T870 Air Conditioning Control Panel R&R

[TobinG]

I have a 2017 T870 The AC is intermittent. I've changed the cab air filters and cleaned the filter behind the seat. Fan works fine, heat works, but the AC is a sometimes thing. It's been suggested that the control panel, i.e. fan selector, AC on off rocker and temp dial may be the issue.

Anyone have experience Removing and reinstalling this ~2"x 6" panel? I was hoping it would pop off without having to tear the interior out completely, but I don't want to break anything.

Any help appreciated.

Tobin

 

[fortworth-cowboy]

I have a 2017 T870 The AC is intermittent. I've changed the cab air filters and cleaned the filter behind the seat. Fan works fine, heat works, but the AC is a sometimes thing. It's been suggested that the control panel, i.e. fan selector, AC on off rocker and temp dial may be the issue.

Anyone have experience Removing and reinstalling this ~2"x 6" panel? I was hoping it would pop off without having to tear the interior out completely, but I don't want to break anything.

Any help appreciated.

Tobin

The A/C Control Panel pops just out, there are Taps on each side. Use a clip removal Tool or smaller flat head screw driver and it should come right out.
What exactly is the issue? When you run the machine, A/C running Engine running, look on the RH side of the machine, between the Cab and the Frame. You should see a Red light, is it blinking or is it solid on? That's the De-Icing Thermostat which controls the A/C Compressor. If its blinking, look how many time it blinks, like 1-2 or 3 times. If its Solid, that's normal condition.
If that Thermostat is not shutting off the Compressor, most likely your Evaporator will freeze up.
Let me know what you find.

 

[SkidTracks]

I have a 2017 T870 The AC is intermittent. I've changed the cab air filters and cleaned the filter behind the seat. Fan works fine, heat works, but the AC is a sometimes thing. It's been suggested that the control panel, i.e. fan selector, AC on off rocker and temp dial may be the issue.

Anyone have experience Removing and reinstalling this ~2"x 6" panel? I was hoping it would pop off without having to tear the interior out completely, but I don't want to break anything.

Any help appreciated.

Tobin

I believe you can rule out Fan switch, since you say fan works fine and heat works. You should feel air coming out of vents, even though A/C isn't working. Exception would be evaporator coils freezing up (coils below cab), resulting in air being blocked.

On a hot day, with A/C fan on High, Temperature cranked to Coldest setting, Cab door and windows open, the A/C compressor should be on almost continuously (compressor's hub is turning with drive pulley - compressor clutch engaged).

If compress's hub isn't turning most of time:

There is possibility A/C is low on charge (compressor starving for Freon). Which would indicate a Freon leak. On my T870, it took fluorescing dye in A/C system and parking machine in a deep shaded area to see dye at compressor's hub. Dealer's service team missed leak because of bright shop lights.

Along with possibility of intermittent wire/connection going to compressor's clutch which engages hub to be turn by drive pulley. Normally such an intermittent connection is seen when machine is being used (going over bumps); not while parked - idling.

 

[TobinG]

The A/C Control Panel pops just out, there are Taps on each side. Use a clip removal Tool or smaller flat head screw driver and it should come right out.
What exactly is the issue? When you run the machine, A/C running Engine running, look on the RH side of the machine, between the Cab and the Frame. You should see a Red light, is it blinking or is it solid on? That's the De-Icing Thermostat which controls the A/C Compressor. If its blinking, look how many time it blinks, like 1-2 or 3 times. If its Solid, that's normal condition.
If that Thermostat is not shutting off the Compressor, most likely your Evaporator will freeze up.
Let me know what you find.

Bingo!. You were spot on target. I removed and tested the control panel. All good. For future reference the toggle is an OTTO switch. Available from Digikey if you need on, but mine was ok. The temp control is a 10K pot with a 82K 1/2 watt wired to the center (wiper). Mine was all ok. As you specualted it was the deicing thermostat & control module. $125 delivered, 20 minutes to replace. Cold air! Many thanks!
Tobin