I have a 2000 Range Rover and dropped in a used control head that I was told was fully functioning and tested good. The unit is from a reputable breaker that I have used for parts many times in the past.

My existing control head seems to work well, but the fan control knob gets stuck some times and the LCD screen doesn't display. So, purchased the used control head and dropped it in fully expecting a working LCD screen and functional HeVAC controls. The LCD screen turned on bright then immediately faded away. Before doing so, it showed me the book and ! symbol. I was not able to turn the blower fan speed up or down at all. The knob turned smoothly and freely but did not affect the fan speed at all. In fact, the fan turned off. I removed the used unit and reinstalled my old unit and all worked as it should with the exception of the LCD screen.

My working assumption is that the new (used) unit has stored faults that I need to clear. Is this correct or is the it more likely that the new unit is bad? What code readers work to read the HeVAC ECU?

Thanks,

climbed under the Range Rover today and cleaned out the drains. both were dry and clear as far I could tell.

but, now I have no way to test since the compressor has decided to stop kicking on.

I've checked all the fuses and they are all good. condenser fans do kick on. i did pull the clutch plate off and remove one shim. that's assuming the shims are the small washers inside clutch plate shaft. now the clutch plate spins with the vibration of belt moving. did I remove the wrong shim?

thank you, sir.

now I have something to do tomorrow.

On our last road trip we had the duct work dumping quite a bit of condensation on our feet as we were driving.

Is this clogged evaporator drains or something else? Where should I be looking? Just the drains behind the front tires?

New battery fixed the issues until it, too, ran dry. My daughter called to let me know that the AC quite working, the dash lights came on, TC stopped working, etc. as my wife and I were half way between St. Louis and Tulsa.

I was able to confirm that the alternator had failed, or more specifically, the voltage regulator. The code reader gave a reading between 17 and 18 volts at all times. I managed to track down the only P38 alternator in town(because, of course, i'd left the spare in the basement) and install it Saturday morning, three hours before my daughter's graduation. Both alternator and battery tested good and we were able to make the 400 mile drive back home with no issues.

Last week the RR decided not to start at all. Per my daughter, starter did nothing just one tick when she turned the key. So, she replaced the battery
and all seems good now. I did ask her to have the alternator tested so we can confirm nothing is wrong there.

Thanks to all who responded and gave helpful direction.

Talked to my daughter the other day and she said the ABS lights are all turned off and the AC is working again, though occasionally blows hot air. She has not had a chance to check on the connector(nursing school graduation coming up).

I really hate intermittent electrical issues, especially when the RR is 300 miles away. We have a trusted indie Land Rover mechanic where she is, so I think I'm going to have it dropped off there. He has several P38s sitting in the yard, so I may see if he can swap in a HVAC control face with a working LCD screen while he's working on the other issues.

Gilbertd wrote:

Not memorized, I just keep it open so I can quickly look stuff up. Ignition switched power to the HEVAC comes from a connector on the back of the BeCM that can be accessed by lifting the carpet in the RH rear passenger footwell (it's the only connector on the back so not difficult to find). That connector can overheat and lose power. On a pre-99 car that same feed also goes to the radio and the brake light switch and I was wondering if a loss of power to the brake light switch would cause an ABS error but it appears that on a 2000 they don't use the same feed (so that is that theory out of the window....). But, there is a feed from the ABS system to the HEVAC (no idea why) so it is possible that an ABS fault could shut down the HEVAC.

Thanks. I'll see if she can check the connector.

romanrob wrote:

Not enough juice on the battery...I only saw the vanishing hevac once and that was the battery collapsing... Is the alternator charging properly? Have you uprated the VR?

My only experience with a weak battery gave the gearbox error and the, I think, if memory serves me well, the transmission went into limp mode. New battery fixed those issues.

I'll definitely have the battery checked, though.

Aragorn wrote:

bad fuse box perhaps?

