another hvac question
#21
probably another dumb question, when you say mode switch, do you mean the mode selectors with the temp dial, speed (1-4) and mode selector?
there is a slow hiss noise when switching modes from the one to another. not sure if thats normal.
there is a slow hiss noise when switching modes from the one to another. not sure if thats normal.
#22
The mode switch is the dial that you turn to select where you want the airflow to come out.
The hiss noise between modes is normal, but it should stop very shortly after you make the selection. When you change selections, some of the actuators need to vent the vacuum that was applied to them.
The hiss noise between modes is normal, but it should stop very shortly after you make the selection. When you change selections, some of the actuators need to vent the vacuum that was applied to them.
#23
The mode switch is the dial that you turn to select where you want the airflow to come out.
The hiss noise between modes is normal, but it should stop very shortly after you make the selection. When you change selections, some of the actuators need to vent the vacuum that was applied to them.
The hiss noise between modes is normal, but it should stop very shortly after you make the selection. When you change selections, some of the actuators need to vent the vacuum that was applied to them.
also if it is the mode switch, do i need to replace the entire hvac control unit or just a specific part? and part number if available
#24
Checking each individual line at the vacuum line connector will double check the lines and the actuators, good idea. Each one should hold vacuum. If you find one that doesn't, post what color it is. Then we can do one more test to make sure the mode switch is faulty. Once we figure out where the problem is, then we can get part numbers
#25
Checking each individual line at the vacuum line connector will double check the lines and the actuators, good idea. Each one should hold vacuum. If you find one that doesn't, post what color it is. Then we can do one more test to make sure the mode switch is faulty. Once we figure out where the problem is, then we can get part numbers
what should i look at next?
#26
Losing 4 or 5 inches of vacuum after 10 minutes is not real serious, and probably not the root cause. If it loses vacuum rapidly going through the mode switch, that's most likely the problem.
Yellow goes to the mode valve actuator. It's a 2 position actuator above the gas pedal. There are two actuators there, and it's the top one. The brown also goes to it, and to the slave actuator. That one is on top of the heater case and involves taking the dash apart to get to it. If you apply vacuum to the yellow line, and kink the brown off at the slave, that will tell which one is leaking. Might not hurt to try to narrow it down.
Yellow goes to the mode valve actuator. It's a 2 position actuator above the gas pedal. There are two actuators there, and it's the top one. The brown also goes to it, and to the slave actuator. That one is on top of the heater case and involves taking the dash apart to get to it. If you apply vacuum to the yellow line, and kink the brown off at the slave, that will tell which one is leaking. Might not hurt to try to narrow it down.
#27
thatll most likely be another day testing the brown and yellow , you also mentioned testing the mode switch, how should i go about doing that?
#28
Connect the vacuum pump to the port that the black line connects to on the mode switch. Select BLEND and apply vacuum, it must hold. It not, the mode switch is faulty.
Last edited by Captain Hook; 04-01-2015 at 08:59 PM.
#29
vacuum fizzes right out of it, wont even hold. vacuum line is nice and snug
and just clarifying when you say bi-level, you mean floor and vent mode which is has a line connecting it to ac and max ac
#30
Floor and windshield on the icon. If the black port does not hold, you found the problem.
Last edited by Captain Hook; 04-01-2015 at 09:00 PM.