Category Archives: Electrical

Yet more wiring !

Isolation Switches

Isolation Switches

It seems at times that the amount of wiring in the 90 just keeps going up and up and up ! This last weekend I’ve had the dash apart again, hopefully for the last time before it ships…

I wanted to add a couple of isolation switches both for safety and also to ensure that the batteries will make it to the other side without being discharged. I wanted to add an isolator for each battery so they could be isolated individually. If nothing else this means I can leave the auxiliary battery disconnected so if the main battery gets left on during shipping we can jump start it from the auxiliary battery. Positioning the switches so they are accessible from both seats and at the same time reduce the risk of them being accidentally switched off took some thinking about and in the end we settles for a position next to the passenger seat. The main battery switch is an FIA type which has the extra contacts that I’ve wired in so that the switch will also kill the engine if turned off with the engine running.

iPad mount and map light

iPad mount and map light

I have rewired the switches for the spotlights and the rear work lights – the rear work lights were connected to a Carling switch on the dash and the spotlights to the Land Rover spotlight switch. This was OK but didn’t give too many options for the spotlights and, as they are LEDs and can be left on for long periods without draining the battery, I wanted a switch that would allow them to be turned off, on only with main beam and on independently. To achieve this I changed them around using a Carling switch for the spots and the Land Rover dash switch for the rear working lights.

With the Dash apart I changed the iPad RAM mount from the seat mounting type to a universal mount on the dash. The seat mount is OK but tends to wobble around all over the place when you’re crossing rough ground, so much so you have to lock the rotation on the iPad. The dash mount takes up less room and will stop the annoying wobbling !


Australian CB Radio

I also added an LED interior light for the passenger area that works in addition to the factory interior lights and fitted the mount for the UHF radio (Australian CB radio), connected up the power lead for the radio and the aerial lead. I also got around to fitting the map light to the top of the dash. All in all a busy few days and lots of jobs “ticked off” the list in the process 🙂


Mounted and covered !

It’s been a couple of weeks since the last update and with about 5 weeks to go before the shipping date it’s been a week of checking and re-checking what needs doing still and that we are still on track both in time and budget. Fortunately, so far, it’s looking pretty good, let’s hope it stays that way 🙂

Hi-Lift Jack in position The Hi-Lift mount is done, painted and fitted, I got some M10 ring nuts as an impulse buy while perusing an online nut and bolt shop (as you do) and it turns out they are perfect as a way of securing the Hi-Lift to the mount and providing extra tie down points. With the design I eventually came up with the Jack is secured with a single one of these nuts and is held securely with no rattling. A second nut can be added to the foot for additional security but isn’t really needed.

ECU wiring coverAnother in the long list of jobs I’ve been meaning to get around to was to make a cover for the ECU, or at least a cover for the wiring going into the ECU. Being behind the seat we’ll probably end up stuffing clothes, water, snacks and who knows what else behind the seats and there was always a danger that this would stress a wire or separate a plug so it needed to be a bit more robust.

in between rain showers and F1 coverage I ended up making 3 different covers, the first out of cardboard to use as a template, the second out of aluminium based on the template and the third because the first two didn’t quite fit right ! Third time lucky though and I’m quite pleased with the result, not too intrusive and covers all the important bits while allowing access to the fuse box and relays.

One other thing we’ve “ticked off” this week is the MOT test, the MOT is/was due to expire in March 2014 which isn’t ideal so we’ve taken it for an MOT 5 months early so it will be fully UK road legal throughout the trip (one of the requirements for use in Australia as a foreign vehicle). As expected (although always a relief !) it passed without any problems/advisories.


The countdown has started

IMG_0383It’s been a busy few months but things are really starting to fall into place now with the official agreement from work for me to take the time off etc… The shipping date is more or less finalised so I now have a deadline to work to and that in itself has certainly focussed our attention on what still needs to be done between now and then !

Near the top of the list is the fuel and battery monitor as that will play a key part in the trip, giving a more accurate view of the current fuel status across the two tanks than we could hope to get from the standard gauge. The wiring for the unit is now completed in the vehicle, along with a bypass plug that allows the unit to be removed and the normal fuel gauge to work as normal. This should give some redundancy should the unit fail for some reason.

The monitor is on the second design and is now full functioning with just a few software tweaks needed and some calibration of the fuel levels. The auxilliary tank has been calibrated now and I just need to put the values into the software, the main tank is next to calibrate. I’ve calibrated the tank/sender in 5 litre steps so we should have a reasonable idea of the remaining fuel at any time if the sender unit stays consistent. I still need to decide exactly where the lcd display will be mounted, a 3D printer would be very useful right now to make a custom pod for it !

