Roadtrek AC question 1999

[JeffGalan]

99D190P

Has anyone had any issues with their AC compressor not working in temps 105+?

I don’t mean NOT cooling enough, that’s a given being the temp is 105.

I mean when the hottest part of the day comes the compressor won’t come on till about 6p or so when it is cooler. Then it’s flawless all eve, all night, the morning.

I was going to replace it till I thought…

Maybe this design of the unit NOT fully on the outside but in a case with vents is contributing to this heat and failure.

So I’m thinking a new one would do the same.

So are you all able to operate your ac in 105+ temps?

Thx.

 

[TX-Trek]

The ac relay may have weakened over the years and susceptible to heat. A very easy and inexpensive check is to replace the relay. I've seen several relays over the years work fine at moderate temps, then fail at higher temps.
Not sure on dodge, I'm assuming that there's an underhood power center with various fuses and relays.
Also suggest to check the high and low side pressures in the system while operating.
This may be a bit more uncommon, but be sure the connector at the clutch is clean and in good shape.
Another check would be the inline pressure switch, usually a 2-wire open/close switch. They sometimes start to fail and cut the circuit. You can briefly jumper across the 2 leads only to see if the clutch engages, don't leave it in though.
These are generally the simplest initial checks.

 

[JeffGalan]

The ac relay may have weakened over the years and susceptible to heat. A very easy and inexpensive check is to replace the relay. I've seen several relays over the years work fine at moderate temps, then fail at higher temps.
Not sure on dodge, I'm assuming that there's an underhood power center with various fuses and relays.
Also suggest to check the high and low side pressures in the system while operating.
This may be a bit more uncommon, but be sure the connector at the clutch is clean and in good shape.
Another check would be the inline pressure switch, usually a 2-wire open/close switch. They sometimes start to fail and cut the circuit. You can briefly jumper across the 2 leads only to see if the clutch engages, don't leave it in though.
These are generally the simplest initial checks.

I don’t think it’s electrical. I unplugged it and plugged it into another power source and did the same thing.

On FB three of us that have the same LG 8000 BTU units experience the same thing so I guess it’s an LG thing.

It works flawlessly under 105 degrees.

Thank you for the input. Will likely just replace it as they are under $200 for a new one.

 

[TX-Trek]

Oh, I think I've misunderstood - I thought you meant the vehicle ac under the hood. When you mentioned LG 8000btu I see you meant the coach ac.
Apologies, my bad!

 

[JeffGalan]

Oh, I think I've misunderstood - I thought you meant the vehicle ac under the hood. When you mentioned LG 8000btu I see you meant the coach ac.
Apologies, my bad!

It’s quite all right. I appreciate anyone writing. I wish it were the cab ac. Seems easier to diagnose. Enjoy your weekend.

 

[TX-Trek]

Thanks and you too. I hope you get it solved, way too hot for intermittent ac.

 

[JeffGalan]

You’re welcome. For sure. Thx

 

[jjrbus]

Unfortunately this is not a lot that can be done with a window AC. I would start with cleaning the AC filter and inside and outside coils. I am guessing with dirty coils it is tripping the high temperature switch. I have seen perfectly good RV AC replaced because the coils were filthy!!! Coil cleaning videos on You Tube. I would try spraying water on it before trying to start to cool it down, just to see what happens. No I do not believe AC not working in hot weather is normal. If you do replace add a hard start capacitor to the new one.

With 100 degree + everyone may be turning on their AC and you are experiencing low voltage, measure your voltage to see if it might be the problem.

 

[JeffGalan]

Yea true. Not much to do with these but replacing them. I have cleaned the coils front and back many times. I do spray water on the condenser and mist a bit on the evaporator by spraying the filter lightly to bring in cooler air. I guess it seems to help it. 3 other RT people on FB with the same unit have the same identical issue. I raised the question if this RT design of it being not fully outside being an issue with extra heat inside the case or whatever is called where the ac sits. I’ll have to get someone to do the capacitor thing as I’m awful with those things. Thank you for the input.

 

[jjrbus]

Yea true. Not much to do with these but replacing them. I have cleaned the coils front and back many times. I do spray water on the condenser and mist a bit on the evaporator by spraying the filter lightly to bring in cooler air. I guess it seems to help it. 3 other RT people on FB with the same unit have the same identical issue. I raised the question if this RT design of it being not fully outside being an issue with extra heat inside the case or whatever is called where the ac sits. I’ll have to get someone to do the capacitor thing as I’m awful with those things. Thank you for the input.

I am still thinking low voltage or brown out conditions during the heat of the day, in which case I do not think a new AC will help. If it were me I would buy AC from someplace with easy returns and test before installing. Test on weekday when electrical demand is usually at it highest.

 

[GroupB]

Yea true. Not much to do with these but replacing them. I have cleaned the coils front and back many times. I do spray water on the condenser and mist a bit on the evaporator by spraying the filter lightly to bring in cooler air. I guess it seems to help it. 3 other RT people on FB with the same unit have the same identical issue. I raised the question if this RT design of it being not fully outside being an issue with extra heat inside the case or whatever is called where the ac sits. I’ll have to get someone to do the capacitor thing as I’m awful with those things. Thank you for the input.

My speculation based on 4 identical performance problems is that the thermal shutoff on the compressor motor is tripping. Other than the ambient temperature or low voltage situation, the other thing that could be the cause is if the RT installed flow dividers that separate the incoming ambient air and the hot exhaust air, located behind the outdoor AC grill, are missing or damaged

 

[jjrbus]

My speculation based on 4 identical performance problems is that the thermal shutoff on the compressor motor is tripping. Other than the ambient temperature or low voltage situation, the other thing that could be the cause is if the RT installed flow dividers that separate the incoming ambient air and the hot exhaust air, located behind the outdoor AC grill, are missing or damaged

My best guess is if it was the dividers the issue would have shown up long ago. Let us know what the outcome is.

 

[wmgeorge]

From a HVAC guy, compressors are cooled in part by cool suction gas coming back to the compressor and in part by air flow. Unless you clean those condenser coils from the from both sides with a good flow of water and soap they are not clean. Flow water from the leaving side back to the entering air side. Window units need to have that motor covered in plastic so you don't get it wet. If at a certain point the cool suction gas coming back to the compressor gets warm the compressor will overheat and trip the internal overload. So to hot on the interior creates an overload as well as the outside air temperature. Long term, replace the entire unit with one with more Btu's.