97 4cly, auto trans, while driving, turned the temp down in the truck. when I tryed to turn it back up it stayed on cold air. All hoises are hot. eng is hot. fan works. Will switch to all levels on dash, just will not regulate the temp back form cold to hot. As I said the heater core is working fine and the eng is hot so the thurmasat is working. it is just like a switch is shut off. Any ideas? Thanks Steve

 

May be a problem with the blend door actuator.
Use the search button for that as there are quite a few threads about it , many with pics.

 

Flush your radiator

 

I had the same problem on my 06. It was the blend door actuator. It is behind your glove box and a slight pain in the *** to get out. There is two 8mm bolts at the front and one 8mm bolt in the back that you can't see. If you have really good eyes you might be able to see the shaft under the actuator. Run your temperature control up and down and see if it moves, it moves slow. I couldn't tell with mine so I pulled it and it had died. About $40 and you will be in business if that is your problem. Don't worry about putting the back bolt in, probably take a hour or more and is not worth it nor needed.

 

While you have the actuator off stick your finger into the hole were the actuator goes and make sure your blend door's actuator socket didn't break or split. I suggest you read through this article. CLICKY

 

Could be the exact same issue mine was having. I got a year newer than you. I had the heater core flushed thinking that was the issue, still continued. It came down to either flushing it again or buying a new one for $400 some odd dollars, so I flushed it again but I used CLR instead of seafoam or whatever. Took a couple hours cuz crap upon crap upon crap was falling out of there but that was about a year ago and my heat is almost too hot again like when it was new

 

im having a similar problem to an extent. i was going to start a new post but this is close enough.
this takes place in about a 30 minute span and about 12 miles and a five minute stop. after work today i remote started my truck ( 97 ranger 2.3, 5 speed, 175k) and i get in it and its cold still and after five minutes with the heat on full blast on defrost the guage moves to the C line. its about 10 to 15 degrees here and snowing with a few inches on the ground. i drive about 5 miles to my womans house and still barely a change in temp guage. my heat is about luke warm. as im sitting waiting i turn off the heat on all controls and within 5 minutes the temp guage reads perfect and when i turned the heat on it was perfect. . for a few minutes then the temp guage dropped down again and back to luke warm heat. im lost and cold a little still. any ideas help comments or concerns? anything is a help as im not much of a mechanic. i know somethings but nothing to what this could be. i have a new water pump new coolant as of about 4 weeks ago. thanks in advance

 

Did you change your thermostat? That sounds like your problem.

 

im not sure. ive only had it for 4 months and ive had this problem for all of the cold winter so far. but three days ago we had freak 65 degree weather and the heat was great i thought my problem was solved but how sure are you that my thermostat is bad cause i dont want to get it replaced and find out thats not it. what are some other things that it could be

 

I agree with bratman2, start with a new thermostat. Test the new one before installation to maak sure it works. Some say the aftermarket thermostats are junk and recommend getting Motorcraft.You could also try some card board in front of the radiator to see if that helps to warm up engine to proper temp range. A cool running engine does not perform to its potential.

Just make sure when you change thermostat that you burp the cooling system of all aiir or you will have problems.

 

it works when I don't have the HVAC controls on. the hoses get hot and everything just when I use HVAC. then the guage drops. how hard is thermostat change. o have the 8 plug head

 

When you use heat you are diverting air and coolant through the heater coils. This lowers the coolant temperature because the heater coil is like a small radiator shedding heat. It is possible that the PO replaced the thermostat and used a 170 or 180. It could also be sticking open, most likely. I would never replace a water pump and coolant without replacing the thermostat. Even the premium Motorcraft thermostat is only like $10.00-$20.00 last time I bought one. So this is the cheapest thing to check or replace and most likely your problem. Also not very hard to do either.

 

Also like Larry above said check to make sure the new thermostat works. Years ago getting a bad thermostat out of the box was probably a 1 in 500. With everything out sourced to China it is more like 1 in 25 now. Brother just replaced his on his Silverado and came up here again wanting a code read. Guess what, thermostat again. That is also why I say get the Motorcraft one or a premium thermostat as Larry recommends also.

 

oh. I was expecting a little more expensive. uh what is all involved in changing the part.

 

Usually involves 3 or 4 bolts and a dollar or two gasket. You just recently changed your coolant so I would just drain a little (gal. maybe) out of the radiator into a clean container to reuse. I have not done it on your year model Ranger but I would doubt it is more than a 30 min. job taking your time. Look for an outlet on the engine towards the front. Radiator hose will run from that to the radiator. That will be your thermostat housing. Gasket will give you the bolt pattern for conformation. Maybe a little tube of the gasket sealant to hold the gasket in place. Coat both sides with as little as possible, let get tacky. Cross tighten in place, make sure the thermostat is in the right way, probably will only go in one way but I have seen some that could be installed backwards.

 

Got this from autozone.com repair info. You will need to register but is free. Also has pictures that did not copy and paste.

REMOVAL & INSTALLATION


2.3L and 2.5L Engines

See Figure 1

Drain the cooling system below the level of the coolant outlet housing.




CAUTION
When draining the coolant, keep in mind that cats and dogs are attracted by ethylene glycol antifreeze, and are quite likely to drink any that is left in an uncovered container or in puddles on the ground. This will prove fatal in sufficient quantity. Always drain the coolant into a sealable container. Coolant should be reused unless it is contaminated or several years old.






Fig. Fig. 1: Exploded view of the thermostat assembly for 2.3L and 2.5L engines

Disconnect the heater return hose at the thermostat housing located on the left front lower side of engine.
Remove the coolant outlet housing retaining bolts and slide the housing with the hose attached to one side.
Remove the thermostat from the outlet.
Remove the gasket from the engine block and clean both mating surfaces.


It is good practice to check the operation of a new thermostat before it is installed in an engine. Place the thermostat in a pan of boiling water. If it does not open more than1/4in., do not install it in the engine.

To install:

Coat a new gasket with water resistant sealer and position it on the outlet of the engine. The gasket must be in place before the thermostat is installed.
Install the thermostat with the bridge (opposite end from the spring) inside the elbow connection and turn it clockwise to lock it in position, with the bridge against the flats cast into the elbow connection.
Position the elbow connection onto the mounting surface of the outlet, so that the thermostat flange is resting on the gasket and install the retaining bolts.
Connect the heater hose to the thermostat housing.
Fill the radiator and operate the engine until it reaches operating temperature. Check the coolant level and adjust as necessary.

 

wow I don't think I could have asked for much more. that's great info. now I remember someone mentioned to burp the coolant for air. for that don't you just warm the vehicle with the rad cap off and squeeze the hoses a little? I had to do that before but never heard it called a term

 

Hi, my truck doesnt make heat idling and cools down wheb idking from normal temp. I replaced the thermostat to a 180 degree one but it still does the same thing. Also when i accelerate hard my engine temp drops. I have a 2005 2.3 2wd ranger. Thanks

 

Stat should be 195, did you get it in the right way round?

 

On mine the heater core was full of a muddy substance. I used a low pressure air to blow out the garbage. Made a mess all over myself too. It works perfect now.