J Jason R Guest Jan 22, 2009 #1 ...defrost when going up a hill? what will cause this and how do i fix it
M Mike V Guest Jan 22, 2009 #2 the heater controls are vacuum operated. you have a vacuum reserve canister to make up for a loss of vacuum. i suspect that it is malfunctioning and causing your problems. most heaters will default to defrost when they have a control system problem
the heater controls are vacuum operated. you have a vacuum reserve canister to make up for a loss of vacuum. i suspect that it is malfunctioning and causing your problems. most heaters will default to defrost when they have a control system problem
