book on hevac on hse 4.6 1995

hi,

can the book come on when the air con simply needs recharging. i can get heat so i assume its not the blend motors. i cannot get ice cold air though so i am asuming i need a recharge. also when light is on on the ac button, is it actually on or off.

i have only recently got this vehicle so am still playing with the buttons so i am unsure.

thanks

Yes it can, light on = a/c off.

thanks ant,

so when you start up the air con is automatically on?

No, if you press the switch and the light stays on, the A/C is off. If you start the car and the temp is set to low then the light will flash for about 5 seconds letting you know that the temp you have chosen will not be reached without switching it on. After the flashing thi light will stay on unless you press it again.

i will go have a check.

ok, i am confused even more now, when i turn the air con off ( button lit ) with the temp at 28, it blows out cold air ( not icy cold ). when i turn the air con on with the temp still at 28 it blows out hot air and when i play around a bit the book comes on.

any ideas please/

It either needs gassing or your condensor is leaking or your aicon isn't kicking in....do a search on it

i can hear it kicking in because the idle either drops or increase. if the condenser is
leaking can this be repaired with an air con service/recharge

Leaky condensors are best repaired with new ones, not bodge-type "fixes". It sounds though as if perhaps one of the blends is playing up or possibly even the HEVAC console itself. Try cycling through all the blends and checking if the direction of airflow is correct - ie that they blow through the correct vents when you direct to screen / top / feet etc.

You could also go to one of these kwik-fit type places - a lot of these franchises now have machines that check pressure in the aircon system, exchange gas, add PAG oil, and put dye in the system to check for leaks - takes about an hour and costs around £50 - £70.

Usually (but not always) the dreaded open book means a duff blend motor or a faulty HEVAC front unit - unless you have the knowledge or fast learning ability, there are people out there who are very good at diagnosing all the other issues-blends are an expensive repair if you try a stealer, but I've used this chap who I think is very good, he travels around the Midlands:

Jason Partridge
07903077948

all the air travels through the vents as they should but why no heat when the air con is off and heat when the air con is on

if i have it plugged in and tested by test book, will it show up exactly what the faults
are? and if the unit is naff?

if i have the car plugged in and tested will testbook show the true fault codes and will it say the unit is naff if it is naff?

hunterandthehunted said:

if i have the car plugged in and tested will testbook show the true fault codes and will it say the unit is naff if it is naff?

Click to expand...

Most of the faults/problems can be sorted yourself with a bit of patience and time.

Read The air con section here:

Range Rover P38/4.0/4.6 Common Problems and Fixes


hth

zzr

I had mine on for a while, didnt pay attention to it much as everything worked fine. After I serviced it, it the book went away. Only thing I can think of that would have helped was to change the pollen filters. Bit odd if you ask me.

bit of progress thanks hammy,

the pollen filters were black so i removed them and now i have got the heat whether the air con is on or not which is something. obviously i will replace them as soon as.

one thing i have noted is that the 2 fans in front of the rad don't work whatever i do. now are these supposed to kick in when the air con is on?

i think i need to have a diagnostic of some kind on the air con system so i know what to replace. does anybody know of a good reliable place in norwich or would this be a stealer job.

thanks

Your problem is almost certainly a leaky condensor on the aircon, a common problem. It was easy to diagnose on mine as there was dye in the refrigerant and I could see the stains from the leaks. You can get a new condensor on Ebay for about £75 and fit it yourself, it's not difficult.
Otherwise get a leak test done first if you cannot see staining on the condensor.
The 2 fans only come on when called for by the aircon or if the engine temperature is too high.

thanks,

is there a step by step guide anywhere?

From the symptoms you described ie blowing hot when aircon is on, I think the temperature blend motor might have gone on one side - does it blow hot both sides or just passenger/drivers side? , aside from any condensor leaks you may have as well. Diagnostics from a stealer costs about £80 but several independents have Rovercom / Faultmate / Testbook units and charge much less. Maybe have a pressure test and a diagnostic before splashing out any more money, just to identify the actual problem areas.

it blows hot all over as it should when temp on hot whether air con on or not. when i turn down to 16 the temp change to cooler air, but not air con cool ( just temp of any normal system without air con ) this is when the book comes on the hevac.

hunterandthehunted said:

it blows hot all over as it should when temp on hot whether air con on or not. when i turn down to 16 the temp change to cooler air, but not air con cool ( just temp of any normal system without air con ) this is when the book comes on the hevac.

Click to expand...

Maybe not the temp blends then, but I'd start by getting a pressure test / regas/ dye and then a diagnostic if the fault doesn't clear. Maybe just the lack of gas, due to a leaky condensor, fairly easy to fix and cheap by RR standards - under £100 to change a condensor if you do it yourself, and around £50 for regassing etc.