99 Taurus NO HEAT OR DEFROST!!!

[ABE]

Could be an air lock. Try loosening the output from the heater core to purge any air. Do it when coolant is cool to avoid burns. Will not need much of a flow to fix. Not likely plugged with debris.

[paul53]

Originally Posted by ABE

Could be an air lock. Try loosening the output from the heater core to purge any air. Do it when coolant is cool to avoid burns. Will not need much of a flow to fix. Not likely plugged with debris.

Thanks, I'll try it tomorrow. I find it hard to believe it's plugged too, I really flushed the heck out of the the core and cooling system 2 months ago.
Isolated the core by itself and flushed with a garden hose.

[paul53]

Originally Posted by ABE

Could be an air lock. Try loosening the output from the heater core to purge any air. Do it when coolant is cool to avoid burns. Will not need much of a flow to fix. Not likely plugged with debris.

Hi,
I removed the connecting hoses from the core and put a garden hose to it from both sides. Ran it for awhile until the water was clear.

Topped off the antifreeze and ran until hot. The hoses going into the core and out are both hot. Inside heater is still blowing cool/warm air, nowhere as hot as it should be.

Any suggestions as what to do next?
Please educate me on how the heat gets into the cabin.

I would think the blower is behind the core and blowing the hot air into the vents?

What controls the temp of the heater air?

Thanks!

[ABE]

Originally Posted by paul53

Hi,
I removed the connecting hoses from the core and put a garden hose to it from both sides. Ran it for awhile until the water was clear.

Topped off the antifreeze and ran until hot. The hoses going into the core and out are both hot. Inside heater is still blowing cool/warm air, nowhere as hot as it should be.

Any suggestions as what to do next?
Please educate me on how the heat gets into the cabin.

I would think the blower is behind the core and blowing the hot air into the vents?

What controls the temp of the heater air?

Thanks!

OK, so the heater core hoses are both hot and the heater core is therefore hot, but the temperature of the air coming out of any of the vents (windshield, floor, panel) is not hot, is not as cold as outside air, and is heated just a little and the fan is working. Is this right?

The problem is with the Blend Door Actuator (BDA) which is an electronic controlled motor with a potentiometer to determine the door's position. The door determines routing of air through the heater core according to the temperature setting of the HVAC - hot to cold. Once the air is at the correct temperature it is directed by vacuum motors operating other doors that route the air to windshield, floor or panel or some combinations.

Since your air temperature is not according to your HVAC temperature setting, the BDA has failed in a partially open state. So the possibilities of problems are:
1. Fuse removed or blown. The fuse is the A/C fuse and I cannot remember whether it is in the passenger compartment or the engine compartment. I pulled this fuse to stop my A/C from cycling when it failed and found that I could not set the temp of the heater;
2. Failed wiring or ground in the circuit;
3. Temperature control switch in dash has failed or electrical connection dropped off or otherwise "failed";
4. BDA has failed and cannot move the blend door. Replacement requires removal of the dash and heater box. The part is over CDN$100. I am unsure if there is a remote test for the BDA.

Hope this helps.

[paul53]

Originally Posted by ABE

OK, so the heater core hoses are both hot and the heater core is therefore hot, but the temperature of the air coming out of any of the vents (windshield, floor, panel) is not hot, is not as cold as outside air, and is heated just a little and the fan is working. Is this right?

The problem is with the Blend Door Actuator (BDA) which is an electronic controlled motor with a potentiometer to determine the door's position. The door determines routing of air through the heater core according to the temperature setting of the HVAC - hot to cold. Once the air is at the correct temperature it is directed by vacuum motors operating other doors that route the air to windshield, floor or panel or some combinations.

Since your air temperature is not according to your HVAC temperature setting, the BDA has failed in a partially open state. So the possibilities of problems are:
1. Fuse removed or blown. The fuse is the A/C fuse and I cannot remember whether it is in the passenger compartment or the engine compartment. I pulled this fuse to stop my A/C from cycling when it failed and found that I could not set the temp of the heater;
2. Failed wiring or ground in the circuit;
3. Temperature control switch in dash has failed or electrical connection dropped off or otherwise "failed";
4. BDA has failed and cannot move the blend door. Replacement requires removal of the dash and heater box. The part is over CDN$100. I am unsure if there is a remote test for the BDA.

