Foretravel Owners' Forum For owners and Fans of Foretravel Motorcoaches September 10, 2025 ...

2008 Phenix Dash air pressure switch

September 24, 2024, 11:11:39 am

I have a question about the hi/low A/C pressure switch. The compressor will mot engage for the dash air unless I jump 12 volts to the fan wire on the trinary pressure switch. Thought the pressure switch failed. I found the correct replacement switch. Replaced it and have the same problem. I can jump 12v to the 4th wire and compressor operates and dash blows cold air.
Does anyone know where that signal comes from?
Thank you.

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Re: 2008 Phenix Dash air pressure switch

Reply #1 – September 24, 2024, 11:58:00 am

You really need to have A/C gauges connected to the system to diagnose or you're just guessing. Jim.

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Re: 2008 Phenix Dash air pressure switch

Reply #2 – September 24, 2024, 12:58:09 pm

These may help ...

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Re: 2008 Phenix Dash air pressure switch

Reply #3 – September 24, 2024, 01:22:37 pm

Thank you for the reply.....The freon was recovered and reused. No schrader valve at the pressure switch. All the A/C pressures are correct and I can force the compressor on by jumping 12v to the 4th wire (added green jumper in picture) and cold air blows from dash vents.  I have been searching the forums and there may be a relay or breaker in between dash control to the pressure valve?

Steve, thank you for the drawings. On a quick look they did show a binary switch. It may lead me in the right direction. This system uses a trinary switch which FOT parts didn't have or were familiar with.

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Re: 2008 Phenix Dash air pressure switch

Reply #4 – September 24, 2024, 01:33:44 pm

Jeff, it looks like you have 2 relays there also. The first is triggered by the ac switch the other by the low pressure switch. Verify both of those are working. Jim.

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Re: 2008 Phenix Dash air pressure switch

Reply #5 – September 24, 2024, 03:53:24 pm

I can hear a relay in the dash for the ac switch. Haven't found it...yet. The dash fan is blowing Will need a 2nd person with more knowledge to trouble shoot much further.

Was hoping it was something simple. I will be at the Grand Vention and then the factory for service. If I can't get it fixed by or at the GV it's on the list.

Thank you.

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