Rear Starcool AC only cool with engine on

Benjamin · 07-24-2022, 09:46 AM

Good day!
I have a 2000 E350/RB 50 with a Starcool rear AC built in Texas. I have owned it the last 10 years without issues with the AC other than a freon charge 6 years ago. However, over the weekend I took my 5 yo for his 1st camping trip in the SMB. I AC blew cold while on shore power. We went for a little drive and hooked back up to shore power and the rear AC wasn’t blowing cold. I noticed that my son switched the thermostat switch to heat (we have never touched this switch bc we live in SW Florida) and thought it would be an easy fix but still no cold air. When I turn the engine on the rear AC is very cold. I checked all the simple thing (fuses/switches) to no avail. Any thoughts or suggestions on what could be wrong or how to fix?
Thanks in advance! Ben

Scalf77 · 07-24-2022, 10:49 AM

being that it blows cold when you are driving and the fact your son played with the thermostat, the first thing I would check is that. It is not needed when the engine is running, that is only for when on shore power.

-greg

doublevan2 · 07-25-2022, 06:10 AM

Speaking of Star Cools - mine is running fine - but wondering where one buys spare parts these days - even if just a new thermostat ? Maybe buy one to have on board when traveling ? Parts sources anybody ?

BrianW · 07-25-2022, 08:09 AM

Thermostat is just a regular one that you can buy at Home Depot.

**daveb** · 07-27-2022, 06:40 AM

You should hear the 110 compressor cycle if you are on shore power, provided the switch on the thermostat is on cool and the temp slider is set to it's coldest setting. Sounds like maybe the thermostat switch or slider isn't working correctly. Can you hear the shore power compressor?

BTW If I drive with the thermostat set to cool and I turn on my inverter, the starcool thinks it's on shore power and will try to cycle. My inverter can't handle the load and will trip off. Probably has nothing to do with your problem though.

Scalf77 · 07-27-2022, 07:46 AM

Quote:

Originally Posted by daveb

BTW If I drive with the thermostat set to cool and I turn on my inverter, the starcool thinks it's on shore power and will try to cycle. My inverter can't handle the load and will trip off. Probably has nothing to do with your problem though.

Dave,
If this is happening then you have a wiring error or bad relay. One of the relays on the Startcool relay panel is there is to isolate the "110" system while the van is running. The 12 volt input on the input of the cool line of the thermostat comes from this relay. This is wired on the always on connection of the relay, so it could be bad or it is not receiving a 12 volt ignition on input.

The below diagram shows the light blue ignition input, which if picked should take 12 volts away from the thermostat.

For the original poster, you can measure the input to the thermostat(RC) at terminal 4 and the output (Y) at terminal 3.

-greg

**daveb** · 07-27-2022, 11:20 AM

Not sure Greg. This was told to me by SMB in 2006 when it happened not long after the van was built. However they completely replaced the whole system it around 2007 and I haven't tried to start the new system without shore power. I've just made sure the thermostat switch is in the off position (IIRC) when driving. Maybe I'll go out and check it when it cools off around here. I haven't used the 110 compressor for several years. Almost afraid to start it being it's so hot this time of year. The Starcool AC compressor was one of those things I have never used or really needed much.

vlagat · 08-01-2022, 10:15 AM

Are you sure the circuit breaker for the Starcool is on,; did you cycle it?

doublevan2 · 08-02-2022, 08:28 AM

daveb -- sorry for my lack of brain power - but what's - "iirc". in your post - junior member - still learning !?

Anybody else could chime in also --

marret · 08-02-2022, 08:38 AM

I'm sure daveb can answer for himself, but there are a number of online acronyms used, IIRC is one. Typically means "if I remember/recall correctly".