Erratic Climate Control

[ridindirrty]

Hello everyone. Having some issues with my climate control. Initially I would fire up the heat and the yellow lights on the control box would start blinking. Determined through research this indicates a fault of some sort. Most of the time it would work fine but like any problem it's getting progressively worse. The issue appears to be with the blend door being out of position as the heat does not go where directed . Other times it works absolutely flawlessly which makes me think it could be something like a dirty connection. Ever since i've owned the car the temp display has had a habit of flashing back and forth between celcius and farenheit but there has never been a problem with the heater functions themselves. Anyone had a similar experience? What's involved in getting that control box out ? Thanks for any suggestions.

 

[OldSchool1]

Climate Control Problem

... Other times it works absolutely flawlessly which makes me think it could be something like a dirty connection. Ever since i've owned the car the temp display has had a habit of flashing back and forth between celcius and farenheit but there has never been a problem with the heater functions themselves. ...

If your Mark VII is a 1984 - 1989, replace your Ignition Switch (see my signature).

Verify that the standing voltage of your battery is at least 12.3 volts disconnected from everything. If not, replace your battery.

While running, verify that your alternator is maintaining base voltage plus 1.4 volts. A 12.3 volt battery and a properly charging system should read at least 12.3v + 1.4v or 13.7 volts. If not, replace the alternator AND the voltage regulator.

Once these things have been done and voltage verified, your problem should go away. If not, then you need to start cleaning and re-securing grounds.

 

[ridindirrty]

Hi again. The battery and alternator were replaced just a few months ago. How would the ignition switch affect the climate control? Which grounds would I be cleaning? For the control unit? I don't seem to have any other electrical problems. The car is an '87 Blass. Thanks for responding

 

[OldSchool1]

Correct The Basics First

Hi again. The battery and alternator were replaced just a few months ago. How would the ignition switch affect the climate control?

All accesories except for the horn and flashers, goes through our ignition switches. Don't confuse the ignition switch with the key cylinder.

Which grounds would I be cleaning? For the control unit?

All connections for the control unit and the charging system but first, verify that the standing voltage (base voltage) of your battery is at least 12.3 volts disconnected from everything. If not, replace your battery. While running, verify that your alternator is maintaining base voltage plus 1.4 volts. A 12.3 volt battery and a properly charging system should read at least 12.3v + 1.4v or 13.7 volts. If not, replace the alternator AND the voltage regulator.

Once these things have been done and voltage verified, you can then proced with troubleshooting (if needed).

I don't seem to have any other electrical problems. The car is an '87 Blass. Thanks for responding

You're welcome.

ALL PRE 1990 LINCOLN MARK VIIS SHOULD HAVE THEIR IGNITION SWITCHES REPLACED.

Thank us when your ride is fully functional

 

[ridindirrty]

Back To Normal

Hello again. I recently had a heater hose burst on the car. When the hose was changed my cooling system was flushed and the coolant replaced. Since this service my climate control seems to be functioning normally again . I don't quite see the connection myself but could extremely old and dirty coolant somehow have been causing this problem?

 

[OldSchool1]

Accessories R Us

Hello again. I recently had a heater hose burst on the car. When the hose was changed my cooling system was flushed and the coolant replaced. Since this service my climate control seems to be functioning normally again . I don't quite see the connection myself but could extremely old and dirty coolant somehow have been causing this problem?

Possible but not probable

The problem you mentioned in your first post is related to the blend door (electrical) or refrigerant charge (pressure). Also, we currently have higher temperatures here in May than we did in your February post.

Our 1987's MUST have the ignition switch replaced before successfully tracking down electrical issues in the accessories.

 

[Elessee]

Hello again. I recently had a heater hose burst on the car. When the hose was changed my cooling system was flushed and the coolant replaced. Since this service my climate control seems to be functioning normally again . I don't quite see the connection myself but could extremely old and dirty coolant somehow have been causing this problem?

Well... i can see a connection between the heater hose's and core's functioning properly, and the climate control..

i mean like.. there must be temperature sensors that detect heater water temp.. You might notice the climate control, although it's "on", won't even try to heat immediately upon starting a cold engine. It just sits and waits for water temp to rise. I think i remember reading the fans wait..

So what exactly caused that hose burst? And why did they flush the system?

Maybe the hose (or a connection) was clogged up with rust and dirt... Maybe the partial clog caused unusually high pressure in one area of the flow. Combine very hot water with an old, weakened hose, and high pressure and it might pop..

And maybe the core wasn't getting a good flow of water, and one of the temperature sensors was reading temps that were way too hot or too cold to allow all the other things to operate, like fans and air-mixing doors.
Maybe, due to poor flow, two coordinated sensors read widely different temps so the system wouldn't or couldn't run right..