Seems like a lot of unrelated circuits losing power at the same time?

this was my thought, as well. the losses do all seem unrelated.

karlos01 wrote:

what year and engine is your p38 ?
and where are you based someone on here might be near to her and could do diagnostic tests

the srs light could be loose wire under the seat

some times the lights come on when battery voltage is low

or could be faulty abs sensor

it's a 2000 with the Bosch engine management.
she's in Oklahoma. we have a good indie Land Rover mechanic there. but i was hoping there might be a simple fix to save the trip to him.

My daughter has the P38 250 miles away at school. She called today because as she was driving on the highway the ABS, TC, Brake and SRS lights came on and then the AC shut off
and the lights to the HVAC unit all turned off.

When she was able to stop, she turned off and restarted the RR. Again ABS, TC, Brake, and SRS lights came on. The AC came on then shut off as did all the HVAC display lights.

At least it's all consistent. Should I be looking at relays or fuses? I'll be relaying any info from here to her via the phone/F@ceTime. She's not afraid to get her hands dirty but has limited experience with this Land Rover.

The SRS might be unrelated as it was turning on and off prior to me dropping off the P38 a month ago. I thought I had fixed it, but perhaps not.

Thanks in advance.

all seems to be working as it should.

I'll update this thread later if needed.

Thanks to everyone who pointed me in the right directions.

shop called yesterday and said they found a burnt relay in engine bay fuse panel. replaced it and all is working as it should be.

i'm hoping it was just age that caused the burnt relay.

Techs at the shop are saying that the left side motor is not working. They think there is a short somewhere because they can manually turn on the blower motor. Assuming they are correct, does this point to a HVAC control unit?

Gilbertd wrote:

First guess was correct, left and right. However, the ducts from each come to the heater matrix and then split again after it. If only one blower is working the airflow from the working one gets to the heater matrix and has a choice of which way to go, through the matrix or across to the other side and out where the air would normally come in. That will result in not a lot of air out of the vents.

Thanks, Richard.

I am getting much weaker air from the face vents and the windscreen vents even when only the face vents or the defrost is selected. The foot well blows at full force.

This leads me to believe the shop that replaced the blend motors did not reconnect the duct work properly.

thanks for all the info.

looking at the P38 Workshop Manual I'm seeing two blower motors. One on the right and one on the left.

The Manual doesn't clearly state which blower motor does what, unless of course, I just overlooked it. If anyone knows the page number that does spell out what each one does off the top of their head, feel free to share it.

My assumption is that the right hand blower handles air on the right hand side and the left hand blower handles air on the left side of the cabin. Is this correct?

Or does one blower handle the footwells and the other handle the face level vents and windscreen vents?

I just had my blend motors on my NAS spec 2000 P38 replaced by a reputable shop. I have two concerns.

The first is hopefully and easy fix. The front, far left vent will not open. The louvers all work fine. It is the door that is open and closed by the dial. Can I just pull the vent cover off and open the door? What might be causing this?

The second relates to the force of the air coming from the upper center dash vents. It feels a bit anemic especially compared to the footwell vents. It's been so long since I had upper vents that worked on this Rover that I've forgotten how it should feel. How strongly should the air be blowing out from those upper vents? I know that's a vague question but currently it just feels week.

Thanks,

i'm getting ready to replace the shocks on my 2000 P38.

is this as straight forward as it seems? just follow the Rave and done?

i've replaced the shocks on my Discoverys, so familiar with the procedure. but i just want to make sure there are no surprises the P38 will throw at me.

i was finally able to climb under the Range Rover and look for brake fluid leaks.

i checked all four corners and couldn't find any wet spots or other indications of damaged or split lines or hoses.

all the flexible lines looked good and all the hard lines were rust free and dry.

i took a quick look in the engine bay and couldn't see any leaks there either.

i'm a bit stumped at this point and not entirely confident there isn't a slow leak somewhere that i'm just not seeing.

anything obvious i am missing?