heater problems

item 16 should have vacuum going to it whenever a/c is on that shuts off water flow its' under hood.

The heater only blows cold air, thermostat is new, the control valve, that allow hot water to heater core is ok (both upper and lower) lines from heater core ,inside engine comparment are hot to the touch, but no hot air coming from vents

Are both heater core hoses the same temp?
Are they (both or just one) hot or just warm? Can you feel air from all vent positions, dash, defroster and floor?

this guide can help us

https://www.2carpros.com/articles/car-heater-not-working

Please run down this guide and report back.

Yes to all the questions

Is your fresh air door open?
If it is open, not on recirulate and both heater hoses at the heater core are hot, then i would recheck and make sure the control valve is opening al the way allowing the hot water through the heater core.

98 Ranger-heater problem-heater will get hot when first started then cool down when driving-have had system flushed twice-replaced blend door-replaced thermostat, coolant control valve, water pump, clutch fan. When you take the hose loose to the core for any reason then replace it, the heater will get so hot it burns your hand-then after driving apxy 6 miles it starts to cool down. Is it possible the core has something in it that is blocking the coolant flow after it gets hot? I'm about to run out of options. tks

Did you put in a 195 degree tstat? And yes a clogged core can do this in early stages. Have a radiator shop blow the core out. When the heat gets cold is one heater hose(outlet) cold? If so, the core is plugged, if both are cold, the tsat, or low coolant level is your problem.

Actuator can be removed without removal of instrument panel. Remove console and the lower
steering column cover. Then remove in sequence shown in picture. Upper bolt can be
accessed through a hole just below, and to the right of column

tonight the heater just blew out cold air. even when we had driven some distance and it usually gets warm, the air coming from the heater was cool. I put some more antifreeze to see if this would help but the level was okay. Could it be a thermostat or something like that.

Hi there,

If your engine temp is still running normal on the gauge the thermostat should be ok. Check the heater hoses, are they both hot to touch, if not the heater tap or the control for the tap may of failed check this first.

Mark (mhpautos)

ok well my heater works fine at idle, you can sellect panel or floor or defrost and it will switch to anyone but when you have it on anything other then defrost when you are accelerating the heater switches back to the {defualt} defrost but if you catch the desired speed your going for and let up on the gas to keep the speed say 60 it will then about 10 sec after you continue doing 60 it will switch back to what ever the switch is on. I know the heater runs off the vac from engine and have disconnect the main hoses from firewall that com from engine and go to heater and tested them for leaks and they hold pressure and with truck running and heater on when i pressure the hoses the heater will work fine on any sellection by simply sucking on the hose and holding the pressure and they will not leak off. from their i hooked them back up and opened the hood and traced the hoses further, theirs a hose from the engine which goes somewhere under the front passenger fender in between the metal outer fender and between the actual fender well cover or wheel splash cover after looking i noticed a black bullet shaped cannister about 5 to 8 inches long that i think that hose from the engine is going too. then their is a hose coming out from that same location that splits off into 2 diff hoses wich one goes into fire wall to heater and other goes to 4x4 vac silinoid. from that splitter i unhooked the hose going into fire wall to heater and checked for leaks again and it still holds pressure. I am stumped the 4x4 works great and vac hubs lock in no problem and they are running off the same splitter that of the heater. I also would like any info about what the bullet shaped cannister is that is in wheel well between fender and its purpose please any suggestions or info would help thanks.

sounds like you have a vaccum leak in the heater door diapham. Does it open and close(go from floor to defrost) when you step on the throttle.a vaccum drop, as open throttle will lower the over all pressure and make small leaks more apparent.

when I turn the hot/cold air knob to blend the heat so that it is not so hot it just stays hot. My air conditioner works fine but only puts out luke warm air due to not being able to stop the hot air flow. What can be the cause of this?

chances are your blend door is sticking due to insufficent vaccum due to a bad vaccum hose or a bad electrical motor that controls the blend door ( it is a dealer only part).

could even be the switch.

