piety@hplabs.UUCP (Bob Piety) (02/02/84)
Has anyone had trouble maintaining a comfortable temperature inside their Toyotas? I have an '83 4x4 pickup and cannot set the heater temperature properly. There is a large hysteresis in the control action: The temperature gets too warm so you turn it down...it stays too warm, you turn it down some more. Then, suddenly, its completely off and you get cold air. Its also very dependent upon the engine RPM. I took the heater valve apart and noted that the portion of the valve that restricts the flow of hot water is SPRING LOADED????? It seems as though the hysteresis was designed in, for some obscure reason. A friend, with the same type truck, reports the identical problem, although Toyota claims that it is the same heater-valve design they've been using for years, with no complaints. Any suggestions, comments, similar experiences? Thanks in advance. Bob
lat@wbux5.UUCP (02/03/84)
<yumm...this line tastes good [not that kind of line, silly]> I have the same problem with my '83 Toyota Corolla. I don't like a very warm car, but I don't like to freeze either. My drive to school is about 45 minutes each way, all highway. Once I get the car warmed up, I don't need to turn the fan on, just leave the levers on HEAT and WARM, and I am all set...until I start hitting the lights on Route 18. Then, depending in the RPM's, I go from one extreme to another. Usually, I turn the heat on and crack my window, which basically works OK for me. -- Laurie Topor [ihnp4, houxf, mhuxt]!wbux5!lat CSO \ 185 Monmouth Parkway \ West Long Branch, NJ 07733 \ (203)-870-7491
hansen@utah-cs.UUCP (Chuck Hansen) (02/22/84)
I own a '76 Corolla wagon and the heater has two settings: *hot* & off. My solution is to only use the heater on the defroster setting which still blows a bit a hot air on the feets.
terryl@tekchips.UUCP (Terry Laskodi) (03/27/84)
I think I know what the problem is, because my Corolla has the same
problem:
In the back of all the gobble-de-gook for the heater, you'll notice
two copper pipes coming into/out of the compartment. These are the pipes
that supply/take away warm water from the heater. If you follow one of these
pipes, you'll notice it goes into another metal pipe that is T-shaped.
One branch of the T goes into the heater unit itself, and the other branch
looks like it goes somewhere behind the heater unit and somehow gets attached
to the other metal pipe leading out of the compartment. Well, anyways, back
at the T-junction, you'll notice a plunger with some sort of spring attachment
and some sort of lever mechanism. If you move the temperature lever on the
heater, you'll notice this spring/lever mechanism move back and forth. Now my
problem on my Corolla is that the plunger mechanism is either rusty or frozen
somehow, thus only one temperature comes out of my heater. I tested this
assumption by getting a pair of needle-nose pliers and manually moving the
plunger back and forth, and sure enough the air temperature of the heater
did change. Hope this helps some.