2003 V70 A/C Freezes Up. Evap temp sensor 30665118

[chrism]

Does anyone know what the expected temp vs resistance curve should look like for a properly functioning sensor? I can't find any data on the web.

I pulled out the evaporator temp sensor and measured the resistance:

Garage Temp (80 deg?) = 1400 ohms
77 deg = 1500 ohms
65 deg = 1700 ohms
43 deg = 2200 ohms
Freezer Temp (28 deg?) = 2200 ohms

It seems to flatten at 2200 ohms for anything below 43 deg. That concerns me because, it seems to me, it's that critical range between 43 and 32 deg that I would want to see a more measurable delta in resistance so that it would trigger a "Compressor Shutoff" command as it approached 32. Am I thinking right?

"...Low refrigerant on P2's shows for a long time as different temps on the different vents due to evaporator not being chilled over its entire surface..."

Come to think of it, I had that situation a couple years ago and yes, low charge was causing one side to blow cold and one side warm. But this time they both blow cold - TOO cold apparently.

[jimmy57]

freezing is 10K ohms +/- 200 and 25C/77F is 3K ohms range are the two I remember.

Your sensor is bad so CCM never sees the temp input to switch off compressor request.

[chrism]

Thanks, Jimmy. I'll order a new one.

[MoVolvos]

2003 V70 Base, 2.4 N/A 200,000 miles.

I’ve got an issue with my A/C wanting to ice up. For one thing I don't think the compressor is cycling off.

My little experience have been with R12 and 502. Since the compressor is not cycling off it should not be low on refrigerant. Low refrigerant will create ice build up on commercial and home reefers but the Compressor will be short cycling.

Blessing,
BKM
_

[chrism]

Just to follow up, I put a new evaporator temp sensor in Sat morning. I had loaned my ohm meter to a friend so I couldn't compare resistance between the old and new sensor. But during a test drive it did seem the compressor was cycling. Regardless of whether Recycle was selected or not, and regardless of how cold I set the temp selectors, I couldn't get it to ice up. Although the real rest comes with a nice looooong drive, I'm cautiously optimistic.

Now to get that PCV vacuum issue straightened out and figure out why my W/S washer reservoir leaks all over the garage floor. Those new Hyundai's look nice.

[abscate]

Nice call, jimmy57

OP had the right answer in hand in 23 minutes....

[thorv70t5]

viewtopic.php?f=9&t=86426

[abscate]

Found this on alldata

Part number 30665118