I guess every knows that the Inducer Fan Motor is giving him a problem right now and it needs to be replaced with a new OEM motor.
But that is not a complete repair. Again this unit has a major issue per the Trane Service Bulletin which specifically address a complete upgrade to prevent total malfunction of ALL the controls and related switches and contactors.
Its not a big deal but if the upgrade has not been performed it is certain that he will have major problems with the remaining controls when the motor fails. There are no safety's in place which will prevent this failure and its highly possible that a fire can develop with in the controls cabinet.
So.....The kit is available which is to alter the existing control sequence of the inducer fan motor. It includes wire harness and isolation contactor for HI and LO speeds.
To understand it better he will have to read the service bulletin. I have one somewhere but for now here is the repair kit Lit No. which he needs to get for the repair.
The Combustion Fan Motor Lit: RT-SVN17A-EN Dated February 20011
Troubleshooting is not part of the repair...understand the symptoms and you will find a solution.