Does not cool or freeze. Main coolant line is hot from top of burn chamber to almost the fins on top outside of cooling unit and then coolant line is room temperature.

Weak cooling is a sign of poor heat (cooling) transfer.
* Check cooling fins for debris and dust. These are the fins/coil just outside of the compresser/fan. The fan should be blowing when in operation. There should be warm/hot air blowing through all sections of coils and fins. The fins should be clear and able to see through at least most of the fins. Check for smashed fins. You can carefully bend them back straight using a plastic fork or wood comb. (No Metal!)
* Check the fan (on compressor) if it's clear and not clogged with dust, dirt, or mud. This unit is usually exposed to the elements so it will get dirty as you travel. Make sure it runs without touching the frame. It should spin freely and very strong blowing power, not a weak spin that is easily stopped by a passing breeze.
* Check the inside (RV Cabin) fan and coils for the same problems; debris, dust, dirt, bent fins, broken or weak fan.
* Once all of the above is checked then start looking at the operation. Is the unit running all the time? Can you adjust the thermostat higher in temp to allow the AC unit to turn off. Is it turning off at the set temp? It should cycle off at the temp setting at least within 5 degrees. If you can't control it then have the thermostat checked and replaced. (this may be the cause of the unit failure, which caused other sections to go bad too. So fixing the other sections without replacing a bad thermostat will cause the replacement to go bad too.)
* Most of these single unit A/Cs are sealed (welded) shut closed systems with no way to lose refrigerant unless punctured at one of the coils. (like using an ice pick to chip out frozen evaporator coils) Or traveling along and having a rock hit the condenser. If so then the unit will lose refrigerant very quickly and you won't have any cooling at all. Just a hot heater blowing. Don't run it in this condition as it will burn out the compressor.
* If this is a split system with a refrigerant charging port then you need to have a CFR certified tech check the system. If low then there is a leak (abeit a tiny leak) which needs to be identified and sealed. System needs to be drained, repaired, PSI tested, drained, evacuate, recharged, and final test for leaks, proper operation. Recharging an untested system will only cause a loss of refrigerant and another recharge.
* Final, check your warranty first before performing any repairs. Have them service and check operation.
Aloha, ukeboy57

Refrigerant is low. May have a leak in a cooling line.

Clean the coil inside and outside. try putting it in a window on a shady side of the house. I worked on a outside unit wher it was 90degrees outside but 107 degrees where it was in a hot location, close to road on sunny side of house.

Hi,
if you were the person that changed the water pump and t'stat this will be more of a 'follow-on'
A word of warning and advice, if you are going to work on the cooling system when it is in operating range, ie hot! Wewar a long sleeved work shirt /coveralls, work gloves and eye protection. If a hose 'blow's" when you are in proximity to it, it will cause injury. if you are caught like that, wash the affected with cool water a.s.a.p. and for a minimum of 15 mins. One, the washing will remove any anti-freeze, (bad for the skin etc) Two, the cool water will reduce the temp and thus the damage to the outer and inner skin formation. Most important to cool the UNDERLYING skin, it will greatly reduce reaction and damage.
Ok, here we go. If you8 have an assistant it will save you some tiome. The engine is warmed up and is at operating temp. Briefly check the top rad hose between thermostat and rad. If it's hot to the touch, the T'stat has opened, if cool to the touch the T'stat has NOT opened. Re'check the T'stat installation.

All is well, rad top and bottom hose are hot, coolant is circulating. Find and follow the heater hose from engine to bulkhead. Sometimes there will be quite a few hoses sharing a common center. Again, check that the inlet hose to the bulkhead and the return line are hot to the touch. This equates to coolant circulating. if inlet is hot and outlet cool, then the coolant is not circulating correctly through the heater box / matrix.

