I was doing a clean and check on a Carrier Model: 58CTA070-10108 2-stage 80% furnace. It lit on low fire just fine but noticed when it went to go to high fire the gas valve would open to 3.5" W.C. but it didn't sound like to blower motor ramped up. I checked the temp rise and sure enough it was 17 deg out of range. I checked the voltage at the high fire spade connection on the circuit board and found no voltage. I just found it strange that the gas valve opened up to high fire but the blower motor stayed at the same speed. This is the first 80% 2 stage Carrier furnace I have seen and just wanted to make sure I wasn't missing anything obvious. I am 95% sure it is a bad control board but the customer is a good friend of mine and I hate to tell him that the repair will cost him lots of money.
The board should shift to a higher speed on a timer. The fan relay is faulty and you need a new board. A 2 stage board can be quite a bit more expensive than a single stage but hopefully you can get in at wholesale price for him. If not try Americanhvacparts.com
"Cut it twice and it is still too short".