Range Rover heater

[graham]

Hope someone can help my mates RR with climate control. The heater doesn't seems to get hot the pipes going into the bulk head feel hot.

Any ideas :(

[aldenplanthire]

hi

i had same problem on my dse, turned out to be the blend motors,

does one side get slightly warmer than the other or is it cold air all the time

[graham]

Sorry just seen your reply, cold both sides.

[aldenplanthire]

In My Case It Was The Rh Heater Distribution Vent Flap Locked In Cold Position Due To A Inoperative Servo Motor (blend Motor)
Other Possible Causes Could Be
Engine Running Cold
Heater Pipes Blocked
Blown Heating And Ventilation System Fuse
As Far As The Blend Motors Are Concerned Without The Landrover Diagnostic Equip It Is Difficult To Pin Point The Exact Problem Im Afraid

[zcar]

Is the book icon present on the panel???

Nick

[Cocky Lil Guy]

Just change the HeVac! Its the most expensive problem on the heating/air con of a rr! And controls absolutly everything, its most likely that. Its easy to replace, i could guide you through it if you got a HeVac if you wanted!

[aldenplanthire]

this may be of interest



This procedure has been developed on a 1995 New Shape RR 2.5DT with Climate Control. You know how it is, driving along, all is well with the world, when you spot the little book symbol in the Air Con temperature display. After the initial panic has died down, you read the handbook, there it is, page 73, "Take me to your Dealer" Gulp. Visit once for the diagnostic test, a minimum of half an hours labour cost. Then visit again for the repair.

If you could test the system yourself, you could save the first cost, and you can phone up for a repair quote without having to visit. Perhaps ring round for alternative quotes. Possibly, just possibly, YOU can fix the problem! (The quoted repair cost can be a strong motivator). Faults and cures are another article, first you have to find out what is wrong.

This is really a straight forward functional test. You should have a small torch, possibly reading glasses if you use them, and maybe a straightened paper clip. Technical isn't it?
When finished you will have tested :-
the Air Con compressor (and chilled air output),
the in-car temperature sensor,
the solar gain sensor,
both blower motors,
the distribution flaps/motor,
the recirculation flaps,
and the blend flaps that mix hot and cold air.

For these first two checks, the car and engine can be hot or cold.
Identify the in-car temperature sensor, this is behind the grill positioned just below the clock. There is only one sensor.
Peer through the grill with the torch, and glasses if required. Look sideways, there is a small fan, like a drum with blades on the outside, not like a propeller / radiator fan. Without starting the engine, switch the ignition on, you should just hear the fan running, and be able to see the blur of the blades moving. As a last resort, gently, GENTLY, probe sideways through the grill with the end of the paper clip. Withdraw when it vibrates!
The fan is there to improve the effectiveness of the sensor, by drawing air across it. Fan failure won't stop the system working, but the control of the internal temperature will be poor. The heat will stay on too long, or off too long, leading to wide variations from the set temperature.

Recirculation flaps.
You need quiet for this. Turn the ignition on, but without the engine running. Wait for the brake pressurisation motor to stop running (30 to 45 seconds). Turn the Fan Speed (blower motors) down to minimum.
Operate the recirculation control and listen for the flaps moving. The noise will only last for 5 seconds or so. There is one flap on each blower motor. The blower motors are underneath the dashboard, above your kness rather than ankles, but against the outside of the car. The flap motors are very quiet. The flaps will move again when the recirculation control is restored. Repeat as required.
If you cannot hear them, you will have to test them while the car is moving. When the car is warm, switch the recirculation control on. The car will become noticeably stuffy within about 5 minutes. Switch recirculation off, and the atmosphere will clear.

Now have the engine at normal operating temperature, ticking over, with the A/C switched on.
I assume the book symbol is still showing. The system will self check every time the vehicle is restarted.
If the fault disappears, so will the symbol.
Compressor / chilled air faults will be self evident throughout these tests, no Cold Air.
If this is apparent, open the bonnet, and with the engine running, have someone switch the A/C on and off. There will be an audible click from the Compressor as the clutch engages. Placement of the compressor varies from engine to engine.
Remember, in the absence of chilled air, either through a faulty system, or because the A/C is switched off, the system will substitute external air, at the ambient temperature. In some parts of the world (rarely in the UK) this can be hot. Thus sometimes "cold" air is hot.

