The everlasting HVAC problem

[abscate]

thanks for the reply. the sensor is free of any dust and crap that might get down there. and the fan moves freely. and it didn't help. did that about 1 year ago now.

looks to me that i just have to set a side a weekend to start digging into the dashboard :/
oh well. just another thing to add to the list. i've got a complete timingbelt job on my list too

is there any way of checking the sensor? in my world (vw golf mk2 world). we've got the infamous "blue" tempsensor. its possible to readout the resistance at a given tempereture to check if its within the threshold.

don't know what kind of sensor the cabin air temp sensor is (thermistor?). if so it should be doable. if it exist a chart of known good values

Found it for ya.... Jubel!!!

Heres the outside air temp specs, too - this one sits down in the climate system, inside the car, next to the fan.

Screen Shot 2017-09-13 at 6.23.18 PM.png (26.35 KiB) Viewed 1554 times

[sleddriver]

Hmmm...my post didn't make it here either due to MVS server 'not responding' issue as with other post.

OP: Look back through my previous posts re: ECC on how I troubleshooted my damper motors. You may find something useful before you choose to remove the dash.

[dsno]

Which sensor are you talking about when you say down there? There is a sensor beside the fan/resistor pack monitoring incoming air I believe, and then there is the one in behind the dash up to the left of the ECC control unit as shown in my link. If that one is 'working' they do go bad and can info can be scanned by Volvo/Vida. I had that issue with a 98 V70XC and replacing it fixed the issue. As to the specs., not sure I have ever seen anything on that part.

Neil.

i was talking about the cabin sensor with the fan didn't know there was any more sensors to this system, nut now i do. so i'll try to check this over the weekend

[dsno]

Which sensor are you talking about when you say down there? There is a sensor beside the fan/resistor pack monitoring incoming air I believe, and then there is the one in behind the dash up to the left of the ECC control unit as shown in my link. If that one is 'working' they do go bad and can info can be scanned by Volvo/Vida. I had that issue with a 98 V70XC and replacing it fixed the issue. As to the specs., not sure I have ever seen anything on that part.

Neil.

i was talking about the cabin sensor with the fan didn't know there was any more sensors to this system, nut now i do. so i'll try to check this over the weekend

[dsno]

Found it for ya.... Jubel!!!



Heres the outside air temp specs, too - this one sits down in the climate system, inside the car, next to the fan.

thanks, much appreciated

[dsno]

i tested the cabintemp sensor today. and it seems to check out. unfortunatley its a bit hard to get accurat readings. but they seem to be within the tolerances.

where is the outsidetemp sensor located? ( i reckon this lives in the ducting somewhere?)

[scot850]

The outside air temp sensor is normally hidden in the small grille below the LH headlight. On my cars the sensor snaps into that grille from the back and can be accessed from below the front bumper.

I have posted pictures in the past on the location, but for the life of me I can't find the pictures on my computer to past again.

Neil.

[abscate]

I don't think the climate control uses that sensor for temp, I think it uses the one in the climate system just downstream of the fan. You reach it from under the dash. Expert correction needed please

[scot850]

I think you may be right abscate on reflection, the other one I mentioned is the one for the outside temp gauge. The one in the RHS of the lower grille intake is the engine outside temp gauge. Appreciate the correction.

Neil.

[dsno]

soo. i've finally got to measure the "duct" temp sensor. its the one behind the glovebox? see attachment.

however i cannot get this to corrolate with the chart that abscate posted.

at ~18-20c i get about 12.8k ohm across the the prongs.

i even had it at 14.4ohms at one time..


what gives? could this sensor be bad? the ECC didn't like being powered with the sensor disconnected. started to blink a steady red on the LEDs.

Dan