Heat not working

[Stanleyjd]

how do i go about trouble shooting why my heat doesnt work? its a 97 exp v8 with a lot of miles 197k to be exact thanks

 

[Dopler174]

It's probably a blend door problem. I would run a search for blend door and see what you find. I would also check for broken knobs. I had a friend run into that just the other day.

 

[BrooklynBay]

Turn the heat on, then feel both heater hoses. If one hose is hot while the other one is cool, then it could be a clogged heater core. I had this happen on mine.

 

[Stanleyjd]

ok i know its not a broken knob cuz its electronic. i also know that the heat went out slowly. i checked the lines running to the heater core and both are hot.

 

[NoogaX]

Had a series of similar problems on my 97 5.0 Limited two years back. My X has the electronic temperature control where you set the temp on the console by the way. If you are not getting any heat (defrost, floor or panel)then you my be looking at a new blend door motor (OMG what a PITA that is to fix - must pull the dash to get to the thing!! ) Since both hoses are hot on the heater core, sounds like the heater control is working and opening the water flow solenoid which allows hot water to go through the heater core (if it wasn't the core would be stopped up). If you have a manual get the schematic for the vacuum lines for the heater and a small vacuum pump (like the one to bleed brakes with) and start checking the vacuum lines. If you give me some details as to what is not working maybe I can give a little more advice.

Good luck!

 

[Stanleyjd]

yeah umm i dont have a brake vac pump but i know some one who does if i cant get their help i will buy one he said it was only 30 bucks when i was bleeding my brakes... thats cheaper than a shop and not like i wont use it again thanks

 

[Stanleyjd]

ok i went to my neighbors house that used to work at the ford dealership and he looked at it. he said the heater core seems to be working cuz he felt something hot. he checked the blend door and flipped it back and forth between hot and cold he said he could hear the blend door switching. he noticed that my engine temp was running a little low he said try replacing the thermostat it seems that its stuck open and replace the gasket. so i am going to try that maybe i will get lucky and that will be the source of my coolant leak too

 

[Stanleyjd]

ok so i just replaced the thermostat and the problem is the same. what else can it be?

 

[ma96782]

Usually the blend door will give you: Heat or A/C (but, not both).........so, IF it is that way........

Dead Link Removed



http://www.blenddoorfix.netfirms.com/




Dead Link Removed


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Did the heater blend door finally, using the Haynes manual.

They go to great lengths to describe and illustrate the two LH dash bolts and the lower RH bolt, which any fool could find in about one minute, but casually remark you should remove the defroster trim and remove the screws on the top. After squinting throught the windshield for a while, I saw there were 3 more large bolts on the top, two on the left above the gauges, and one above the glove box, as well as two sheet metal screws holding the defogger outlet to the firewall. The console would have been easy if they had told me about the tab at the back which had to be slid rearward after removing the four bolts they did tell me about, which was stuck and took nearly an hour to figure out and unstick.

Also, Haynes says to disconnect the main wiring harness on the LH and RH ends of the dash. I did not. They say to remove the LH A pillar trim and LH kick panel. I did not. They say to remove the PCM, and I did, but later for the life of me I can't see why. They say to remove the RH airbag, probably for safety, which I did, because it takes about two minutes. They say to remove the instrument cluster, I did not. They say to remove the heater controls, I did not. They say to remove the radio, which I did, but is unnecessary.

Meanwhile, I did get the dash loose, and by disconnecting the pushpins (not the connectors!) holding the RH wiring harness, I was able to move the dash rearward about a foot, easily enough to remove the heater. Even better, with full access, I was able, by putting a large screwdriver between the alternately the top and bottom of the door and heater case, to pop the old door out, and conversely the new door in. Took about 2 minutes. The manufacturer of the door (which I purchased on eBay for $15) includes a cutting template and steel repair panel for cutting open the top of the case to insert the door, and happily it was not necessary. Even better, if you were willing to take the car to a shop before hand, have the refrigerant removed, and later pay to have the refrigerant put back in, making it possible to completely remove the evaporator, I believe you could R&R the door without disturbing the dash. With the evaporator in the way, the firewall nuts for the heater case are accessible, but only David Copperfield could get the the blend door out with only five or six inches of clearance. Since I wasn't sure, I elected to do the whole job. While I had the heater out, I discovered the source of a rattle- the prior owner had lost a penny down in the defroster, which was running around inside the heater case, so pulling the case worked out OK for me.