Distribution Flaps.
Set both Driver and Passenger temperatures to 16.
Turn the Fan up to get a decent airflow, that is half or threequarter speed.
Using the manual buttons, direct the air towards the footwells. Check with your hand that the airflow is of similar strength and temperature.
Note any side to side differences.
The air issues from triangular holes on the sides of the transmission tunnel above your ankles.
Check there is no air flow from the Facia or Screen outlets.
Use the buttons again and divert the air towards the facia vents, remenber to have them open, check again for flow and temperature.
It takes a few seconds for the Distribution flaps to move to the new position.
Check there is no flow from the non selected outlets (Footwell and Screen).
Use the buttons again and divert the air to the screen, check again for flow and temperature, especially any side to side differences.
Assuming the airflow moved correctly from footwell to facia to screen, and DID NOT appear from any outlets that were not selected at the time, you have proved the Distribution flap / Motor works.

Blower Fans.
With the air issuing from whichever vents you find most convenient to monitor, turn the Fan speed up and down.
Check the air flow varies on both sides of the car. There are two Blower motors, one Left, one Right. They should both change together as you adjust the speed.
Assuming they do, you have just proved the blower fans work. Leave them on half or threequarter speed.

Blend Flaps.
With the air issuing from whichever vents you find most convenient to test, raise the Drivers side temperature to 22, wait a few seconds, can you feel a temperature difference when comparing Driver side air ouput to Passenger side air ouput?
Raise the Drivers side to 28, there should be an obvious difference in temperature.
If the Drivers side airflow temperature has not changed, the Driver side blend flap is faulty.

Reset the Driver side temperature to 16, then repeat the test, varying the Passenger side temperature.
If the Passenger side airflow temperature does not change, the Passenger side blend flap is faulty.

Solar Gain.
The solar gain sensor is a black button on the centre top of the dashboard, near the windscreen (near the Alarm LED).
With engine ticking over, and A/C on, switch it to AUTO mode. Adjust both temperatures to a medium/ low setting, (16 to 22) and let the system stabilise, with the blowers running but not too fast. Shine a bright torch on the Solar Gain sensor, it may take 30 seconds or so, but you will hear the system adjust to compensate for the additional heat, probably by increasing the fan speed. Remove the torch and the system will adjust back, give it a minute or so.
If the system compensated for the additional heat, the solar gain sensor works.

In car temperature sensor.
This is situated behind the grill below the clock.
With the system set as for Solar gain, heat up the Cigar Lighter, and hold the hot end in front of the grill, but not close enough to melt the plastic!
1 to 2 cm should be fine.
If the system compensates for the additional heat, the in-car sensor works.

Additional information.
When on Auto, if a number is showing in the temperature setting, the system will control the position of the blend flaps, dependant on internal temperature, external air temperature, etc.
If you adjust the setting to LO, the blend flaps are forced to the end of their range, to deliver ONLY cold air, whatever the actual temperature is, inside or outside.
Remember Cold air will be hot if you are in a hot climate and the A/C is switched off.
If you adjust the setting to HI, the blend flaps are forced to the end of their range, to deliver ONLY heated air, whatever the actual temperature is, inside or outside.

That's it, you should now know what functionality is absent, and can start checking repair costs, or read the (future) article on known faults, repairs and workarounds.

[fisha]

to the above test which was put together by David Sparkes and feedback the results.

changing the HEVAC is about the last thing i would do. Its most often the blend motors that stick ( which are changed without needing to change the HEVAC )

[graham]

Thanks all, have emailed link to this thread.

Thanks

Graham

[graham]

My mate Jim has printed off your replies and asked me to pass on his thanks for all your help. :)

[Paul K]

Excellent post! My HEVAC system started playing up last year-Icouldn'tread the green numbers. Land Rover replaced the unitunderwarranty,then it started blowing hard , shutting down then blowinghardagain. I had them look at it, and it went to blowing hard allthetime.Now it's back to blow like crazy, shut down, then blow likecrazyagain.This is onAuto with both sides at 70 degrees Farenheit. Iseem toremember the old unit would blow until it got the cabin up totemp,thenback off. The little fan under the clock is running. Anyideas?

Cheers,

Paul.