AC compressor won’t turn off

[boaterholic]

On my 420 DB the fwd ac compressor will continue running no matter what I select on the thermostat, including off. It ran long enough non stop that it completely iced over the evaporator and lines when I went to check on it. Only way to shut the compressor off is to trip breaker for that ac unit. Can anyone give ideas on what to check? It’s a Cruiseair SFX16/1-HV-RMT.
Thanks

 

[bbwhitejr]

The keypads are known to go bad. Swap it with the one in the salon and see if you can cut it off.

Bennett

 

[boaterholic]

The keypads are known to go bad. Swap it with the one in the salon and see if you can cut it off.

Bennett

Will do, thanks.

 

[boaterholic]

I exchanged the two thermostats and no change. Both thermostats appear to be working normal.
I connected a manifold to suction side to see the R22 pressure. It was a bit low I thought at around 20, so I added more freon. When the scale got to around 38-40, the air coming out of vent was cold at 56-57 degrees. As more freon went in, getting to near 50, the air temp at vent has stopped getting below 68. Also, the compressor did eventually start cycling on and off, but now it's short cycling and not running long enough to get cabin to temp set on thermostat. I had the temp set around 70 to keep the compressor running while filling the freon.

 

[bbwhitejr]

I had issues once on a 44DB salon unit. There is a high pressure switch near the coils. There are 2 wires going to the switch I think. They are spade type connections. Pull them off one at a time and replace. I had a Dometic tech on the phone with me then and the connections were just not tight enough. Solved my issue that I chased for a month. Might give that a try.

Bennett

 

[boaterholic]

I had issues once on a 44DB salon unit. There is a high pressure switch near the coils. There are 2 wires going to the switch I think. They are spade type connections. Pull them off one at a time and replace. I had a Dometic tech on the phone with me then and the connections were just not tight enough. Solved my issue that I chased for a month. Might give that a try.

Bennett

will try it, thanks

 

[boaterholic]

I had issues once on a 44DB salon unit. There is a high pressure switch near the coils. There are 2 wires going to the switch I think. They are spade type connections. Pull them off one at a time and replace. I had a Dometic tech on the phone with me then and the connections were just not tight enough. Solved my issue that I chased for a month. Might give that a try.

Bennett

Tried it but no luck.

 

[boaterholic]

may try calling Cruisair tech support Monday.

 

[bbwhitejr]

may try calling Cruisair tech support Monday.[/QUOTE

I had great response from them 3-4 years ago.

Bennett

 

[boaterholic]

Called tech support this past Monday. They told me to open the electrical box and pull the yellow wire off the triac power module. turn breaker back on. If the compressor still runs when thermostat selected off, its the triac that is bad. If it shuts off, control board bad. In my case compressor continued running. So I ordered new triac off Amazon, came in today and I swapped out. New triac has the AC running normal. Thanks Dometic tech support.
I've ordered another couple for spares since I have a second AC and still have a spare. They are $15 on Amazon so a cheap fix thankfully.
Thanks all who tried to help as well!

 

[carterchapman]

Called tech support this past Monday. They told me to open the electrical box and pull the yellow wire off the triac power module. turn breaker back on. If the compressor still runs when thermostat selected off, its the triac that is bad. If it shuts off, control board bad. In my case compressor continued running. So I ordered new triac off Amazon, came in today and I swapped out. New triac has the AC running normal. Thanks Dometic tech support.
I've ordered another couple for spares since I have a second AC and still have a spare. They are $15 on Amazon so a cheap fix thankfully.
Thanks all who tried to help as well!

Would you post the Dometic Tech support # and triac P/N for all please?

 

[dtfeld]

There 2 parts to this system.

The AC controller (this is the box directly connected to the AC unit) has a triac that controls the pump on/off. In a single AC system, this is the part you will need. Part looks like this.

On a system that has 2 AC units sharing a single pump (shown above) , you should have a pump replay panel. Both AC units will have the pump output wired back to this box. These use a trigger relay. Part looks like this.

 

[boaterholic]

Would you post the Dometic Tech support # and triac P/N for all please?

When I pulled the triac off and read the info on the side, it was Saner brand, Saner TG35F60. Cost was $15.92. Here is the Amazon link:
https://www.amazon.com/gp/product/B00B88BPG6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Actual Dometic part number given to me by tech support was 758000006. From what I saw online they were selling at around $40-50. I did try to get from local Dometic repair facility but didn't have so I looked at the part and saw the Sanrex info and ordered exact part number for lot less $$

Dometic Tech support was 954-973-2477 and go through the menu selection for refrigeration

 

[carterchapman]

When I pulled the triac off and read the info on the side, it was Saner brand, Saner TG35F60. Cost was $15.92. Here is the Amazon link:
https://www.amazon.com/gp/product/B00B88BPG6/ref=ppx_yo_dt_b_asin_title_o01_s00?ie=UTF8&psc=1

Actual Dometic part number given to me by tech support was 758000006. From what I saw online they were selling at around $40-50. I did try to get from local Dometic repair facility but didn't have so I looked at the part and saw the Sanrex info and ordered exact part number for lot less $$

Dometic Tech support was 954-973-2477 and go through the menu selection for refrigeration

'll
Thanks sir - you'll get a laugh out of this - got to the boat this afternoon and the bridge air compressor won't turn off!! Only with the CB. So I'll be using your info sooner than I thought!!

 

[boaterholic]

'll
Thanks sir - you'll get a laugh out of this - got to the boat this afternoon and the bridge air compressor won't turn off!! Only with the CB. So I'll be using your info sooner than I thought!!

that was only way for me to turn mine off - CB