I have a 1999 cat 312B, 9HR00818. The cab has no heat. The engine temp gets warm (see attached picture) but the air coming out of the vents never seems to get warmer. Changing vent settings and temp settings doesn’t seem to make a difference. I checked around the motor and couldn’t outwardly see any heater shutoff valve. Also, I can hear things clicking when adjusting temperature and vent setting, so everything from the control panel seems to be working. The blower motor is working and adjusts speed when the buttons are pressed. Not sure what this excavator has in the world of blend doors/actuators. Also attached is a picture of the heat control unit so you all know what I’m dealing with. Any help is appreciated. Thanks.
5I-3586 @ $200 #35
Looking this up, it says it’s a clip, and that it’s discontinued. Do you have any info on the part, more so what it’s controlling, maybe a picture of the part specifically, where to find it, perhaps? Thanks.
Sorry, transpose.
Great thanks! Are these a common valve that goes out and prevents coolant flow? Is there any good way of testing it before replacing. Thanks again.
I found that valve, and the motor that controls it is not working. I disconnected it and manually adjusted the valve open, however after again getting the machine warm, I still had no heat. After looking, The valve itself where coolant should come into the cab, through the valve, and into and out of the heater core are all still cold.
Then, perhaps it has a shutoff valve at either or both locations circled.
Trace the lines from the engine to the core. Looking for a kink or even valves. I worked on a 311DRR that someone had installed ball valves in both heater lines under the cab only accessible by removing the bottom pan.