Charging AC on 71 overlander

smily · 07-25-2002, 08:53 AM

I have 27' 1971 Overlander with overhead AC.

I notice that there is no Charging orfice on the unit. There is a copper tube (1/4 inch +-) that is crimped an soldered.

Any advice on the do's and dont's of charging this AC?

It gets cold but I would like it to get a little colder.

Thanks,
Ken

Pahaska · 07-25-2002, 09:53 AM

My son-in-law, who is in the air conditioning business, says that RV air conditioners very seldom need recharging. Automobile ACs have a lot of disconnects and flexible hoses and gradually lose charge, but, according to him, RV ACs have none of these leakage sources and ordinarily do not lose charge.

It may well be that it is doing all that it can do.

thenewkid64 · 07-25-2002, 10:29 AM

One of the other things to check is if the evaporator is clean. This would require removing the internal shroud and checking the fins with a flashlight. Your unit could be running cold, but the fins have gook on them not allowing for efficent thermal transfer. I am planning on performing this task this weekend, as mine has grey goop on the top 2-3 inches of the fins. This can cause the unit to freeze up as well. Yuo also may want to pull the outer shroud and check to be sure you have nothing like leaves blocking the condenser inside.

If your AC is an Armstrong and you pull the outer shroud be VERY careful. The shrouds cannot be purchased as they are no longer manufactured. This would also be a good time to check the drain and clean it as well.

smily · 07-25-2002, 12:24 PM

Thanks for the technical tip,

funny you should mention the shroud....
I am not certain what brand it is at this time but when I climbed up on topof the AS last week to check the AC, I found that the Acorn nuts on the shroud are very rusted and it will require cutting them off.

Any advice on removing these acorn nuts?
My concern is that whatever is below the shroud that the "bolts" are affixed to, how are they attached to the unit?

It seems that my unit puts off a lot of water from the AC unit. is this a good thing? I assume that this is due to good evaporation.

Seeing that the nuts are very rusted, I assume that the unit has not had a good house cleaning in a while. I will remove the shroud and perform the cleanig that you have recommended.

One other thing, my switch does not seem to have all of the positions indicated on the faceplate. My switch only rotates to the left and only has four positions although the faceplate has about eight positions, (low fan, high fan etc.). I suspect that the switch is not original equipment. to cool, the switch actually has to be in the far left position ,( about 11 oclock),which indicates "Heat ".

Do you know where I can get a OEM switch, or do I even need one?

As I mentined I am very technically capable with electricity and electronics but I know nothing about refrigeration. I have a neighbor that is a refrigeration type guy and he will assist me as long as I have some technical direction.

Thanks again,

Ken

Pahaska · 07-25-2002, 12:35 PM

If the unit is putting off a lot of water, then, the evaporator fins are very cold and/or the airflow is low.

My former house had humidity control on the AC; when the humidity was high, the controller slowed down the fan so that the evaporator got very cold and maximum water was removed from the air. Much water means there is either much cold or low airflow or both.

I would remove the shroud and check the evaporator fins for gunk. Also, the fan blades can get all gunked up if the filters were not kept fresh.

As to the acorn nuts, you might try heating them to try to break the bond.

smily · 07-25-2002, 01:52 PM

Thanks for the tip. My acorn nuts are much beyond breaking bonds though. I will have to cut them I am certain. I fear that applying heat may distort the shroud. I am looking forward to getting under there and seeing the state of the fins as suggested by my fellow AS'rs.

Maybe you can assist with the switch dilemma.

Thanks for the response,
Ken

74Argosy24MH · 07-25-2002, 06:28 PM

If it is an acorn nut, it has to be on a stud. I would try and cut the nut off, leave the stud intact. There is not much metal in there to weld a new stud to.

John

thenewkid64 · 07-25-2002, 06:33 PM

Cutting the nut can be done with a dremel tool and a cutting wheel. Just cut down the center of the nut and once you get thru to the bolt you should be able to finish splitting it with a screwdriver. I would reccomend using a wet old towel with a hole cut in it to protect the shroud from a runaway dremel tool as well.

What type of AC unit are you trying to work on? I am curious about your switch situation.