12 volt compressors not turning on

[dliterski]

I have a 1998 CC Intrigue. I just replaced the air bags on my HWH leveling system. The 12 Volt compressors don't seem to turn on when the self leveling monitor detects a low air bag when parked and leveled.
The air bags air up great when the engine is running and levels the coach out.
I checked all the fuses and they seem fine. I do hear the solenoid click on and off when it's trying to add air from the 12 volt compressors.
Any help would be appreciated....

[pogoil]

I have a 120 volt Thomas compressor for the air system. It starts and runs to build air for the leveling system. It fails to start if their is air already in the tank, I am trying to figure that out. I also have a 12 volt compressor in the front bay under driver seat, not sure what it is for. 1998 Concept.

[deandec]

My rig only has one 12v Thomas compressor in the front driver side bay (in addition to the engine mounted main compressor).

I do not know what out of level situation triggers the compressor to start to level the rig.

Never had an non-operational situation in almost 21 years. Knock on Wood.

When the engine is not running and I press the HWH leveling button twice to activate leveling, my 12v compressor starts to level the rig. The leveling result is very slow because that is a tiny compressor trying to fill big air bags.

Does your 12v compressor start working when you do the above sequence?

If not, you may have an electric supply or compressor problem.

If it does but no leveling results, you may have an air leak or compressor problem.

[davzcarz]

I have the 120V Thomas compressor in my coach and it has trouble starting after being run. I think the start capacitor is bad and needs to be replaced.

The compressor is in a compartment in front of the front basement bay along with the batteries (house and start) and the inverters. Pretty much impossible to get to the capacitor location without removing the whole compressor. I plan on replacing it with a 12 volt unit and moving it to the compartment under the drivers seat.
Thinking I'll use this:
https://www.amazon.com/dp/B000X9LTXA...v_ov_lig_dp_it

There is a small 12v compressor looking unit in the compartment under the driver but that is actually a vacuum pump for the dash air.

[gpounder]

Originally Posted by davzcarz

I have the 120V Thomas compressor in my coach and it has trouble starting after being run. I think the start capacitor is bad and needs to be replaced.

The compressor is in a compartment in front of the front basement bay along with the batteries (house and start) and the inverters. Pretty much impossible to get to the capacitor location without removing the whole compressor. I plan on replacing it with a 12 volt unit and moving it to the compartment under the drivers seat.
Thinking I'll use this:
https://www.amazon.com/dp/B000X9LTXA...v_ov_lig_dp_it

There is a small 12v compressor looking unit in the compartment under the driver but that is actually a vacuum pump for the dash air.

I could be wrong but the motor runs on 12 volts DC and would not have a starting capacitor.

[davzcarz]

My compressor is definitely a 120 volt AC unit and it runs off one of the inverters. When it tries to start and can't (locked) the amp draw goes way up and will trip breakers if I don't shut it off. I used the model number to look up the manual and a parts list online. I could not cross reference the start capacitor and they did not give any rating information for it. So my thought was just to pull it out to get the values off of it. As I said pretty much impossible to do with the compressor installed and I realized its not worth pulling it out and reinstalling it when I plan to replace it anyway.
I think it makes more sense to have a 12 volt compressor especially if I am levelling or using it when not connected to AC power. It seems like an unnecessary load on one of the inverters.

- David

[twinboat]

Right about where I circled should be a check valve with a line to pressure switch and unloader valve.

If either one is acting up, the compressor is starting against pressure in the tank. The unloader let's it start easier.

Test them by draining the tank and see if the motor still draws high amps.
Attachment 347114

[CountryFit]

Originally Posted by gpounder

I could be wrong but the motor runs on 12 volts DC and would not have a starting capacitor.

Not sure all of the CC models are the same, my Intrigue runs a 12v DC compressor for that.

[pogoil]

Originally Posted by twinboat

Right about where I circled should be a check valve with a line to pressure switch and unloader valve.

If either one is acting up, the compressor is starting against pressure in the tank. The unloader let's it start easier.

Test them by draining the tank and see if the motor still draws high amps.
Attachment 347114

The attachment did not show the picture. I have that same Thomas comp. It works great as long as there is little air in the tank then it also does the high amp draw and will make my inverter need to be reset. I have 2 inverters in my 1998 Concept. When I drain the tank or open the valve it starts right up.

[twinboat]

Trying again.

When the compressor shuts down, you should hear some air blow off at the pressure switch.
It's letting the air out of the line between the compressor and tank, so the compressor isn't pumping against tank pressure when it starts..

[davzcarz]

Thanks twinboat, that makes perfect sense and more sense than the start capacitor. I'll have a look later this week and post what I find.
Do you think the check valve just needs a cleaning or is it an easily to replace part?

Thanks,
David

[pogoil]

Is that check valve you circled under that fitting? I will undo mine and check/clean it.

[twinboat]

I think you need to look at the unloader valve near the electric pressure switch. It should hiss for a second just like your air dryer.