-----
(as an aside, I just installed Firefox Browser.. IE was slow and locking up lately.
This spell checker option (while you type) is nice.. it underlines misspelling in red. But , afaik, it just checks, and can't correct misspellings so you have to know the correct spelling...)

 

[OldSchool1]

Microsoft's cooling electrical hoses

Well... i can see a connection between the heater hose's and core's functioning properly, and the climate control..

Functioning properly, yes.
Causing the climate control to flash, no.

i mean like.. there must be temperature sensors that detect heater water temp.. You might notice the climate control, although it's "on", won't even try to heat immediately upon starting a cold engine. It just sits and waits for water temp to rise. I think i remember reading the fans wait..

There are two water temperature sensors. One is just above our oil filters and serves to sense water temperature and oil level. The other is in the inlet hose for our heater cores. If the coolant temperature (or temperature inside the hose at this point) is low, say under 140 degrees, the sensor or switch is open and will interrupt auto blower motor speeds so as not to blow cold air into the cabin when the driver is requesting heat. Neither sensor should cause the flashing error of the climate control.

Start here. http://thelincolnmarkviiclub.org/documents/tech/eatcSelfTest1984-1987.pdf

So what exactly caused that hose burst? And why did they flush the system?

Flushing a system is normal preventive maintenence. The mechanic may have justseen some calcium or flouride build-up (from using tap water) and decided to flush the system while replacing a hose. The worst case scenario for a blow hose is a blow head gasket.

Maybe the hose (or a connection) was clogged up with rust and dirt... Maybe the partial clog caused unusually high pressure in one area of the flow. Combine very hot water with an old, weakened hose, and high pressure and it might pop..

Yup.

And maybe the core wasn't getting a good flow of water, and one of the temperature sensors was reading temps that were way too hot or too cold to allow all the other things to operate, like fans and air-mixing doors.
Maybe, due to poor flow, two coordinated sensors read widely different temps so the system wouldn't or couldn't run right..

Yup. Different sensors will throw different codes. But again, none of what was discussed above means a hill of beans if the ignition switch is original.

-----
(as an aside, I just installed Firefox Browser.. IE was slow and locking up lately.
This spell checker option (while you type) is nice.. it underlines misspelling in red. But , afaik, it just checks, and can't correct misspellings so you have to know the correct spelling...)

Anyone who owns a legal and registered version of Microsoft's Internet Explorer with free automatic updates has received flawless surfing with all of the bells and whistles.

 

[Elessee]

Anyone who owns a legal and registered version of Microsoft's Internet Explorer with free automatic updates has received flawless surfing with all of the bells and whistles.

Actually it's a brand new computer.. less than a month old. WinXP SP2. It has IE7 and is a bit different than IE6, with which i was familiar.

So, I attempted to configure the program according to how I like things and admit I may have messed something up while adjusting cookies or pop-ups and/or security settings.. who knows. All I know is half the time it'll start to load a web page, and freeze up.

(btw, you misspelled three words .. maintenence, justseen and flouride. I see them underlined in red. (I right clicked to copy/paste those 3 words and when i did, similar, correctly spelled word-suggestions appeared at the top of the right click menu. Selecting one replaces the misspelled word... so Firefox can sort of correct spelling for you..)

-----------
I don't know exactly why, but i strongly suspect that whatever caused the burst heater hose also had some degree of a negative impact on the climate control's operation and stability. They just seem to be related somehow...

 

[OldSchool1]

mispelling electrical switches

Actually it's a brand new computer.. less than a month old. WinXP SP2. It has IE7 and is a bit different than IE6, with which i was familiar.

So, I attempted to configure the program according to how I like things and admit I may have messed something up while adjusting cookies or pop-ups and/or security settings.. who knows. All I know is half the time it'll start to load a web page, and freeze up.

(btw, you misspelled three words .. maintenence, justseen and flouride. I see them underlined in red. (I right clicked to copy/paste those 3 words and when i did, similar, correctly spelled word-suggestions appeared at the top of the right click menu. Selecting one replaces the misspelled word... so Firefox can sort of correct spelling for you..)

-----------
I don't know exactly why, but i strongly suspect that whatever caused the burst heater hose also had some degree of a negative impact on the climate control's operation and stability. They just seem to be related somehow...

TOO FUNNY!
My signature on another forum says this, verbatim.
"Expearence is the abillity to reconise a misteak befor you mak it agan."
I'll debate Microsoft with you in another thread

Blown hoses are mechanical failures. I don't see the relationship to error codes on the climate control. Maybe RidinDude can tell us what he has or has not done since then.

I'll run my spell checker now

 

[Elessee]

Blown hoses are mechanical failures. I don't see the relationship to error codes on the climate control.

