Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 9/27/83; site hplabs.UUCP Path: utzoo!watmath!clyde!floyd!harpo!seismo!hao!hplabs!piety From: piety@hplabs.UUCP (Bob Piety) Newsgroups: net.auto Subject: Toyota Heater problems Message-ID: <2175@hplabs.UUCP> Date: Thu, 2-Feb-84 15:46:45 EST Article-I.D.: hplabs.2175 Posted: Thu Feb 2 15:46:45 1984 Date-Received: Wed, 8-Feb-84 03:08:31 EST Organization: Hewlett Packard Labs, Palo Alto CA Lines: 21 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