Anyway, it should be a four or five hour job if done this way (five would be including a problem, like I had with the console), or more like two if you removed the refrigerant and evaporator. Quite nice, considering the $850 plus parts the local Ford dealer was offering to charge.

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Well, I finally had a chance to tear into it today and it is fixed. To whoever it is that came up with the free fix for the blend door,THANK YOU!!!!! Here is the steps if anyone elese is having this problem.

Step 1. Release and lower the glove box door and locate the actuator module on top of the air box. Unplug the electrical connector and take a large flat head screwdriver and pry it off of the airbox.

Step 2. Take a mirror and a flashlight and examine the hole in which the actuator arm fits. You should see the top of the blend door in the hole in which the actuator arm fits. it will either be split in half or it will be missing half of it. Visually compare where the blend door is broken off in relation to actuator arm and mark the angle through the actuator arm. Take a small drill bit and drill through the arm at that angle. Insert a small nail through the hole and trim it to approx. a 1/8th of an inch protruding from the arm on each side.

Step 3. Insert the actuator assy. back into the airbox and plug in the electrical connector. Remove the #36 fuse from the fuse block and trun the ignition on to reset the EATC and the actuator control. It disables the actuator control if it does not turn the blend door. Turn the ignition off and put the fuse back in. Start the car and test the system. If it works, remove the actuator assy and put a small drop of glue on the nail to secure it to the actuator arm. After the glue dries reinstall the actuator assy to the air box and replace the glove box door. FINISHED

This took me a total of about 20 to 30 minutes to perform and it works Great. The link to the fix can be found here. www.blenddoorfix.netfirms.com
This website gives the full detail and pics. Good Luck!

_________________________________

Well, I finally had a chance to tear into it today and it is fixed. To whoever it is that came up with the free fix for the blend door,THANK YOU!!!!! Here is the steps if anyone elese is having this problem.

Step 1. Release and lower the glove box door and locate the actuator module on top of the air box. Unplug the electrical connector and take a large flat head screwdriver and pry it off of the airbox.

Step 2. Take a mirror and a flashlight and examine the hole in which the actuator arm fits. You should see the top of the blend door in the hole in which the actuator arm fits. it will either be split in half or it will be missing half of it. Visually compare where the blend door is broken off in relation to actuator arm and mark the angle through the actuator arm. Take a small drill bit and drill through the arm at that angle. Insert a small nail through the hole and trim it to approx. a 1/8th of an inch protruding from the arm on each side.

Step 3. Insert the actuator assy. back into the airbox and plug in the electrical connector. Remove the #36 fuse from the fuse block and trun the ignition on to reset the EATC and the actuator control. It disables the actuator control if it does not turn the blend door. Turn the ignition off and put the fuse back in. Start the car and test the system. If it works, remove the actuator assy and put a small drop of glue on the nail to secure it to the actuator arm. After the glue dries reinstall the actuator assy to the air box and replace the glove box door. FINISHED

This took me a total of about 20 to 30 minutes to perform and it works Great. The link to the fix can be found here. www.blenddoorfix.netfirms.com

This website gives the full detail and pics. Good Luck!

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Aloha, Mark

 

[writemereal]

Disconnect your neg to battery, leave for at least 10 minutes to erase the codes or leave disconnected until repair is finished which ever is longer.

Check your temp sensor, 20 bucks for the part easy to do with your friend.

Then replace your themostate you took out. about 10 bucks.

Drive the truck for at least 20 minutes, gradual open throttle so the computer learns the new codes.

Should really help.

R