My pickup runs great. MY temperature will not come up and my heater/defroster does not work real well due to a low temperature. I changed thermostat twice and still this does not change my temperature or my heater/defroster

Check to ensure your coolant level is up to normal. Also, if the head gasket is weak, it may allow engine coolant to seap into a cylinder and be thrown out through the exhaust. The engine may operate normally but there would more than likely be little or no heat , except there would be a tail-tail sign of a LOT of smoke coming from your exhaust. Check to see if both hoses connected to the radiator are getting hot. If only one is getting hot then you may have a clogged heater core.

when I turn my switch from heat to cold on the I get 100% heat. I have replaced the switch and also the blend air motor. On the passenger sid there is a damer with vacuum line on it if I take the vacum line off I will get cold air. The air comes out the dash hot wether the swich is in hot or cold. Is the air supose to bleed of on that damper.

OPERATION
CONTROL PANEL & DOOR ACTUATORS
Manual A/C-heater control panel is located near center of the instrument panel. A/C-heater controls include a function selector knob, temperature control knob and blower speed control knob. See Fig. 1 . Function selector knob actuates a vacuum selector valve that controls vacuum to door actuators. Door actuators control position of outside/recirculation, floor/panel and panel/defrost doors. Door positions determine airflow modes (panel, floor, defrost, etc.).
Temperature control knob controls an electric blend door actuator. Blend door actuator controls the position of blend door. Blend door position determines airflow around and/or through heater core. Each function selector knob setting affects system operation is as follows:
OFF
Vacuum is applied to inlet duct door, preventing outside air from entering system. Heater water control valve is at full vacuum, preventing hot coolant from reaching heater core. Vacuum is applied to floor/panel and panel/defrost door actuators. Blower motor and compressor will not operate in this mode.
MAX A/C
A/C compressor operates in this mode. Vacuum is applied to air inlet door, preventing outside air from entering system. Heater water control valve is at full vacuum, preventing hot coolant from reaching heater core. Vacuum is applied to floor/panel and panel/defrost door actuators. Airflow exits from panel vents. Blower motor is on.
A/C
A/C compressor operates in this mode. Vacuum is not applied to air inlet door, allowing outside air into system. Heater water control valve is at no vacuum, allowing hot coolant to reach heater core. Vacuum is applied to floor/panel and panel/defrost door actuators. Airflow exits from panel vents. Temperature setting can be changed manually. Blower motor is on.
Vent
Vacuum is not applied to air inlet door, allowing outside air into system. Vacuum is not applied to floor/panel door actuator. Vacuum is applied to panel/defrost door actuator. Airflow exits from panel vents. Temperature can be adjusted manually.
Floor/Panel
Vacuum is not applied to air inlet door, allowing outside air into system. Heater water control valve is at no vacuum, allowing hot coolant to reach heater core. Partial vacuum is applied to floor/panel door actuator allowing door to open partially. Vacuum is applied to panel/defrost door actuator. Airflow exits from panel vents. The A/C compressor operates in this mode.
Floor
Vacuum is not applied to air inlet door, allowing outside air into system. Heater water control valve is at no vacuum, allowing hot coolant to reach heater core. Vacuum is applied to floor/panel door actuator. Vacuum is not applied to panel/defrost door actuator. Airflow exits from floor ducts.
Floor/Defrost
Vacuum is not applied to air inlet door, allowing outside air into system. Heater water control valve is at no vacuum, allowing hot coolant to reach heater core. Partial vacuum is applied to floor/panel door actuator. Vacuum is not applied to panel/defrost door actuator. A/C compressor operates to dehumidify air and reduce windshield fogging. Airflow exits from panel vents and floor ducts.
Defrost
Vacuum is not applied to air inlet door, allowing outside air into system. Heater water control valve is at no vacuum, allowing hot coolant to reach heater core. No vacuum is applied to floor/panel door actuator or to panel/defrost door actuator. A/C compressor operates to dehumidify air and reduce windshield fogging. Airflow exits from defrost outlets.

