The AC/heater (HVAC) system may unexpectedly switch to the defrost mode when accelerating. This system is operated by engine vacuum and should be inspected for any vacuum leaks if this problem develops. There is also a revised vacuum check valve available to address this concern.
Car problem reports
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Newest reported 1991 Dodge Ram Wagon B250 problems
The blower motor may operate erratically and the blower switch operation has a sticky or mushy feeling, the detents almost non existent. Our technicians tell us that the blower switch should be removed and inspected for overheating. This is common if the blower motor is frequently operated on high speed as the current flow through the switch tends to melt internal the components. Also carefully inspect all of the switch connector terminals for discoloration due to overheating and replace as required. A poor electrical contact at the connector will also cause the switch to overheat.
The door glass may separate from the glass lift channel. Our technicians tell us a front door glass channel kit is available to repair the door glass. The repair involves removing the door glass from the vehicle.
A clogged or restricted transmission fluid cooler system can be the cause of reoccurring transmission failures. Our technicians tell us that if your transmission has failed due to lack of lubrication the transmission fluid cooler and lines should be thoroughly inspected for restrictions.
One the 3.9L V6 and 5.9L V8 the carbon buildup on the top of the piston is common. As the buildup increases with mileage and over time, symptoms may vary from light ticking, to ticking/hammering, to hammering/knocking noises. Fuel injector cleaner often solves the problem.