Hope this helps.

Hi Abe,
I got heat!!!!
Before, I checked heat output in yard, thought it was up to temp (temp gauge was in normal operating area).
Decided to take for test drive and heater output was hot. I put a temp probe in center vent above radio and the output got up to 115 degrees while driving. When I got back to house I watched temp in park and it went down to 98.5.

I appreciate all the info you posted as I will print it and save it for future reference.
Saved quite a bit of change this weekend.
Replaced alternator and got the heater going..
Dealer wanted $415 for the alt.
Not sure what they would have done with the heater but at $92 hour it would have cost me $$$.

If it was the BDA it would have been some big bucks. I'm sure it's about 4 hours labor pulling off the dash, etc.

Thanks again...... really appreciated good guys sharing their knowledge!

No I just need my tranny fixed and should be ok for a while.
Slipping intermit. in drive from dead stop, not so bad in overdrive.....

[ABE]

Hi Paul,
Glad it worked out for you, good job. Is your coolant up nearly to the top of the degas bottle (just below the black top) when cold? Ford's TSB suggests the higher level because of heater and cooling system performance problems on pre 2000 model Taurus.

When I replaced the heater core on my '93 the quote was CDN$880 at $75 per hour (not at Ford dealer). So you would be looking at over $1,000 since the BDA is over $100 and involves the same amount of work as actually replacing the heater core.

Sorry to hear about your transmission. You should start another thread on that so we can see how things develop and if there are alternatives. My '93 had the transmission replaced with used, twice and each one failed. Then I got it rebuilt for CDN$2,400 and it has performed perfectly for over 100,000 kilometers since.

[paul53]

Originally Posted by ABE

Hi Paul,
Glad it worked out for you, good job. Is your coolant up nearly to the top of the degas bottle (just below the black top) when cold? Ford's TSB suggests the higher level because of heater and cooling system performance problems on pre 2000 model Taurus.

When I replaced the heater core on my '93 the quote was CDN$880 at $75 per hour (not at Ford dealer). So you would be looking at over $1,000 since the BDA is over $100 and involves the same amount of work as actually replacing the heater core.

Sorry to hear about your transmission. You should start another thread on that so we can see how things develop and if there are alternatives. My '93 had the transmission replaced with used, twice and each one failed. Then I got it rebuilt for CDN$2,400 and it has performed perfectly for over 100,000 kilometers since.

Hi Abe,
Not sure what you mean by the degas bottle, I was calling it coolant overflow reservoir, on the left side with pressure cap?
If yes, the coolant is still very warm and about 2 inches from top.
Wow, big bucks for the BDA. Hope mine doesn't fail!

As for the tranny, I'm going to have the Ford dealer put it in a remanufactured one, around $2,300 with a 3 yr. 75k warranty.

I will flush the cooling system every year now. I did let it go to long as I wasn't aware of all the problems with them.

What's the mileage on your 93 & 2000 taurus's?

[ABE]

Hi Paul,
Yes, the degas bottle is the one with the pressure cap. The level 2" from top is below where Ford now recommends the cold level to be. It does not work the same way as the coolant overflow bottle used in earlier Taurus, since it does not force a full cooling system. Ford recommend the level as high as can be maintained without coolant overflow.

You should only need to change the coolant every 2 years. The additive package will easily last that long. Make sure the coolant stays somewhat transparent though.

My '93 has 240,000 kilometers and the 2000 has 135,000 kilometers.

That's an excellent price on a transmission with 3 years and 75,000 miles warranty.

Good luck.

[MikeyNC]

Originally Posted by MikeyNC

I have a 99 with the same problem. I'll be in touch in case one of us solves the problem. With no defrost, this vehicle is down for the winter. The heater hose is hot until the back side of the tee which connects to the heater core. A/C seems to be running constantly because of the high volume of water flowing from the condensation drain line. I'm thinking a stuck valve or switch controlling the temperature.

I had the heater core changed. Mechanic says it was stopped up. 100k miles I think justified the decision. By the way, he was able to change it out without draining and disconnecting AC lines. Good heat now!

[ABE]

Glad to hear everything works properly. Some mechanic to do that job without draining the A/C. Congratulations.