Hi folks, hope somebody can give an idea where to look.

I have a 2005 LR3, which I already knew it had some sort of problem with the HVAC/temperature controls: in the summer it would not engage the A/C, I had it checked and all is good mechanically, compressor, gas, etc. Multiple error messages were seen, the whole HVAC system would just turn on or off, heating only, and only at the front seats, and at least I was able to control the fan speed. No temperature control at all, nothing would work on the controls on the back seats either. But at least I was OK with heating working.

Now, a few days ago the truck went nuts: would not even start complaining of "park brake system fault" and shut down entirely, only park red warning light flashing on the dash. Frustrated, I just left it for a few days while I managed with my other vehicle.
When I came back to the LR3, the battery was completely dead. Absolutely zero charge (I must note I live in a very cold place... it's -20 Celsius out there now). Purchased a battery charger, gave it a good charge, and the truck came back to life!

Except... now the heater does not work at all. It blows air, the fan still responds to speed controls, but it's just cold air, no heating.
Unfortunately can't live without heating in this weather: I drove this morning and had to scrape ice from the inside of the windshield

I tried a couple basic things: tested battery voltage while everything off and while running, all values seem quite normal. Tried a hard reset (disconnect battery...), same results. Checked a couple fuses but could not find anything wrong, although at this point I'm already lost as to which fuse should I check, or even of this is a valid option.

Any ideas?

Thanks, and Happy New Year!

 

How is the coolant level?

Is the engine temperature gauge on the dash going up to normal temp?

There could easily be something going on with the electrical side of the system, everything is a bus signal, not just power and ground to the blend motors, but I would start with the basics of the system first, and move from there.

 

In the first link below there are a number of pdf's and files that describe how the heater and AC system is supposed to operate. Both front and rear systems are covered.

Near the bottom are Hard Reset instructions. You may as well try the procedure as a Hard Reset can cancel false error codes that inhibit operation of various systems. For me, a Hard Reset has got the radio going again; it does not solve many problems but the price is right and sometimes it will erase enough codes that a system will get going again.

Also included in the first link are files related to the fan box drain hoses disconnecting and allowing water to flow onto the carpet, not that that is todays immediate problem.

DISCO3.CO.UK Photo Gallery - Heater Air Conditioner System

You may have an alternator problem and I doubt the battery has a full charge; probably just enough to get the engine going. Even if the alternator is working, it cannot properly charge the battery; it might keep it OK sort of. It normally takes about a week of all nighters with my CTEK US3300 to fully charge the CaCa battery.

DISCO3.CO.UK Photo Gallery - Home > Member Galleries > bbyer


Towards the bottom of this set of files, are some files related to the alternator and regulator.

DISCO3.CO.UK Photo Gallery - LR3 miscellaneous




Hard Reset Instructions

In brief, to start the hard reset process, open the hood but close all doors and let your 3 go to sleep - no radio display etc and no key in the ignition. This will take a couple of minutes and do not open any doors until the reset is completed. (I find that it is often a good idea to have the drivers door window rolled down and the key in my pocket whenever fooling about the vehicle.) Also when I play with a car battery, I remove any rings I have from my fingers, also my watch.

Disconnect the ground battery terminal from the main starting battery.
Disconnect the positive battery terminal from the main starting battery.

The reason for this order is if a wrench or loose battery cable ends grounds to the body, no arcing or other bad things happen.

(I assume that you only have one battery in your 3. If not, disconnect the others as well and leave them disconnected until after all is done.)

Connect the negative cable to the positive cable. (NOT the battery.) You will need a short length, (a foot or so), of light gauge, (14 to 18 gauge AWG, insulated stranded copper), wire to span between the battery cable ends as there is not enough slack in the positive and negative battery cables for the ends to touch each other.

Hold all together for about a minute or more, (at least two minutes), as you are discharging memory modules within the engine computer and elsewhere. Then it is suggested you then just let all sit disconnected for say ten minutes, (minimum five minutes), prior to commencing to put the battery cable ends back on the battery posts per the following order.

Reattach positive terminal to the main starting battery positive post.
Reattach negative terminal to the main starting battery negative post.

Start engine and hopefully no or fewer warning lights.
Reset time on the radio - note that the station presets are still there as not everything is erased. Nothing much else needs resetting either.

