Heater in the cab of my rv not heating - 1996 Ford F150 Regular Cab

cab heater? there are 3 fans, engine,cab heat and A/C. so....
a stuck CAB switch is a bad switch. easy huh?
if the switch only works on high but does move, that is a bad heater fan Resistor block. (usually bolted to fan hosing as it is air cooled this part)

hot air not being directed to vents? Check vaccuume hose under hood

HVAC? the cab heater is dead or weak.?
1: does fan blow?
2; is heater lever to max.?
3: is mode lever at heat?
4: does engine reach and hold at 180F or more? no guess, this really is the first thing, (mechanics) that must work first.

no engine heat , gives you no cab heat. ever.

are you handy ,or just want wild guessing
if handy ,all ways it can fail are here.
the system is simple, its only a heat exhanger.
but is complex do to modes.
here is the list
a mech, knows its 3 reasons (pure physics)
1: engine not hot.
2: coolant not flowing in cab rad core.
3: air not flowing through cab core.
just 3 possible, in physics.

the tests are simple.
http://www.fixkick.com/AirCond/heater.html

say what dont work.
ok the blower blows, and for sure on high.
so what do you want , and where.
heat to cab?
cold air conditioning to cab?
does not work, ok
lets do 1. no heat to cab,
blow fuse is 1st . check all fuse. (see glove box operators guide)
if no heat:
check engine heat, is it 180F and holding
check cap heater core hose, in heat mode are both hot. ?
if both are hot you have heat to the core and is a damper failure
in the heater box (or controller)


this car is a frankencar.
Honda Passport was a badge engineered version of the Isuzu Rodeo released in 1993 and sold by Honda in the United States

well either your heater core lines are clogged ore the heater core is just bad

Try this trick take the hoses off the heater core and flush it out with a water hose to get the airout the heater core.don't do it with the car running.goodluck

It's a definite possibility. Make sure your coolant level is good. Is the engine temperature coming up on your temperature gauge? If the engine temp is low and there is no heat in the cab, it's most likely a thermostat stuck open. If your engine temperature is good, but no heat in the cab, then it's probably something else like a plugged heater core, kinked hose to the heater core, or even your heat selector switch not working properly.

It doesn't sound like hot water is circulating thru the heater core. That model should have a valve on the intake hose that goes thru the firewall. Check to see that the cable is connected and the valve is working. If it is working properly, the hose should become hot on the heater core side of the valve.

if the inlet and outlet hoses are getting hot to the heater core then the problem is the air temperture control blend door actuator in the heating/A/C ducts, this door directs air flow either across the heater core or the AC evaporator or mixes the 2 air flows for a desired temp at the outlets, hence the name blend door, to change this part u must remove the dash assembly.

therostat stuck , or add anti freeze to reservoir if low