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scruge
January 7th, 2004, 02:07 PM
I'm HOT for someone to help!
I've got a 99 Navigator with Automatic climate control that seems to have a mind of its own. I'm the original owner and about 2 years ago the climate control started acting up. I've had it into the dealer 3 times now and it keeps coming back as "Not able to duplicate problem" .
The problem is when the system acts up, usually after 20-30 minutes of driving, it under reads the temperature by 12-15 degrees. Meaning, when its working properly and the cabin temp is set for 76 degrees and a thermometer used to report the actual cabin temp is reading within a few degrees of the set point. When the climate control malfunctions the actual cabin temp raises to 88-90 degrees.
There are several things I can do when it malfunctions
1. I can run the setpoint down to 64-61 degrees and the system will regulate around this temp until it decides to start working again at which time it then attempts to bring the cabin down to an actual 64-61 degree range.
2. I can sometimes turn the system off and then back on which works for a brief spell.
3. Stop and restart the car.

An additional note. When the system malfunctions it also misreads the outside temp by displaying a temp 12-15 degrees below the actual outside temp.

I'm familiar with running the climate control self test and I'm above average with working with electronics at the discrete component level. I'd like to attempt repairs myself if I only knew where the 3 temp sensors were and what their normal readings should be using an ohm meter, provided they are thermistors ( I assume that's what Ford uses verses thermo-couples).
The 3 sensors my Haynes manual shows in the wiring diagrams are "ambient (outside), Sunload (radiant) and In-car (cabin).

Thanks in advance for any advice.

Bluegrass
January 9th, 2004, 11:29 PM
Sorry I don't have any info on your machine.
Hope someone stops by to give you a steer or post in the forum on your Nav.

ekooke
January 10th, 2004, 10:37 AM
Those three sensors on most vehicles are:
Ambient - at hood latch brace behind grille.
Sunload - on top of dash near windshield.
Cabin - on front of dash (small slotted grille)

scruge
January 20th, 2004, 05:31 PM
Thanks eKooKe,
I've had some time to look into this problem further.
1) I can't perform the EACT selftest per my haynes manual. (press OFF and Floor together then release and press AUTO within 2 secs) I did find if I turn the ignition off and then pressed OFF and FLOOR together while turning the ignition to on and then press AUTO it appeared to do some sort of test. Like a count down timer for 15secs and then display reverts to lamp test mode.
Not sure what is happening. Someone suggested because the selftest didn't work per instructions that it was bad.
I was wondering if maybe Ford has changed the procedure.
2) Are you pretty sure about Ambient temp sensor location? I was under the impression it was located around the fresh air inlet. At least thats where my manual show it on towncar. I thought the one near latch was for ECM.

[ January 20, 2004: Message edited by: scruge ]

ekooke
January 20th, 2004, 06:53 PM
quote:Originally posted by scruge:
Thanks eKooKe,
2) Are you pretty sure about Ambient temp sensor location? I was under the impression it was located around the fresh air inlet. At least thats where my manual show it on towncar. I thought the one near latch was for ECM.

[ January 20, 2004: Message edited by: scruge ]


I'm not sure (for sure) about much of anything any more. It's just that every Ford-made vehicle I've seen under the hood or owned for the last 20 years or so has had the outside (ambient) temp sensor mounted on the lower hood latch brace, behind the grille. Take a look; it's pretty prominent, if it's there. If it is there, disconnect it, and then look at your in-vehicle thermometer; it should now read -40º (or something meaningless). smile.gif

ekooke
January 20th, 2004, 10:50 PM
quote:Originally posted by ekooke:



I'm not sure (for sure) about much of anything any more. It's just that every Ford-made vehicle I've seen under the hood or owned for the last 20 years or so has had the outside (ambient) temp sensor mounted on the lower hood latch brace, behind the grille. Take a look; it's pretty prominent, if it's there. If it is there, disconnect it, and then look at your in-vehicle thermometer; it should now read -40º (or something meaningless). smile.gif

P.S.: Throw that Haynes manual away (or use it as a doorstop) and invest in the FACTORY Shop Manual for your vehicle - You'll be glad you did.

scruge
January 24th, 2004, 05:23 AM
I realize the haynes is lame. But the Helms is $500, which seems a bit much to me. Considering I've always in the past bought the Helms for $150 or less, but for some reason they really jacked the prices when I last checked in 99. Its seems I checked again in 2000 when I bought a new explorer and they were still up there.

ekooke
January 24th, 2004, 10:57 AM
scruge,
I just looked at the Helm site, and the shop manual for the 1999 Navigator/Explorer (2 books) is $180.

scruge
January 28th, 2004, 08:19 AM
You're right if all you get is the basic shop manual. I've always bought the 3 manuals. Shop, Emission, & Electrical which add up to $413 + TSH = big bucks. I've found I use the emission manual more than the shop.