Under the hood, find and trace the vacuum line (s) which run from the engine to the bulkhead and check for leaks, a broken connector or a split hose. The underhood temps cook vacuum lines fairly easily, making them brittle. No problems found? Obtain /rent a hand powered vacuum pump, disconnect the main vacuum feed to the bulkhead, (under hood), attach it to the hand powered vacuum pump and operate the pump. If you have an assistant, have them sit in the vehicle as you operate the pump, WITHOUT the engine running. They should be able to hear the flaps on the airbox open and close. if they cannot hear them operate, there may be a vacuum leak inside the dash from a damaged line T-piece etc. To double check, start the engine, and operate the vacuum hand pump. Ensuring that you have plugged the vacuum source on the engine otherwise you may have poor starting, and a lumpy erratic idle.

Have your assistant operate the heater controls whilst you operate the vacuum pump. If the air flaps operate with the vacuum which you supply, and the heater mode directs hot air to the interior of the vehicle, then you have narrowed the problem down to a faulty vacuum feed at the engine supply.

Anti=Freeze enables the boiling point of the coolant system to be raised, and of course, depending on the mix, prevents the coolant from freezing at low temps. Do not mix the Anti-Freeze more than 50% Glycol and 50% water. Odd thing about anti-freeze, if you increase the glycol content, the engine will start to operate at a higher temp, with the usual problems which come with that situation. Certain Anti-Freeze mixtures have additive's included which are kinder to cooling systems which have a high aluminium content. In any case, after two years continous useage, Anti-Freeze properties start to decline and the coolant system requires draining /re-filling with new Anti-Freeze.

Hope that info is of some help.

The small line coming in from the outside unit should be warm to hot and the larger line should be cool and sweating with water forming on it. I am taking for granted that the unit was working if so it sounds as if the unit is low on freon. your inside coil should be sweating a lot from top to bottom if it is only cool or sweating on the bottom but less to nothing up top you are low on freon. When very low the unit will stop working just like a broken valve in the compressor. If it is just a little low it will not cool properly and at night it might even freeze the inside coil up.

Expedition and Navigator



Fig. 7 Remove the A/C plenum demister screw and remove the A/C plenum demister adapter



Fig. 8 Disconnect the vacuum line



Fig. 9 Remove the heater core bracket



Fig. 10 Remove the 13 retaining screws and remove the plenum chamber top



Fig. 11 Remove the heater core

1. Disconnect the battery ground cable.
2. Drain and recycle the engine coolant.

CAUTION Never open, service or drain the radiator or cooling system when hot; serious burns can occur from the steam and hot coolant. Also, when draining engine coolant, keep in mind that cats and dogs are attracted to ethylene glycol antifreeze and could drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantities. Always drain coolant into a sealable container. Coolant should be reused unless it is contaminated or is several years old.

1. Remove the instrument panel. Refer to .
2. If equipped with the 5.4L 4V engine, remove the junction block splash shield.
3. If equipped with the 5.4L 4V engine, remove the bolts and disconnect the cable ends from the starter relay.
4. If equipped with the 5.4L 4V engine, remove the junction block bracket.
5. Disconnect the heater core hose couplings.
6. Remove the retaining screw and remove the A/C plenum demister adapter.
7. Disconnect the vacuum line from the A/C plenum demister adapter.
8. Remove the heater core bracket.
9. Remove the 13 plenum chamber top retaining screws.
10. Remove the plenum chamber top.
11. Remove the blend door assembly from the case.
12. Remove the heater core.To install:
13. The installation is the reverse of the removal.

Also this VIDEO can help to solve your problem...

Hope this help.

It sounds like it needs to be charged. What you need to do is shut the system down for 24 hours in order to let the unit thaw. Then if you are not EPA certified, you need to have a repair tech come out and charge your system. That should be it unless you have a leak in the lines.

there is another fan at the bottom, rear, of the refigerator. remove the bootom panel and look at the cooling fins to make sure they are not bent into the fan blades. Caefully bend the fins away from the fan. this should improve the cooling of the refrigerator and get rid of the hot spot on the rail between the refrigerator and freezer.

Yes, if the filters are clean, the coils are clean, and it is still freezing up in cooling mode, then it is low on refridgerant.

this sounds like a compressor problem. if the outside coils are getting hot (and properly ventilated) but the inside of the unit is not getting cold then the heat is coming from the compressor.