Nik

Hi everyone! I am new to this site, and am hoping you can all help me. I actually had seen your other posts regarding heaters not working in Ford F-150s, but I want to give all info before I go buy a bunch of expensive parts. So here is my problem:

I have a 2002 Ford F-150 Lariat 4x4 Extended cab 4 door truck. Prior to this summer, my truck heater worked just fine. I ran the air conditioner more than normal this summer, due to the heat, and if the air wasn't on, it was in the off position. (I have the 3 **** dial system for climate control) I also ran the heater on a few occasions during late summer nights when I was cold. I hadn't run the heater in about a month or more, and went to switch it to heat toward the end of summer/beginning of fall, and I had no heat. It continued to blow cold air, as if my air conditioning was on. I read many of the posts on here related to the blender door and actuator door, and I also found some posts that gave us simple tests to do based on feeeling hoses. We thought it was the blender door at first, but upon performing the test of feeling the hoses leading to the heater, they were both cool.....which pointed to the coolant system. We brought the truck to our friend who works on many vehicles, and he flushed the radiator and put new fluid in. He also checked to see if removing the ***** and moving them with pliars would make a change, but no. Our friend believes its in the actual climate control **** panel (has microchip and hoses attached). If I turn the heater on, I turn it all the way to hotter setting and when the **** is moved from one to the next...it DOES switch from panel, floor, defrost and blend modes just fine. BUT....it does not get hotter...it stays cold/cool. However...if I switch it to air conditioning...it does get slightly colder than when it's in heat positions. I found all of these parts on ebay fairly cheap, but don't want to have to pay large labor bills for the replacement of actuator door or blender door, unless the chance is great that its the cause. I'd rather begin with easiest fixes for the possibilities of what's wrong. Could it be the actual **** panel (with the 3 *****) that could be causing this problem? Since the 3rd **** changes the modes from panel to floor to defrost to floor/defrost etc...would the blender door be ok? We have checked the fuse listed under climate mode switch, and fuse was good. Radiator has been flushed and new fluids put in. No signs of leaking from heater core, but if you remember...I was told the hoses that run to heater and out of heater were both cool to touch after truck ran for approx 15 minutes. Please tell me what you think, or if you need more information to base your decision. Like i said, i found all parts on ebay for discounted price, but don't want to have to pay a large labor bill for removing the entire dashboard and more to get to blender door, acctuator door, or heater core if I dont' have to. Thank you everyone who can respond with any suggestions.

13Harleyfan

You have to get hot water to the heater before you do anything else, could be a thermostat stuck open not letting the water get hot enough, the blend door has nothing to do with the water getting hot. Hopefully your friend knew to run the heater when he did your flush and fill, the heater core is the highest point in the cooling system and has to be on when filling the system or the cavity will not take in any coolant.

Nik

Thank you for your response. I will have to ask my friend if he did that. My husband said he felt the two hoses going to and from heater and they were both cool. I'm not sure if he felt the correct ones or not, but am guessing he did, so this is very helpful to know. We stopped the test at that spot, and the first thing was to check the fluid. My husband said fluid was full, but definitely needed to be flushed. The test said if neither hose was hot and both were cool, then it's probably low coolant or air in system. However.....I forgot to finish the test, now that ilook at it. It does say to check for hot water to the heater core inlet hose, and if it's not hot....to check the radiator cap for leaks and the coolant system. It also says to pressure check the system, and goes on from there. Not sure how to pressure check system or how to test a heater core for plugged or partially plugged system. I will need to have him re-check hoses to make sure this is path we need to be on, and will also ask my friend if he did these things (and if he ran truck during fill)! Thank you very much for your help!

13Harleyfan

Even if the heater core were blocked one hose should still get hot, if it's flowing through the heater core both hoses get hot. Don't take this personal but my method is KISS-keep it simple stupid. Don't buy any parts until you get hot water to at least one hose, try this, with the engine cold take off the radiator cap and start the engine, the water in the radiator should look like it is not flowing unless the thermostat is stuck open, you can feel the upper hose start to get warm and then you should be able to see the water start flowing in the radiator, it will go from cold to warm to hot so be careful. If water starts flowing right away-replace the thermostat. Cooling system 101. You can PM me if you have any questions.