98 V70: A/C Comp Thermal Switch?

[sleddriver]

Home Weather Station Data:
Outdoor ambient: 99°F
Humidity: 43%
Solar Intensity: ~ 800W/M^2
Solar Heat Index: 122°F

Starting with cold engine, V70 outdoor temp gauge = 100°F
A/C ON, RECIRC ON, Fan Speed @ 75%

While driving, vent temp quickly dropped to 40°F. About a 15min. trip to HD, no change. Came back to car, V70 outdoor temp gauge = 113°F. Vent temp - 90°F upon start.

Drove about 10mi at 60MPH, made another stop for 10min with car off. Vent now 48°F. RECIRC still ON. Came back to car, V70 outdoor temp gauge = 106°F, vent temp = 80°F initially. Picked up two cans of 134a for $7/ea.

Light traffic on way home. At red light, V70 outdoor temp gauge = 100°F, vent temp = 46°F RECIRC ON. At next red light, vent temp = 45°F.

At home. Left engine on. Raised hood. Increased engine speed to 1500 RPM per above. Condensor temp = 150°F. Vent air = 60°F with RECIRC OFF. 45°F with RECIRC ON (after 6 min.)

Full can of 134a weighs 438g. Full can + tap & hose weighs 625g. Light sweating on suction line. Opened 134a can tap for about 3 min. Can quickly cooled. Turned sideways periodically then vertically. Can never ice cold. Turned off tap. Now can + tap/hose weighs 450g. Therefore 625 - 450g = 175g of 134a added.

Engine off. Hood up to cool down (my usual procedure this time of year). I'll let system pressure equalize, then retest later.

Solar heat index not as high today as yesterday (~ 133°F) due to more haze & puffy clouds today.

[abscate]

With 45F delta I would not have touched that system!

[sleddriver]

With 45F delta I would not have touched that system!

It behaved better today than yesterday, but that leaves me suspicious. May be a weak compressor.

Next thing I'll do is clean the condensor coil. I've done this before using an alkaline detergent which dissolves dried on bugs that can block airflow. Also a good time to relocate the two horns BLOCKING the condersor! Down here that matters!

Past experience has shown it capable of blowing a bit under 40°F with RECIRC ON even in brutal heat, even in traffic.

May just be showing her age.......

[abscate]

I've got that one bookmarked in my maintenance thread

[sleddriver]

Update:
40°F ΔT appears to be about right. Given the age of the compressor, heat, etc. and & other factors. It cools better when moving at 50 MPH than stuck in traffic.

When I came home, I left the motor running, opened the hood, and misted the A/C condensor with a 1/2 ga. water spray from a pump-up-sprayer. In a few min. the vent T dropped from 52 to 44°F.

Last year I mentioned the idea of using the rear window spray to instead spray the A/C condensor & intercooler during hot, dry weather such as I'm having here. Wagons are already equiped. Not sure how much good it would do the intercooler, but dropping the vent T to the low 40's would be welcome here when stuck in traffic and low speed driving.

More reason to relocate both horns....

NOTE: The "recaptcha" monster is really rearing her ugly head.....I had to go through it THREE times here....