GM told Edmunds there are 42 fires linked to the recall and three minor burns, but no crashes or fatalities.
"In certain vehicles, the connector module that controls the blower motor speed in the heat/vent/air-conditioning system may overheat under extended periods of operation at high and medium-high speeds," GM said. "The heat could melt the plastic surrounding the connector module, increasing the risk of a fire."
GM dealers will replace the affected portion of the connector and harness.
This is part of a larger global recall of 196,379 Hummers.
A date has not been specified for the recall. Owners can contact GM/Hummer customer service at 1-866-486-6376.
No information about the recall has been posted on the Web site of the National Highway Traffic Safety Administration, which oversees vehicle safety in the U.S.
Edmunds says: Owners of these vehicles will want to stay in touch with their local dealer and address this problem as soon as possible. Formal recall notices are expected to be mailed within 60 days.