While calibrating the auxiliary tank we managed to get 57 litres into it before it started to overflow, 55 is probably a more sensible amount to put in but it shows how much you can get in, using a 5 litre jug.

Fuel and battery monitor goes beta

20130621-131829.jpgThe fuel and battery monitoring system is now ready for the next stage, transferring the design from a prototyping board to a custom board design. The new 2×8 character display seems to be clear enough and is small enough to mount in the dashboard somewhere. I’ll add/maintain support for in situ programming of the PIC chip so I can tweak the calibration and display functions as required.
Hopefully I’ll get the PCB Design finished and the board etched this evening.
The module itself has suffered from a bit of bloat ware during the design process but hopefully it’s now got all the hardware features it needs to support and anything beyond that can be tweaked in the software. Once it’s all finalised I’ll create a page with the design for anyone that wants something similar.

Engine monitoring system


I started to fit the sensors for the EMS today. The engine monitoring system I’ve chosen is a South African design and it should give us an early warning of any problems developing with the engine.
The EMS will monitor and display:

  • Coolant temperature
  • Coolant Level
  • Exhaust Gas Temperature
  • Oil Pressure
  • Battery voltage
  • Transfer box temperature

20130620-105003.jpgThe gauge itself replaces the standard temperature gauge and allows alarm levels to be set for any of the items it is monitoring with both a visual and audible alarm.
As I had to drain the coolant to fit the coolant temp sender I also replaced the thermostat – one of those jobs that’s been on the “to do” list for a while now.
The oil pressure sender was the only one that caused me some grief. Partly this was because the kit seemed to have the wrong adaptor with it. I had a suitable adaptor in the garage so I managed to get around that particular problem. The bracket that the sender comes with though is a bit small for it’s intended use and that, combined with limited space between the cylinder head and the air filter box made the job a real PITA.
Anyway, the sensors are in and the wiring made up to the bulkhead so just the gauge to fit and the wires to join up and it’s just about done.

Fuel revisited, again !

Having had some time to go over our experiences of the last week or so it seems that yet more “tweaks” will need to be made to the fuel system although, thankfully, nothing too painful.

The good news was that with the 90 fully loaded in “overland” mode the new MAF sensor I fitted just before we left has brought the fuel consumption back into the realms of “reasonable”. With a mix of motorway, dual carriageway, narrow B roads and some town driving we were getting just above 24MPG during the trip. Having the twin tanks really let us push the limits on range without having to worry about running out of fuel. The main tank gave us a range of just over 430 miles without running out – I’d have let it run out just to see how far we could have got on it but we were on the motorway at the time and I didn’t fancy having the engine stop in that environment. We haven’t taken the front tank more than 200 miles yet but it’s looking as if the combined range is going to be in the region of 750 miles.

The only problem we’ve encountered is that the fuel gauge isn’t directly connected to the sender on the TD5, instead it’s controlled by the Speedo… really, it is ! The speedo prevents large changes in the gauge reading which probably serves to stabilise it off road. The problem is that when you change tanks, if the fuel levels are very different, the gauge takes 30 mins to adjust unless you turn the ignition off and back on again.

As a result I’ve been pondering on a way to resolve this and also to give a more believable fuel gauge reading for the current selected tank. The battery/fuel monitor will now drive the dashboard fuel gauge directly, bypassing the normal speedo circuit. The monitor will be connected directly to the two fuel tank senders and I can then calibrate the sender for each tank in the firmware. It will also light up the dashboard “low fuel” warning light (another job the speedo does at the moment). I got the gauge driver hardware/software working today, I just need to change the display to a smaller 2 rows x 8 characters display to make it easier to mount it somewhere in the dash.

Fuel and Battery Status Display

Battery monitorThe dual battery system has been missing a couple of things since I first installed it and I’ve spent a few evenings this week playing with a PIC chip and an LCD display. The aim is to have some way of checking the charge level of both batteries and to control the automatic charging of the secondary battery when the main battery is at a reasonable voltage. It will always have the manual overrides of either permanently connecting the aux battery (to jump start the main) or having it disconnected if I want to put all the charge into the main.

As the PIC chip I’ve chosen has plenty of spare capacity I also added provision for it to display the fuel level in each fuel tank too, alternating every 10 seconds between the fuel levels and the battery levels/voltage.

