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I’ve had this nightmare for a couple years. It never had heat. That’s ok for Florida but not so much MN.
I hooked it up a few weeks ago. Heater core leaked. Replaced it yesterday and after putting it back together it only blows cold through the defrost. At least it doesn’t leak. The blower is adjustable still but not the directional or blend. My guess is that’s where it is. What next? And please don’t say I have to remove the dash again. Thanks for any help.
Per your profile, assuming 2003 Ford Ranger V6~4.0L~SOHC? And freezing your **** off in MN without heat in the truck!
Your VacuumControlled HeaterControlValve has either 2HoseBarbs or 4HoseBarbs?
Check that it's cycling when you switch cab heat on\off.
And that the heater hoses going thru firewall are getting warm when the heat is on.
If its a 1995 and up then there can be a few issues of WHY there is no heat in the cab
After engine is warmed up check if BOTH heater hoses at the firewall are warm, that can tell you what to check next
If air only comes from Defrost vent then that's the same reason on all years, there is no vacuum present at the cab's vent selector switch
Defrost, Panel, Floor vents are all controlled by vacuum "motors", like a vacuum solenoid
Defrost is the default selection, i.e. no vacuum = defrost
If 1995 and up, in the engine bay, front passenger side down low, look under bumper, there is a Black plastic ball, thats the Vacuum Reservoir
There will be a black hard plastic vacuum line running from that unit to the firewall passenger side
These hard plastic lines "look like" wires
This black line runs into firewall and comes out under glove box in the corner of cab, picture here: https://www.explorerforum.com/forums...tch-jpg.77025/
Thats a picture if inertia switch but just above it are the TWO vacuum lines that come into the cab from the engine bay
Look in the engine bay and find the black plastic line, there is also a GREY plastic line, the 2nd vacuum line
The black one often gets melted by exhaust system or gets brittle and cracks, it can be repaired with regular rubber vacuum hose
It can also be the vacuum reservoir is cracked, but 99% of the time it the black plastic line that breaks so only Defrost in cab
And since you may have pulled out the dash then it could be a vacuum line got pulled out and just needs to be put back on
If both heater hoses get warm in engine bay at firewall then:
On 1995 and up most common issue for no heat in cab is failed Blend Door Actuator, its in the cab
Its an electric motor that moves a door that diverts the air flow THRU the heater core(HOT), or Around the heater core(COLD), its controlled by the dash TEMP ****
No control valve right now. Figured heat was the issue that needed fixing right
now. Could deal with blending later.
it never had a valve and the a/c always worked.
It was after I reassembled things yesterday that I no longer had directional controls. I have no clue about the blend controls as the hoses were always looped.
The truck never had heat. Or rather it was disconnected years before. It had a leaky heater core. A/C worked fine. Lines were disconnected and looped. I fear I did something when putting in the heater core. I did the job myself so there was a lot of back and forth to get the dash reassembled. I’m not a mechanic but I’m not and idiot and I’m wondering where I need to look.
ok I’m closer to an idiot.
Since you noted the heater hoses had been disconnected\removed by a previous owner,
a 5/8"ID CoolantHose should run from the ThermoStatHousing top right to the HeaterCore inlet,
a 5/8"ID CoolantHose should run from the HeaterCore outlet to the HeaterControlValve,
a 5/8"ID CoolantHose should run from the HeaterControlValve to the WaterPump right side inlet.
A small VacuumHose should run from the HeaterControlValve diaphragm thru the firewall to the dash controls.
Also, there was originally a PCV Warmer CoolantLoop that had smaller hoses parallel with the Heater hoses; they may or may not still be there?
Then you most likely pulled off a vacuum hose, check under glove box to see if BOTH hoses are connected
The valve in the engine bay was only used in MAX AC setting, its not a "heat control" per say, like on older vehicles, it stopped flow thru heater core when MAXIMUM COOLING was desired in cab
So that valve's default(broken) setting was flow thru the heater core, so heat in the cab was default
So...I never would have guessed this in my life but, things don’t work properly when you don’t plug them back in. Dropped the glove box and saw two connections I forgot to make. I knew the other day I had unplugged more than what I put back together but the glove box was closed and I didn’t look. Thank you so much for your help.