Evidence to the contrary is that ridindirrty's climate control problem went way with a flush and a new hose. I'm not gonna search for more before that evidence is confirmed or denied.

Where is he anyway.. we seem to care more about his dirrty ride than he does..

 

[OldSchool1]

Evidence to the contrary is that ridindirrty's climate control problem went way with a flush and a new hose. I'm not gonna search for more before that evidence is confirmed or denied.

Where is he anyway.. we seem to care more about his dirrty ride than he does..

I concur (without automatic spell check).

 

[Ricks90billblass]

IE 7 conspiracy theory

A burst hose might be just because it was old. Always good to flush the cooling system every 2 years, and use a chemical flush. It will make your engine happy and keep you off the side of the road.
As well, your ABS will work better if you drain and flush your brake fluid every year or two. Use DOT-4 fluid, not DOT-3 (my preferrence is Valvoline semi synthetic brake fluid.)

I have noticed that IE 7 has slowed down dramatically in the last 8-10 months. Coincidently (sp) IE8 came out and claims to be faster than IE7. I installed it and My web surfing is much faster. Maybe microsoft with all their updates made it slower to make IE8 look fast??? Just a thought...

 

[OldSchool1]

A burst hose might be just because it was old. Always good to flush the cooling system every 2 years, and use a chemical flush. It will make your engine happy and keep you off the side of the road.
...

Yup.

 

[ridindirrty]

Yes I Care

Rest assured I care plenty about my ride gents. Alas I do have other concerns than my car from time to time so i may not respond as quickly as some. Just thought it was an interesting outcome and the info might be of some use to the Mark vii faithful. Trust me, if i didn't care my poor BB would have been crushed some time ago .

 

[Elessee]

Of course you, I and everyone else cares about these cars or we wouldn't put up with them..
We were just hoping you could provide a few details that might settle the question of whether the burst hose / replacement and/or flush were directly related to the climate control troubles.

Did a service shop change the heater hose for you? If so, did they offer any thoughts on why the hose burst?
Did the shop suggest a system flush? If so, did they explain why a flush might be needed?
Did you mention the erratic climate control and was there a response?
-------
If you did the work yourself, what did the hose look like.. for instance, was it bulged and cracked at a connection, or was it split open in the middle? Did the hose look newish and otherwise healthy? What did the old coolant look like..

---------

About the suggestion to flush the system regularly.. Since nothing is as simple as it seems, it's gotta be done correctly, imo.

In preparation for a longish trip I once made the mistake of adding an anti-rust additive before flushing an engine (old 283 Chevy) and after following procedure instructions on the can, finally flushed with a garden hose / heater hose adapter.

Lots of garbage was purged. Very rusty, dirty water, with a significant amount of rust flakes and particles at the bottom of the tub.

However, little did I suspect that most of the rust flakes loosened by the additive remained settled in the lower regions of the engine block and cooling system. The force and volume a garden hose provides just isn't enough to pick up the heavy crud and move it out..

The engine's water pump does providing enough flow to pick up and move any loose flakes of junk... which then clog any orifice smaller than themselves (like radiator tubes).
The car overheated about 10 miles from home and every ten miles thereafter... until a road side garage used a real power-flush machine on the system.

 

[ridindirrty]

We were just hoping you could provide a few details that might settle the question of whether the burst hose / replacement and/or flush were directly related to the climate control troubles.

Did a service shop change the heater hose for you? If so, did they offer any thoughts on why the hose burst?
Did the shop suggest a system flush? If so, did they explain why a flush might be needed?
Did you mention the erratic climate control and was there a response?
-------
If you did the work yourself, what did the hose look like.. for instance, was it bulged and cracked at a connection, or was it split open in the middle? Did the hose look newish and otherwise healthy? What did the old coolant look like..

The work was done at a shop, i was stranded, i had no choice. No conclusion was offered other than the hose was old and rotten. They suggested the flush, the coolant was nasty, it seemed like an opportune time to get it done so i went with it. I never mentioned my climate control, these guys would have no clue what to do with a thing like that (trust me). I tracked down the problem myself before the car even went in, it was a burst heater core hose, split down the middle, about an inch or so. The hose didn't look awful but once it was off you could see the rot happening on the inside.

 

[OldSchool1]

Bussing :q:q:q:qrols With Spel Chekers

The work was done at a shop, i was stranded, i had no choice. No conclusion was offered other than the hose was old and rotten. They suggested the flush, the coolant was nasty, it seemed like an opportune time to get it done so i went with it. I never mentioned my climate control, these guys would have no clue what to do with a thing like that (trust me). I tracked down the problem myself before the car even went in, it was a burst heater core hose, split down the middle, about an inch or so. The hose didn't look awful but once it was off you could see the rot happening on the inside.