In your response it said to see fig 1. But it was not there. Do you have a diagram of the heater a/c and damper operation? Also the vacum chart for the selector switch?

sorry i don't have a diagram of damper operation fig 1

let me know if you need anything else !

Where can I get a diagram like yours for my a/c heater dampers and vacume diampers/ selector switchs.
I have a hard time reading the ones on the website.
I would be willing to purchase theses acurate diagrams.

We use the diagrams in Mitchell1 .. you can purchase these on the link below .. at the bottom of my reply box ..


Find a car repair manual for your Ford Ranger Repair Question.

Heater problem
1998 Ford Ranger 6 cyl Four Wheel Drive Manual

I have a 98 ranger 4x4 and everythin good but the heater switches from panel or floor {position doesnt matter} to defrost when engine is at higher rpms and then goes back to switch selection when at idle like their is some sort of vacume issue but not exactly sure please help anybody.

You have a vacuum leak. The vents actuators are run by engine vacuum. When you accelerate, the engine vacuum drops so that is when you will notice the change. As you release the throttle, the vacuum builds so the vent has a better chance of working.

Check under the dash for leaks and under the hood. With the engine running, you may get lucky and hear a hissing sound where the noise is coming from.

Let me know if this helps or if you have other questions.

Joe

the system only blows cold air. I have been told to change the thermostat, water pump, heater control valve, climate control switch. I removed the glove compartment and found the air temperature control door operates like it is suppose to.

Please help

Hello –

To better assist you is your model the Ranger or Ranger Splash and what is the engine size in liter?

Did this just happen or have you been slowly loosing heat

How is the engine temp gauge look……normal operating range?

Once the engine is at operating temperature please feel the heater hoses going into and out of the firewall. Do they both feel the same……both hot or is one colder than the other?

The model is a Ranger Splash, 4.0 Liter engine, 95000 miles and this situation just happened. I had heat a few days ago. I just turned the temperature down a little, now it will not go back up. The temp gauge is normal, and both hoses connected to the heater core are hot.

Hello –

Thanks for the info………

So is this the same with the fan speed in any setting?

How does the AC feel……….does it feel the same temperature……..what I am looking for here is to see if there is a temperature difference…you select full cold yet the same warm air……you select hot…..the same warm air………..

You said the temperature control door was moving as it should……so you select hot and the door moves all the way……cold…..it moves the opposite way all the way

The temperature is the same at any fan speed. I am mistaken about the temperature control door, I found out it is not operating at all. If this is the same as the "blend" door, what do I need to do to get this back operational?

Thanks

Hello –

Thanks for the update.

On the control panel assembly is the temperature control knob. The temperature knob mechanically operates a cable through a cam mechanism to adjust the temperature blend door. Temperature blend door is in the plenum assembly. When temperature knob is in cool position (turned fully counterclockwise), temperature blend door stops airflow to heater core. When knob is in the warm position (turned fully clockwise), air is directed through the heater core. When knob is in intermediate positions, heated air is blended with cooler incoming air to achieve desired temperature.

Since this appears to be a mechanic, look at where the cable connects to the blend door. Then move the cable. If you can see the cable moving at the blend door connection then most likely the blend door is broken from the connector.

If you are turning the knob and the cable is not moving then it may be broken at the control panel assembly knob. I would check there.

If it is not broken there and still not moving then the cable may be broken. Check that

Heater problem
1998 Ford Ranger 4 cyl Two Wheel Drive Manual

I cant control the heat in the truck, the center switch that controls the temperature from hot to cold is not working, i got a new switch from ford and installed it but it still doesnt work. what else could be the problem?

I just recently (yesterday 1/17/10) fixed the heater in my daughters 96 Ranger. The problem was a broken blend door in the heater plenum. It makes it impossible to regulate or control the temperature. I bought a kit to repair it on ebay for 120 bucks and it now works great. Go to www.heatertreater.net for info. Good luck.