skeeter0288

my 87 has hvac issues. the defroster has little coming from the vents, the vents out the front of the dash do not have much air coming out , and the floor vents do not have much coming out. dash controls work fine , blower motor works fine.i know the resistor is shot , there is no low speed . i am not sure where to start to look for duct problems. anyone out there have these issues? any help is appreciated.

millball

How do you know that the dash controls work just fine?? When I got my '87 none of the cables would move because the cable clamping arms on the back of the HVAC controls had been broken by someone who did'nt know how to properly remove the unit. Have you examined the cable connections at the heater plenum and verified correct movement of the air control doors at their various locations?
The dash controls move 4 different cables that open and close the various air doors and the hot air blend door and hot water valve.
If there are no problems with the air door positions, the only thing that remains is the issue of debris plugging the heater/and or the evaporator cores.

skeeter0288

when the controlsare moved you can hear the doors move and the air stops coming from one position and goes to another position- just very lttle air discharge. yes it is 27 yaers old but only has 128000 miles on it. i bought the truck from my aunbt and she told me it has been like that for years.

rworegon

Dirty heater core? Mouse nest in duct? Mouse nest inside fan? Air intake in cowl restricted by debris?

Terrys87

iTrader: (1)

Once you pull the glove box out, I have seen the short section of pipe marked "PE" pipe missing. If it is not missing, like mentioned, most likely there is alot of debri in the cowl and has dropped down to the blower motor and gotten over tot he heater core and AC Condenser. This https://www.yotatech.com/forums/f116...4-88-a-278925/ can show how to take the dash apart and to clean the pipe and ventilation system. Post 1-4 and some further down on the first page shows a few other things.

Also the blower resistor you are talking about. Pay attention to wether you have a 3 prong or 4 prong resistor. Toyota had 2 different styles and and they look the same.