The pressures are a bit high... I know you converted to e-fans, but have you tried adding a small pusher fan directly on the condenser that is activated by the A/C switch? I have done this to many vehicles in the southwest to improve upon their A/C performance. Not enough to block a majority of the surface, just a little one up on the top corner where the charge initially enters to speed the cooling process.
I do believe you have other issues, though.
Another crazy idea I have floated in troubled R12 conversions is to add a second condenser in front of the first... plumbed into the rear one first, then out of the rear and into the front one, then out to the accumulator/dryer. Only requires some simple spacer fab and longer bolts, with the addition of one custom high pressure hose between the two units. This would add a shit-ton of capacity to the system, while cooling the refrigerant back close to ambient before entry into the orifice tube.
Not a bad idea. Would have a ton of capacity when in slow traffic. Plumb it to the front condenser first.
What engine rpm are you taking your temp and pressure readings at?
ideally 1200-1500 rpm.
And you are trying to cool a big cabin, but any AC system should put out vent temps 30 degrees below ambient. From the factory they were designed to only be 20 degrees below ambient.
--12 years working in a Ford HVAC lab testing all the Ford HVAC parts as well as competitor's parts.
40-50psig is too high.
If you have an orifice tube, you have an accumulator,not a dryer, similar but they work differently. The pressure cutoff switch should be mounted on the accumulator. Under the plug there is a slotted screw head. This is the cutoff adjustment. (if there is no screw head, you have a newer model is non-adjustable- these suck) Using your pressure gauge, raise the rpm to 1200 or so and adjust the cutoff for about 30 to 32psig. This will do wonders. 28psig will hang icicles and freeze the evap on a humid evening. Been there.
--12 years working in a Ford HVAC lab testing all the Ford HVAC parts as well as competitor's parts.
You really got my interest now. Before I play with this I would like to understand what I'm doing.
First, I do have an orifice tube and I did miss name the accumulator. The accumulator does have a cut off switch and I pulled the plug and it does have a slot screw under it. So far so good.
Now what I don't get is the orifice tube is before the evaporator, but the low side service port is in between the evaporator and the accumulator. So how is adjusting something after the service port going to change the pressure. (Unless the accumulator is a restriction) When you adjust this, are you adjusting the cut off? That doesn't seem possible. When you say adjust it to 30 psi., I have to ask, doesn't the compressor shut down when this is unplugged? Do I adjust it a little and then plug it in to check what I did?
I guess the main question I'm asking is what does this screw do?
Cool, You guys really fucked up with the eatc system on the panther chasis. Your blend doors suck balls.
Tiha, I blew up a lot of parts to make things better. A few not in a fun way.
If your compressor is cycling with AC on max, meaning it is tripping the low pressure cutout, then that means you are still not fully charged. That would make your pressures even higher when done.r.
has the insulation on the line feeding the evaporator gone away?