It means that when it only worked on high, that the resistor in the blower fan wiring went bad and the only speed the fan would run on would be a speed where NO resistor was being used, which is the high setting. Your fan went bad because it WAS only running on high for so long and now the entire assembly needs replaced. It's a PITA to get to because it's up in the dashboard so while you're in there, change out your heater core and wipe everything clean.
you are low on coolent, the heater core is the highest point and therefore full of air and not fluid
If you look under the passenger side dashboard you will find the heater motor ,attached to the motor is a fuse,check to see if the fuse is connected , or just replace the fuse , it worked for me.
A heater bypass is not an original equipment item. you would install it to keep coolant from circulating through the heater core, mostly when it is leaking.
replace the heater temperature switch
check the fuse or the ground on the heater
81
First, check your rad level, possible heater core plugged, vent door problem, feel the hoses at the firewall where the heater core is, if they both feel hot it is not hte heater core, rev up the engine to 3,000 rpm... if it heats up it could be a bad water pump!
They are Economists.
Michelangelo
you need to have a professional check your "freon" or R-134 refrigerant levels answer dont waste time getting freon level checked, freon is for air conditioning heat does not come from freon check you heater core. it is more than likely clogged up
So far no ideas are posted for this game plus Midway doesnt exist anymore.
have you checked the engine thermostat. I have a similar problem..no heat or air. according to a service manual there is a door at the heater core that is supposed to open when the heater switch is turned on. this could be the cause for both of our problems. any ideas for getting to the heater core?