smurf

I assume the electrician has not looked at the schematics, and is only considering the implementation of canbus in its most modern form where nearly everything on a car is directly on the canbus. A 2007 Alphard has canbus and MCX to the dash. The schematic in the manual appears shows the speed signal to the dash is provided over canbus. The sensor is not connected to canbus, it is connected to one of the ECMs that will have a canbus connection. If the electrician has checked the canbus speed chip why do they think the car doesn't have canbus? I'd be disconnecting the canbus chip from the dash and see if the problem goes away.

What year is your car?

I've sent you a PM James, with some info about a manual.

The speed sensor will go through an ECU. There will be a canbus connection to the dash from the various ECUs, which brings me to my question. How has your car been converted to read mph? Has it had a dash overlay, or has it had a canbus chip installed? The canbus chips can cause all sorts of issues when they play up. If you aren't sure, an overlay will likely have mph and kph numbers on, but if a canbus chip has been used it will be just a single scale.

Powering an electric heater from a battery is not really a viable option. I just looked at the stats of a Bluetti 1800W, and it only has a little over 1100Whr of power, which is just over 2 hours running a 500W heater. A diesel heater would be better for heating, especially if you are considering going off grid in winter, and a small gas stove might be simpler for boiling water.

At least one working rear fog light in the centre or to the right of the vehicle is the MOT requirement. Front fog lights aren't a testable item. Not sure why a wing would need taking off for a rear fog lamp repair?

An alternator is another name for an AC generator. When applied to cars, what most people are talking about is the small generator ultimately responsible for providing the 12V required to charge the battery and power the 12V systems. The Alphard hybrid does have an alternator, but it is not powering the 12V system. It is actually a starter/generator that is used to start the engine under certain conditions, and I believe it acts as a generator when needed to help charge the hybrid battery at tickover.

Have you checked the usual petrol engine problem causers? A dirty throttle body seems to be a bit of a feature of Toyota's and can give the problems you have, MAF sensors also get dirty and cause running issues, there could be ignition problems such as spark plugs or coil packs.

There is no alternator on the hybrid. There is a DC-DC converter that (on my 2003 hybrid) outputs 13.9V when the ignition is on, with the supply coming from the hybrid battery. 13.6V should be absolutely fine to keep everything powered up, but it could be a indicator of gremlins at play. Is your OBD scanner compatible with JOBD? Even if it is, it might be worth getting techstream and a minivci cable as you could check live data and see what is going on. It also might pick up codes that a generic reader has missed.

I'm surprised it didn't come spring loaded so it can't flap about? A quick Google search did throw up plenty of spring loaded EHU sockets, so maybe a change might be the simplest solution?

Those conditions read to me that they only apply when they are stated in your insurance schedule. If they aren't in the schedule, then they don't apply. I'd double check with the insurer.

The factory fitted immobiliser won't be Thatcham approved. I'm insured with Caravan Guard. They take a lot of details, but it means nothing is left to chance. The only downside with them is that it does have to a professional conversion and they do ask who did it. If it isn't on their list they won't offer cover. I can't remember the cost off the top of my head, but it was very reasonable.

You'll need to use Toyota Techstream to do it yourself.

The springs and shock absorbers aren't arranged in a strut, they are separately mounted and changing one doesn't involve the other, but obviously it will do no harm to change them.

The lack of gas does need resolving. Knowing what pre-charge pressure it should be set to will be a challenge as it doesn't appear to be published anywhere. Contacting Tein ú in in Japan might the best way to find out. From the photos I've seen there appears to be no pressure sensors fitted to the gas side of the suspension, so the controller wouldn't have a clue what the pressure is. I would expect low tank pressure to be related to the hydraulic pump. It doesn't look like the system holds much of a reservoir of oil, so if the bladders are empty of gas then that is more volume to be filled with oil before it can begin to build pressure, and if there isn't much spare oil in the system it just isn't going to work. Look for hydraulic maintenance specialists near you. The chances are that they will have the gear to recharge accumilators and it should be easy for them to charge up your suspension, so long as they know what pressure they are aiming for.