfortunately Dad's '99 Chevy Tracker is the 4cyl, so there's not a lot that I can suggest that direction.
Has the coolant ever been changed, and if not, what kind of coolant is it?
I did some Internet searching, and it does not sound like the temp ranges that you mention are really all that out-of-whack for normal driving. Remember, there are a lot of thermostats that do not even open up until 160°F, 180°F, or higher.
It's possible that there's a coolant temp sensor problem, rather than an actual fault. I don't know how the Suzuki save-the-engine systems work with regard to temperature and electronically cutting off the air conditioning. I would hope that if there is a fault that causes the computer to cut off the AC that it'd store a code in the process.
Unfortunately Dad's '99 Chevy Tracker is the 4cyl, so there's not a lot that I can suggest that direction.
Has the coolant ever been changed, and if not, what kind of coolant is it?