I have a Achiever 90 Plus RUUD Furnace. Model: UGRA-10EZAJS. what draft induction blower can I put on it

The variable speed DC motors you describe do use less power but cost 14 times more too, not worth it especially with you motor running!

see if voltage to gas valve if ok bad valve

Per Rudd's website and also as the name implies, the min rating is 90. The 90+ can be as high as 93 but is stated as "plus" to cover the many possible installation scenarios which will impact overall efficiency of the unit.

Its not the same but the manufacturer should honor the warranty if you are the registered owner

Check for condensation buildup in the Induction Blower housing. The condensate tubes or canister may be blocked and causing the diaphragm switch to trip the unit out causing the burners to shut down.

NO BECAUSE THE BOARD IS TELLING THE FANS TO STARTARE THE CONTACTS FUSED TOGETHER OR STUCK IN THE CLOSED POSISTION CHECK THIS FIRST

the fuse that your refering to is on the control board indie of the furnace. shjould be a 3 amp. good luck.

does the furnace ignite?? your system may not have been lighting and has gone into ignition lockout count the codes of the led lights then remove panel led diagnostic codes are listed there.
if led codes indicate no problem verify capacitor is good and that mtr is getting 115 volts.

The door, you mean the metal cover on the front? if you have the door off and push the safety switch in with your hand everything works fine? I need more info here, but if what I said is right, then the "door" isn't making good contact with the switch.