smurf

Flickering dash lights suggests a problem with the 12V system. Obviously you have a 12V battery, but there is no alternator in the traditional sense on the hybrid. The battery is charged, and the 12V system is powered, by a DC to DC converter from the hybrid battery. Unlike a traditional 12V setup from an alternator, this means the 12V system has a constant voltage with the ignition on. If it is anything like mine, this will be 13.9V at all times. The best way to be able to see what is going on is with techstream. If you can put a windows virtual machine on your Mac you can then put techstream on it. Failing that, an old laptop will run techstream easily. You will also need an mvci cable to interface between the laptop and the car.

I've heard a couple of anecdotal stories about a Cambridge based hybrid specialist, and they wouldn't be on my list of prospective garages if I had a hybrid fault. Don't know if it is the same people, but there can't be too many hybrid specialists around there. Options are limited, as you have no doubt already discovered. I'd be going with the best expertise available rather than local garages willing to have a go at your expense. You might find your breakdown cover will transport the car to a location of your choice. If you are on Facebook you could try asking on this group if there is anyone nearer to you that could help https://facebook.com/groups/584860908755825/

When you say it had a differential changed, do you know exactly what was changed? The gearbox is quite a complex and unusual piece of equipment, and I'm surprised you found a garage willing to replace a component of it. You need to take it to a hybrid specialist who understands Alphards and has the correct diagnostic equipment or you will waste more time and money with garages taking a guess after two days, or RAC mechanics that think the car has a dodgy 12V alternator (it doesn't have a 12V alternator). There is a hybrid specialist in the Exeter that travels https://www.hybridrepairservice.co.uk/ Another alternative is this guy in Wigan that seems well regarded. You would have to get the car trailered up there though. https://www.facebook.com/Vjkomix

I own a gen 1 hybrid, which I am happy with, but from an engineering standpoint the gen 2 hybrid is the better of the two, and not just because they are newer. As you were looking at a gen 2 I just wanted to highlight they are different and if you go googling you will no doubt find horror stories than aren't applicable to the gen 2.

The gen 1 and gen 2 hybrids are completely different beasts, so do bear that in mind when researching whether to buy one or not. Some simplistic differences are the gen 1 uses the original Toyota Hybrid System, gen 2 uses Hybrid Synergy Drive. Gen 2 has a more powerful engine, is more economical, and can go faster on just electric drive. The gen 1 has a CVT gearbox with a belt drive, but the gen 2 has a CVT like gearbox with epycyclic gears. Both types contain a motor/generator within the gearbox so they are not interchangeable with non hybrid gearboxes.

You will quickly drain a battery with a heater. For example, if we assume it was possible to extract all the energy out of a 100ah battery, it only holds 1.2kWh of energy. It isn't actually possible to totally drain a lead acid battery of all its energy without turning it into a door stop, so it would be far less than this. You might be lucky to get half of that it you don't want to wreck your battery.

I'd be careful buying items like spark plugs from eBay. Counterfeit parts are rife. Buy them from a reputable place.

I think this was ET's latest attempt to phone home. Open the box and take a photo and we can stop the guess work 😀.

Details here of how I did it.... https://uk.alphardclub.com/forums/topic/7919-awning-rail/#comment-28307

Some modern cars, and I know VAG cars need this, have to have information from the battery programmed into the ECU when the battery is changed. I haven't heard that a 2010 Toyota would need this. If you have a working alternator (which it sounds like you do), no significant parasitic drain and your battery volts is dropping below 12V after a couple days, then your battery is on it last legs. A bit of cold weather might just kill it off. I'd just replace it with whatever the recommended replacement battery is. You could buy an increased capacity battery if you like, but there is no need if you have no actual use for the increased capacity, such as leaving it for long periods unused.

It is indicating fault with something related to the hybrid system. It could be simple, it could be expensive. You need the codes read to find out what exactly.

You may have one already, or might not wish to confirm or deny it on a public forum, but it may be worth looking into the discounts available for having a tracker installed.

As it has now got me really interested, I thought I probably know exactly where that is. 5 minutes later and I have my hands on it. My rock and roll bed is on rails so I can move it forward out of the way, but this really is the easiest job in the world to swap out.

I have had a quick look, as it piqued my interest, and the part appears to be shared with the Prius of the same era. Consequently, it is available in plentiful numbers and quite cheap (under £50) second hand. From what I can find online, the part is 89680 in the image, which appears to show it is located in the rear on the passenger side. Depending on what needs stripping out to get to it, the rock and roll bed might have to be removed, but other than that it looks like a simple swap. I can't see why it would be nearly £1500, but there might be an explanation.

What is the brake capacitor? Not a component I have ever heard of.

That is really good compared to my experience of 35 mpg on the motorway and I tend to stick to 60mph on cruise. I think I need to get my act together and do a refresh on my battery to see if that improves it. Sadly, as I don't have the original stereo fitted I have no idea how well the battery is performing.

What problem are you trying to solve? If I leave the lights on and open the door I get a warning buzzer.

Sadly, Watling closed down a year or two ago. I think the only option now for a gen 1 is the PCT towbar mentioned above. Not sure about newer models.

@PaulE This will help you find it and fix it.

If you turn the temperature all the way to maximum and all the way to minimum you should be able to hear it moving the flaps to either end of its range. You might be able to see some of the mechanism moving as well.

Is yours a hybrid? If so, the 12V battery has no involvement in the stop/start system or regenerative braking and it has a much easier life as all it is doing is powering up the 12V systems. The engine is started with the hybrid battery and regenerative braking power goes back into the hybrid battery.

https://www.ebay.co.uk/itm/116331772408?mkcid=16&mkevt=1&mkrid=711-127632-2357-0&ssspo=BbXbpzRoRby&sssrc=4429486&ssuid=ql8_keC9RJe&var=&widget_ver=artemis&media=COPY

There is no official way of disabling the passenger airbag that I have been able to find. If you are handy with electrics and happy to research, it would be possible to install a switch into the circuit to the airbag, but it can't just switch out the loop as it will put on the airbag light. It needs to disconnect the airbag and switch in a resistor so that the ECU thinks the airbag is still there. As to the value of the resistor required, I've no idea, so that is where the research is needed.

Is the temperature control flap moving? This video will help to locate it

It is strange that Adrian Flux said they didn't know what an Alphard is as many owners, myself included, are insured with them.