In my 98 E350 6.8 it is under the dash.
you have to pull the dash off to change it
You take it to a AutoTech.
Inline in one heater hose underhood near the HVAC box (right hand side underhood.)
The 1992 Acura heater control relay switch can be found beneath the passenger side dashboard. The heater control relay switch will be a few inches above the kick plate.
OK the heater is not letting the heat into the cab of my truck-I think the switch that controls the deflection doors is broken what is my answer the best thing to do.
on the right side of the throttle body
remove the glove box and there are three relays one is for the control door
It can be several things including the cont valve,if it has one, stopped up heater core, or thermostat. Have it checked out and don't throw parts at it as this can be expensive.
it is located on the passenger side valve cover
its on the back of the valve cover.
typically in the valve cover.
In the middle of the valve cover nearest the firewall.
In the transmission in front of the modulator