I concur with Elessee. We're not busting your chops, (not about repairs anyway) but we do need more detail when discussing this stuff. The more you provide, the better we can reply. Internet diagnostics are hard enough as is.

Anyway, based on what you've typed about an old hose, we can dig it dying and normally under the worst situations too like being out of town the day before payday. One of my 1984s has like EIGHT hoses on the cooling system. Each time I replaced one with a new hose and clamps, another would blow. Simply put; the system would come up to regular operating temperature, and the weakest hose would give up the ghost until finally, I had replaced ALL of the hoses for the system to actually maintain pressure (then the water pump gave up the ghost<g>)!

What may SEEM like a little detail may be crucial to hellping you keep your ride on the road. We don't ask for details to bust your stones (that's what they make mirrors for) but so that we don't look like total idiots when we tell you to replace the widget when your gadget stops working.

So. Back to the climate control.

Did you read the Electronic Automatic Temperature Control article I pointed you to?

tsk tsk tsk if you didn't. Just one more thing for us to bust on you about

*This post was NOT spell checked. At 4:34 AM, I really dgaf <g>.

 

[Elessee]

here's the thing..

The automatic temperature control has only three input sensors by which it operates and makes all it's decisions.

After you set whatever climate conditions you prefer, the micro-processor reads:
1) Temperature inside the car
2) Temperature outside the car, and
3) Engine coolant temperature.

Using just those three inputs, it then controls
a) the A/C compressor clutch.
b) the blower speed
c) the blend door position
d) the panel/floor door position
e) the panel frost door position and
f) the recirculating outside-air door position

Now, it seems reasonable to me that if any of the three sensors is out of whack, one should expect that the computer is going to have a hard time deciding what to do.. it might even make a mistake or get confused..

-----------------------
Consider that one of those three input sensors (engine coolant temperature) is smack in the middle of a "rotten" heater hose on the brink of failure. Further, the coolant passing by it, if any, is "nasty".

Since this sensor's accuracy represents fully 33.3% of the computer's total input, I can easily imagine that a blend door might be left ajar when it's not supposed to be..

--------
Another of Firefox's little pleasantries .. the way it's "Find" feature works is far superior to IE .. and it's so fast.... i mean zero-delay. Searching huge .htm pages is no longer a chore.

 

[OldSchool1]

Sensing When FireFox Blows Cold Air

...3) Engine coolant temperature.
...
Now, it seems reasonable to me that if any of the three sensors is out of whack, one should expect that the computer is going to have a hard time deciding what to do.. it might even make a mistake or get confused..
...

KindaSorta. (Good thinking though)

Sensor 3 only controls the blower motor speed controller when the ECC is set for auto or between 65 and 85 degrees. 60 or 90 overrides the blower motor speed controller AND the in hose temperature sensor. With this in mind, there are about 24 different scenarios that could start with a completely drained cooling system yet still result in a proper working ECC.

If the OA is cold and the coolant temp is cold, then lock out the blower until coolant temp rises. When coolant temp rises to factory setting, close the switch and allow the ECC to do it's thing.

 

[Lincolnlov]

KindaSorta. (Good thinking though)

Sensor 3 only controls the blower motor speed controller when the ECC is set for auto or between 65 and 85 degrees. 60 or 90 overrides the blower motor speed controller AND the in hose temperature sensor. With this in mind, there are about 24 different scenarios that could start with a completely drained cooling system yet still result in a proper working ECC.

If the OA is cold and the coolant temp is cold, then lock out the blower until coolant temp rises. When coolant temp rises to factory setting, close the switch and allow the ECC to do it's thing.

Question for Old School!

JY, Would the information link you provided for the 84-87 Mark(s) be at all helpful for dealing with my 90 SE? I had a similar problem several years ago (12) which resolved itself. Problem reappeared about 10 days ago and has not resolved itself this time. Just thinking of you makes me hungry for a Phili chease steak!

 

[OldSchool1]

A Bajillion Fuctioning Cheesesteaks

Question for Old School!

JY, Would the information link you provided for the 84-87 Mark(s) be at all helpful for dealing with my 90 SE? I had a similar problem several years ago (12) which resolved itself. Problem reappeared about 10 days ago and has not resolved itself this time. Just thinking of you makes me hungry for a Phili chease steak!

Thank you.

I'm little confused by your question.

The controllers are similar but different.

With that said, yes. MOST of the functions are the same yet the early 84-87 ECONO funtion was combined with the defrost and auto functions the late 88-92 models.

Start another thread and detail your problem. There's a bajillion people on the net. I'm sure ~someone~ can help you

Cheesesteaks are the stuff.