You can now connect up the other batteries if you have a multiple battery setup.

This is a link to a thread in disco3 re the hard reset procedure.

http://bit.ly/14WXXR1

http://www.disco3.co.uk/forum/topic19547.html

This is a link to a thread on Disco3Club re the hard reset procedure.
Disco3Club The Discovery 3 and 4 Owners Club • Login

 

Thanks for the tips, I'll try to see what I can, as weather permits. It's -30 today... I can only stay out for a few minutes at a time before my fingers freeze...

 

Given -30C, your 3 must be either in Northern BC or Northern Alberta; well perhaps Yellowknife as I know there is a 3 up there as well - only Siberia is colder.

I am in balmy Edmonton, at least maybe later in the week it will be -- and it is of course more than just one's fingers freezing.

 

First of all, I'm a Canuck too! You are forgetting Winnipeg in your list! It's insanely cold these days here.

Anyway, back to business: checked coolant, all good; hard reset, already tried yesterday. Today I took out the climate control module in the dash, cleaned the harness connectors (some looked like they had some rust) put it all back, still the same.

The controls respond just as before the failure: on/off and fan speed, I can hear some things moving back there when I turn it off (that's a good sign I guess), but it still blows cold air.

Unfortunately I lack tools for deeper diagnosis, and we need the LR3 for our daily routine quickly, so I'm afraid we have no choice but to take it in for a costly repair. Will report back when I get some progress.

 

Some things I try to forget - and when the mosquitoes gang up, they can carry a 3 away.

I found as below regarding a heater/ AC system self test and then a followup automatic self calibration if the test fails.

Since hot water is always supposed to be flowing thru the heater core, both summer and winter, the problem is probably the air door that regulates air flow thru the heater core - that is, it remains closed. As to why, probably it is something electronic which is bad and you will need the dealer however it just occurred to me that perhaps water drips/condensation has frozen an air door shut.

Can you park your 3 in a heated underground parking garage, that sort of thing? Winnipeg must have more than Igloos I am certain, or even spend a couple of quality hours in a do it yourself car wash doing a good interior and exterior cleanup. In other words, allow some time for the interior to warm up and if there is any ice within, to melt.

Something within the heater just might be frozen - snow melt water thru the cowl and then freezing - well a thought.


Heating AC System Test


The issue with the Heater may be the Control Lever - Recirculation flap or some other flap.

With ignition off press and hold the ECON & RECIRC buttons whilst turning ignition on (no need to start car).

The control module will then compare the current HEVAC actuator motor positions with the values stored in the module and will indicate an error by flashing the ECON LED.

If there are no errors, the LED will go out and the system will function normally.

To confirm that there are no errors, turn the ignition switch to the OFF position, then back to the ON position.

Observe the operation of the programmed defrost LED.

If there are errors present, the programmed defrost LED will flash and the system will attempt to calibrate itself.

 

So... reporting back. I took my LR3 to the dealership and in a nutshell, it seems like it was a wiring problem.

They took it all apart, unplugged all cables, tested cables and motors, put it all back together... and it worked! They said they found cables improperly routed inside the dash suggesting someone worked on it before (could very well be, I'm probably the 3rd owner of this truck).

So perhaps some connectors or harnesses needed reseating after years of service... or the extreme cold made some things shrink and disconnect... and maybe the battery discharge was unrelated... Who knows. At least I did not have to break the bank for replacing costly parts.

Thanks for all the help!

 

Thanks for the update.

The results were good news then; nothing broken so to speak, just some sort of connector issue that would I presume not tell the air doors to open, or at least the door that allows air flow thru the heater core.

If someone in the past was in behind or underneath fooling with the wiring connectors, if you ever get some real difficult problem, consider looking at the connector that feeds into the rear of the instrument panel.

For some reason, people remove the instrument panel, and when reconnecting the primary connector, do not do it quite correctly and impossible to find problems start to occur - all due to the not quite attached wiring connector - something to keep in mind.

 

We have a LR4, 2013 model, and it seems when the battery is flat, and there is a red warning, the HVAC system blows out cold air at quite a high speed and there are no lights or controls available to use. When the battery is charged more, the HVAC is operational again. I am going to buy a new battery anyhow, but has anyone else had this issue?

Thanks
Simon