Forgot more than I know

[tbirdtbird]

From initial post,
"24" fan on high blowing directly into the grill of the car"

May have condenser issue nonetheless.
When temps get hotter instead of the fan use a garden hose on the condenser to see what happens

[bevis]

new condenser last year but you never know

[bevis]

when I did the compressor / accumulator / condenser changeout last year
I dropped exactly 7oz of PAG 46 into the compressor

[Dougflas]

airflow across condenser

[bevis]

both fans kick in and run full tilt and then cycle off and on. when im using the 24" fan, they dont kick on until I run the rpm up for extended periods of time. the better or worse operation of the ac / vent temps are chasing around with the ambient. I may have it over charged . can I take a temp reading at the inlet of the evaporator and adjust the charge with that temp ?

[tbirdtbird]

The method you want to use to adjust the charge is unconventional, and I am not convinced the charge level is wrong.
Doug just followed me along with the idea of not enough airflow, and he knows lots more than I do.

We do a lot of custom work here, and we always make sure the condenser fan is on if the compressor is on, period. We will use a relay off the main on-off dash switch to run the condenser fan. No cycling for us.
We have also re-wired OEM systems to make sure the condenser fan is on at all times the compressor is on. The condenser function is absolutely critical to the system.

We have also replaced condenser fans that seemed to work OK but in reality they get tired and old and don't blow enough air anymore. Under these circumstances, the engine itself will typically not overheat but the AC function will be sub-optimal.

All of this is why I suggested misting the condenser with a hose, with the engine at 1800 rpm to see if the vent temp comes down.

You are accustomed to a residential condensing unit where the compressor and the fan both come on together and you never even give it a thought. Those 220V fans don't seem to get tired they just go out or the cap dies. You have changed out lots of condensing unit fans in your career, for sure.

[bevis]

that's pretty damn spot on !
I was trying to correlate why you wanted the condenser misted .
Now I know.
As far as the fans, I could use a 30 amp relay and tie the coil voltage for that relay
to the hot compressor wire and feed the fans from straight B+ voltage across that relay

[tbirdtbird]

Wonder what is controlling the fans now?

Imagine cycling the fan on a residential CU (Condensing unit)?

What is the gap between the condenser and the radiator?
Any trash, leaves, etc between the two?
Is there any way air can get around the condenser before it goes thru the radiator? You may need air dams around the perimeter
Are the fans tired?

Misting costs zero and can help a lot with diagnosis

[Dougflas]

Also make sure the fans are turning in the correct direction.

[bevis]

the car is in stock configuration and its a HUGE pain in the ass to change the condenser as its behind the radiator and comes out from the bottom. fun times.....thank God I have a 4 post lift. there are no missing air dams or air directing pieces missing.
The car has 139k on it and it has no litter or other obstructions in front of the radiator or the condenser.
I have no way of measuring the static pressure from these fans but they roar when on. that does not mean
that they are moving the correct amount of air though.

As far as oil in the evaporator, there's no way for me to know.
Im about ready to buy a 30lb cylinder of R11 and run the whole damn 30lbs through
the system and recharge the compressor with oil. I don't know how else I would get the oil out of the evap
short of tipping the car up on end and at an angle. I could pull the accumulator and see if theres a bunch of oil in it
but then id want to put a new one on it. next time I put the vacuum pump on it, its going to run all night before I
dump a charge in it. I thought that HVAC could be a pain in the ass...wrong. MVAC is worse than a heat pump