my 1998 gmc jimmy has no floor heat but i have defrost and ven heat
the heat blows out the defrost when it should blow out floor vents only
Most likely a bad or disconnected vacuum hose to the defrost/floor selector in the heater ducting.
Check under hood for a broken or disconnected vacuum supply line.
shut all vents off so it comes out on floor
from what i am hearing a lot of is that it is either the accuator on the driver side to the right of the gas pedal or the baffle door itself is broken(costing a sh*t ton of money to fix have to remove the dash). there is a while plastic piece that has a tendency to break on the end of the accuator that goes into the box. some ppl use a bent coat hanger to push the baffle through the driver side floor vent to get it to move so you get floor heat, then disconnect the red and blue vaccume hoses off the accuator to prevent the baffle from moving. use a nail or tape to stop the vaccume leak . you should still have all you functions for the rest of your heat controls. just the floor and defroster wont switch back and forth. they will both work at the same time. this is the case for each the blazer, jimmy, sonoma, s10, zr2 1998 and up. if you still have your heat working on the floor id suggest that if you own one of these vehicals that you don't turn your defrosters onto full fefrost mode. just floor defrost. what happens is the accuator by the gas pedal when placed in full defrost mode places to much force on the white plastic piece and snaps it, or the piece that's just inside the box. if you put into floor / defrost mode the accuator works as intended.. its mostly a design flaw from gmc that was never made public. it was a volintary recall item
The year, make and model info would help. Also need to know if the blower motor is working, just not getting any heat, or not changing function between defrost, dash or floor vents.
The vaccum door near the gas pedal is broken or not receiving vaccum.
One is the Heat on/off and the other is the Defrost/Floor lever.
Your blend door is giving you trouble, it is not switching from defrost to heat or vent
Common heater damper door indexing problem. Our 2000 back up shop truck hot is cold and cold is hot on the controls. Expensive to fix and usually requires a trip to the dealer
Hi, It is not the blend door, that is for heat/cold changes. The mode door could be the problem, or stuck defrost door.
It can, but for safety call or check with the banned that you have