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So does the water valve actually operate correctly from the vacuum actuator (by default it should be open without vacuum), however it is possible it is always closed with the engine running... Worth investigating
Alan
Read what I said before ^^
What you said makes no sense... if there was no vacuum going to the solenoid valves then you should have had a hot heater core - the water valve defaults to open = flowing hot water to the heater core. Even with the mixing flaps closed you should get some heat...? Something is up... dig in.
OK let me try again...I suspect that the water valve is working fine (it did before I installed it on the car, for sure) but that the temp mix flaps are not allowing any air to pass through the heater core and into the cabin, despite the settings motor lever moving. I suspect (haven't checked) that the arm is moving but not moving the flaps.
Now that I suddenly have a functional vacuum system, my vacuum actuator-controlled flaps are working, and presumably the heater valve too, but if that lever arm on the settings motor isn't moving the temp mix flaps, there'll never be any warm air coming into the cabin...which is just fine, for me, right now.
Does that make more sense? If not, then I am misunderstanding something here...
Does that make more sense? If not, then I am misunderstanding something here...
Not to me.
A big hunk of engine heated metal in the HVAC box means you will get some heat even with the flaps fully closed. I'm not sure what Greg meant in his post before -but the heater core will cool down quite quickly with airflow and the water valve closed. The water valve closed means no flow/no heat. The mixing flaps don't seal up that tight - they just control the % of flow through the heater core. The comb flap is to bypass the whole heater core area for the console air to avoid this warming when you first select max AC (or close to it). Turning the water valve off eventually gets you the coolest air elsewhere too.
Once the car shuts down of course the water valve will open and the heater core will quickly get hot again due to gravity circulation and no air flow - this is why you get a blast of hot air after parking the car for a little bit - even with AC on full (bit of a design flaw - but likely just oriented more to cold weather countries...).
Something is not right here - maybe it's just the mixing flaps stuck - but I suspect a water valve issue too - maybe it does have permanent vacuum applied - trace the line...
Ahh. OK, I see what you're saying. I will dig further then....that water valve was definitely working out of the car with a Mity-vac, so I'll figure out where that line is actually going...
my vacuum lines, solenoids, actuators are all working as they should. (I went thru complete system last year with most components replaced)
heater valve works properly with temp slider movement, but comb filter and fresh air solenoids are not getting proper signal. OP was regarding setting motor
and I wonder if that is my issue? motor lever arm works, albeit slowly, with temp slider movement.
pretty sure I have an issue with my setting motor. here are pictures of one of the boards. this does not look good to me.
anyone been inside these want to comment?
I'm sorry to say I can't remember well enough...the circled area does look dodgy, but I don't think the trace is actually broken, is it? I had an area on mine where it looked like there was a broken trace that had been solder--blobbed, and then the blob fell off. One thing I found useful was ohming out the traces to check that they were still viable. In this case, however, the suspicious area is at the end, so that's not going to be so helpful.
performed all of the tests in WSM and while my setting motor has smooth full range of motion, it stays at either full cool from 65 all the way up until just below 85 and then goes to full heat. there is no middle ground?
the signal voltage is not being regulated? at full cold, no signal is making its way to the fresh air flap, and at full heat comb filter is not closing?
when testing there is suppose to be a voltage change by 10 to 20% on some of the connections, at certain changes with the head unit temp slider. is that voltage modulated by the setting motor internally, or by the connection from the head unit?
it appears that the setting motor has 2 (semi) unrelated circuit boards that perform 2 distinct different jobs. here is the other board
this is the larger of the 2 boards and receives signals from the temp sensors and WSM testing reveals it operates correctly with ohms from 3.7k to 4.7k with temp slider from cold to hot. but I think the reading should be variable from one end to the other. is that correct? my blender arm is either full cold or full hot. according to WSM this part of circuit should be fine
the smaller board is responsible for the recirc flap, comb flap, and heater valve. my heater valve works fine, but no comb or recirc
yes. signal is good, but WSM says it need to be modulated and it is not. if modulation takes place in the head unit,
then that's my issue, but I think the wipers inside the setting motor controls that. just need to be sure before I start
throwing cash.
possible unique to my situation, but wanted to pass along for anyone inclined to dig into the control units. to recap, I had a compound problem which included my recirculation/fresh air flap working properly with car running and head unit in off position, but NOT working with AC compressor engaged along with defrost. also, my setting motor would only work in full open (hot) or full closed (cold). I went thru all the basics test for vacuum at solenoids, as well as using the WSM to run thru the connections on both the control unit and the setting motor. pins 8 and 9 on the head unit were suspect. when I applied power to pin 8, there was no continuity at pin 9. a poor solder joint at the board solved all of the above. the joint was not visibly bad. very surprised that this repair solved both the recirc flap issue, as well as the setting motor which not has correct arrange of motion, stopping at variable points along its travel.
08-27-2016, 07:21 PM
