Let's say I start my truck with the temperature on cold. I drive along and then turn my temperature to hot. At that point, no matter what I do, my temperature stays on hot, even if the dial is aimed at cold. I was told by a mechanic friend that I need to remove and lubricate something under the passenger dash. I think he may have said actuator. He also mentioned that I should leave one of the screws out even when I'm done.
Can anyone give me specific instructions on how to this, preferably with pictures?
Thanks.