I understand that our cars are very complex, and something as innocuous as a heater system has algorithms and electrickery behind its operation.

For the last month, the FF had hardly moved, as I was away for 3 weeks, and I had used the Defender to prevent its battery going flat. However I was getting the "Battery Low - Please start engine" message in the FF.

For a couple of short journeys this week, although the engine got up to temp and I'd normally expect it to blow warm swiftly, there was no air coming out, and I couldn't force it by going manual.

So, is there a rule of some description that looks at the battery voltage, amount of recent charge, likely charge, and decides whether or not to use power on the climate system or not?

I took a long journey today and after a while it all kicked in and warmed the cabin as normal. I've had this before in other L322s too.

???? Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

exactly the same issue with me this morning. FF stood unused for 10 days in the cold. First time ever had the low batt warning. short trip to the office and the blower only commenced action after about 2 miles - so yep I'd say it wont heat until the alternator has has chance to do something.  405 AB exec seats Baltic and Cirrus
93 RR Classic efi

Remember it's easier to get forgiveness than permission!

Gone in order:
4.4 TDV8 SE - gone to a good home
93 Classic hard dash Plymouth Blue
03 L322 Oslo Blue
2000 Disco TD5 ES Epsom Green
98 P38 Rioja Red
89 Classic Cairngorm Brown

Mine has a tip top battery but doesn't heat for at least 2-3 miles. I had always thought it was to do with the system not wanting to blow cold air in to the cabin. i.e. it waits until its really well warmed up before allowing the blowers to operate. Even though the petrol engine warms up quite quickly the heater seems to take much longer. 2012 5.0L S/C
Previous:
3.6 TDV8
4.4 HSE
P38 4.6 HSE
Classic 3.9
90 County
Series3 Lightweight

Yes the car wants to charge the battery first Adam... Clever old things "aint um”

Ta Craig and others

Glad I am not imagining things. Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

I think the ECU has some kind of priority where it distributes its power until the battery is at certain voltage. I've noticed things like the heated rear screen will not come on, whereas the front screen will.

Also if you check alternator voltage output immediately after starting the car from cold, you don't get 14.4 V - more like 12.25...... After a couple of minutes it gets to 14.4, I have read somewhere that this is called "smart charging" and helps preserve battery life.

Yes Wealy, its all to do with the conversion to AGM batteries sir...

Adam... Craig is talking a pack of lies, your FF is seriously broken and will never be the same again, I will do you a big favour and buy it off you for £5000.....



Craig, will you stop this, how will I ever get a cheap S/C..??? Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Add a zero and it's yours! Discovery 4 HSE
1998 110 TUM HS FFR Hard Top XD WOLF
1982 Series 3 Hard Top

*Gone:L462 D5 HSE LUX, L663 Defender 110 HSE, Discovery 3 HSE, 2014MY Range Rover Sport 5.0 Supercharged AB Dynamic; L405 Exec Vogue SE 4.4, 5.0 Supercharged Autobiography, Defender TDCi XS CSW, Defender TD5 HT, Vogue SE TDV8, Vogue TD6, RRSport SC 4.2V8, Classic 3.9 Vogue Auto, Land Rover Series 3 SWB

£05000........  Pete
__________________________________________________
2014 L405 Autobiography SDV8 4.4 Loire Blue Ebony interior
2012 L322 Autobiography 5.0 Supercharged Ipanema Sand Sold
2011 L322 Vogue SE 4.4 TDV8 Baltic Blue. Sold
2002 L322 Vogue 4.4 V8 Epson Green (Fatty Offroader) Sold
-Click for Project Fatty off roader-

Love it

Cam-Tech-Craig wrote:

Yes Wealy, its all to do with the conversion to AGM batteries sir...

I thought it was mainly to do with reducing emissions. Basically the batteries are nice large reservoirs of power so can survive a few minutes without being recharged. It gives the engine time to warm up, the moment the car detects you braking it loads up the alternator more so that rather than waste power in heating the brake discs you recover some of that.

Simple regenerative braking

Similarly when you accelerate hard it can remove load from the engine allowing more energy to be used accelerating the car up to speed and thus make it more efficient.

Years ago when these started coming out BMW and Volvo reckoned they could get ~3% increase in fuel economy simply by doing these tricks. The research and projects I did at the time showed that this was perfectly realisable. Ed