I’m currently using a 16×2 character display but the finished version will be 2×8 characters, allowing it to take up less dashboard space. The programming is just about done apart from calibrating the fuel levels against the two sender units, just need to build the design into something a bit smaller now !

The chip I’m using has another 4 spare analogue inputs so I might add some additional warning monitoring into it yet. Maybe gearbox temperature, fuel pressure perhaps, turbo boost pressure, I’m fitting a dedicated monitoring system so I’ll see what that’s missing and maybe add them into this chip/display. It’s always better to know when something’s starting to go wrong rather than a complete failure being the first sign of trouble.

Ready for the snow… I think…

ARB compressor and airline connectorThe last few days have been busy finishing off a number of jobs in final preparation for the trip to Scotland for the Muddy Truckers Trophy, the weather forecast hasn’t improved any… if anything it’s got worse, it’ll be a cold one that’s for certain.

Anyway, got the internal rear window guards all fitted in the back and the rear work lights wired up. The auxilliary fuse box is completely wired back in and providing power for everything it needs to, including the fridge although that may not actually be a necessity for this trip given the forecast temperatures !

Auxilliary fuse boxThe ARBs came back from Crown Diffs so I fitted the rear one together with the spare Ashcroft half shafts. I’ve had those shafts since 2008 when they formed part of the spares kit we took to Australia. They were never used so it makes sense to upgrade the 90 axles with Ashcroft shafts and CVs. The front axle will have to wait until after the Muddy Truckers though as we’re missing a couple of bits.

I plumbed in the ARB compressor, running the pipework for both front and rear diffs, the winch free spool and an airline connector on each side of the vehicle for blowing up tyres etc…

Window guards

Other than packing some tools and the rest of our camping gear, clotting, food, water etc… we’re about ready to go. The pile of bits in the dining room is definitely diminishing 🙂

Back on the roof !

Roof tent mountingWe re-fitted the roof tent today after it’s winter break. It’s actually barely above freezing during the day at the moment but we’ll be camping in it at the Muddy Truckers Trophy so the sooner it’s back on, the better. There’s snow forecast in the run up to the event, fingers crossed that changes !

As with getting the tent off the roof in the first place I decided to use the strap and winch ramp technique. With a long strap from the roll cage to the end of the bumper on my challenge motor and a second strap from the cage to the winch (allowing that strap length to be “adjusted”) we placed the roof tent on the trusty Black and Decker work bench then drove the challenge motor backwards. As the straps tightened the roof tent was lifted off the work bench and then it’s just a case of pushing the tent up the ramp… carefully !

Roof tent mounting 2For once refitting was the reverse of removal and all went smoothly. We mounted the tent a lot further forward this time to see how it would work, time will tell.

With the roof tent on I fitted and wired up a couple of LED rear work lights as we’re almost certain to be needing them in Scotland and no doubt will end up setting up in the dark on at least one night.

Roll cage finished at last :)

Spent a bit of time tinkering with the electrics, tidying up a few bits and pieces and starting to map out the circuit diagram for the aux fuse box. The aux fuse box has sort of evolved over time as each new circuit was added and I ended up with no real idea which fuse was now used for what. I now have a full circuit diagram that will sit in the top of the fuse box for reference and also allow me to wire it back up again correctly !

The side windows on the 90 have rattled pretty much since we got it and have never actually sealed properly from what I can remember. We also want to fit internal window guards at some point and all the available ones we like are designed to fit standard Land Rover pattern windows, which the ones fitted aren’t. The upshot of this is that we’ve bought a pair of new windows from Masai which are pretty much OEM spec and “guaranteed” not to rattle so we can get rid of the bits of card/cloth/paper that have been pushed into the joints in an attempt to stop it rattling.

The first problem with changing the windows is the fact that the roll cage is in the way so replacing the windows first involves removing the whole of the rear half of the roll cage. When we fitted the cage we left four bolts out (two on each side) because to drill the holes meant marking them then taking the rear of the cage off again. So, as well as replacing the windows now was the time to finally finish off the cage installation !

It took pretty much the whole day to do the job as, as it turns out, not only did the old windows not use OEM catches they were also a different shape ! This meant quite a lot of time was spent cutting and filing the existing opening out to make it big enough for the new windows. Eventually though the windows were in and the roll cage refitted complete with the new bolts to connect the top of the sides with the internal hoop. While the rear cage was off I also made some gaskets to go between the cage mounting plates and the body, cut from a large sheet of butyl rubber that used to line our pond.

First tests show that the windows don’t rattle and they seem to be water tight… so that’s a bonus !