Trane XE 90-Blowing 5A fuse.

______________________________________________________________________ Need help in finding out what is blowing the 5 amp fuse on the ckt board. 1.The model is #TUX100C948C or XE90 DV. 2.Replaced the fuse. 3.I set the t-stat to call for heat. 3.Fuse blows when the door switch is engaged. 4.Started to take components out of the ckt, by disconnecting the wires. 5.Individually and replacing fuse after ea. attempt, I started with the draft motor, then the ignitor coil, and then the gas regulator. 6.I’ve checked the drop down x-former voltage-steady @ 27.2 VAC. 7.Red light on ckt board doesn’t come on at all. Any help would greatly be appreciated! Pat R. Replies: probertson “Re(1):Trane XE 90-Blowing 5A fuse.” , posted Mon 13 Sep 10:14 ______________________________________________________________________ Consider this closed. Swapped out the control board and unit is working fine. Asking around tho’, found other people that ran into the same problem. This was due to the grommet for draft motor condensate drain line allowing H2O to drip onto the board. Pat R. probertson “Re(1):Trane XE 90-Blowing 5A fuse.” , posted Fri 10 Sep 09:23 ______________________________________________________________________ No help with the jumpering of R & W (with T-stat set to “off”). I took off all of the safety control wires that were plugged into the control board, and installed a new fuse. This didn’t get me anywhere, the fuse still blew! So, I took the blower motor wires off the control board and again installed a new fuse, jumpered out R&W on the terminal block and a small capacitor on the control board (loc: near the fuse) burned up. I’ve since taken out the board and will get another, but my concern is-has it been the board all along or is the problem still in the furnace waiting for the new board? Please reply-Confused! Oh, the board is a White-Rogers (Intell-Igintion). Pat R. Mastertech “Re(2):Trane XE 90-Blowing 5A fuse.” , posted Fri 10 Sep 10:37 ______________________________________________________________________ Sounds like a board to me. The wires i wanted off are the control wires going to the T-stat and condenser unit. That will isolate problem to the furnace. At that time disconect safty wires and so on. But it does sound like the control board was bad. JDB “Re(1):Trane XE 90-Blowing 5A fuse.” , posted Thu 9 Sep 12:01 ______________________________________________________________________ You probally have a short in your low voltage wires somewhere. Trace the wires from the board on the furnace to the t-stat. If the wires look o.k. Take the t-stat off the wall and jump R to W. If it works, your t-stat if bad. HVAC4U