Cut Wire at Furnace

[George]

Please help me figure out if this a problem or not. The furnace works but I have found a cut wire from the thermostat.
At the furnace there is a pair of wires from the thermostat. Both of these RED and WHITE wires are crimped to the furnace BLUE wire. The WHITE wire has been cut, see attached photo.
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The t’stat wiring diagram labels the RED as +12VDC and the WHITE as FURNACE.
The furnace wiring diagram labels the BLUE wire as THERMOSTAT.
The furnace BLUE/WHITE wire is not connected to anything. Labeled POWER TO THERMOSTAT.
Should this WHITE wire be repaired?
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I might mention that all 3 butt splices were tucked into the squirrel cage and the -12VDC splice was worn through. The white wire may have been cut by the squirrel cage but it seems unlikely.
If you're wondering why I have the cover off – I'm painting it. Suburban's idea of weatherproof paint leaves something to be desired. Chalked up after <2 years.
I've also sent this to Alliance Service and will post any response from them as I receive it.

 

[George]

Update: Alliance contacted me and advised repairing the white wire. I did so and the furnace fires and shuts down as expected.
I replied that I am still confused as to why the RED *and* WHITE wires are both terminated to the furnace BLUE wire. I also asked where typically this 2-conductor cable is spliced into the 6-conductor from the thermostat – at the rooftop A/C?

 

[George]

Update to Update: 🙃
Alliance Service confirms that the 2-conductor cable picks up the white wire from the thermostat at the rooftop A/C unit.
I haven't climbed up there but I suppose they just used both the RED and WHITE for redundancy. This actually saved me from an inoperative furnace since the white wire was cut.
May I add that replies from Alliance were timely and appreciated.

 

[brytonmar]

I'm diagnosing a similar issue with my 2023 382RK. I found the white thermostat wire cut and it doesn't appear to have ever been connected with the red and blue and appeared to be taped off with masking tape. I also found the blue/white wire which is hot at 13.7V from the motherboard, cut and just sitting outside the hole to the left of the heater box. I have not been able to get the blower to come on since the thermostat was tested not working by a technician a couple of years ago. The new thermostat drives the air conditioner, but not the heater, suspecting it is one or both of the wires that is the problem. If I touch the blue/white wire to the blue/red thermostat wire, the blower comes on. Trying not to fry anything, does anyone have a suggestion where the wires need to be hooked up? I could hook the white wire to the red and blue like this thread suggests, but I have no guess where the blue/white wire needs to go.