Electronics Overhaul

I’ve recently undertaken a project to redo a significant amount of the electronics and wiring in the taxi, partly because a lot of it wasn’t working due to water ingress (see how I solved that here) and partly because the wiring has turned into somewhat of a spaghetti mess over the years, thanks to the addition of many little bits and bobs here and there.

I want to keep this an easy read, but also be as informative as possible. So I’ll write one fairly comprehensive summary here and delve deeper into some areas as separate articles.

Before doing anything with the electronics, you’ll need to get the dashboard off. Thankfully in a fairway this is a fairly straightforward activity, as it only held on by 4 self tappers and the two bolts which hold the passenger door rope onto the firewall.

You’ll have to remove all the switches, speakers, dashboard, steering wheel (with a 32mm socket) and vents. Again, straightforward, with the possible exception of the speedo cable at the rear of the instrument cluster which can be fiddly. If you’re struggling to remove it, rest assured there is no secret you’re missing out on, it’s just a pain and requires some dexterity and strength to haul it off.

For a quick video and more information on how to get the dashboard off, check out the following article:

• Dashboard Removal

With the dashboard off you’ll be faced with a lot of wires and connectors in varying degrees of complexity depending on your individual car. When these came off the production line, they weren’t fitted with many extras, which left it down to the driver to add what he/she wanted. My fairway has had a lot of different bits and pieces wired in, including (but not limited to) remote locking, electric front and rear windows, intercom, DAB radio, immobiliser and there are still some remains of a previously removed air conditioning system.

A lot of these bits are situated in the centre console, so the wiring is somewhat of a bodge and the power distribution to these modules is a complete shambles. I understand why this happens, as when you buy an ‘add-on’ kit, such as a remote locking module, the instructions usually direct you to use the cars existing wiring and just crimp onto any wire available. Whilst this is fine for one module, it starts becoming unmanageable when you’ve got 5 or 6 sets of additional wiring tangling up with each other. Fine, it probably all works at the time, but these wiring bodges don’t tend to last long and when something does need fixing it becomes a nightmare.

When I first got my hands on the wiring, the power was being supplied from the fusebox, via the Green/Pink wire and then through a series of black connectors to distribute it to all the various bits. To make things a bit more complicated, the +12v was being split into black, brown, red and green cables…

I was confident that the green/pink wire was rated sufficiently to carry enough amps (approx. 25A) to all the electronics without melting, so the first thing I did was to extend it and put it onto a bus bar and remove all the extra wiring.

This cost around £15 on eBay, however it means I could completely tidy up all the power distribution and makes for easy additions in the future without the need for crimping another dodgy connector onto a random wire. When I installed it, I removed the tie between the two bars, so I could use one for +12v and the other for ground.

The majority of the work involved getting rid of useless traces of wire which obviously served some purpose at one point, but hadn’t been removed along with the old units they were connected to. By the time I had cleared up the wiring, the two main pieces which remained were the intercom and remote locking unit. You can see the difference before and after in the pictures below.

For more information on specific areas of the wiring shown above, please browse the following separate articles:

• Electric Windows
• Intercom

Now the central console had been tidied up, I was left with a handful of random wiring which was being sent to the passenger compartment. To investigate this further, I took up the carpet and checked out where they were all going.

One or two cables were from the previous immobiliser unit, so I removed them and I was left with these cables. Most are to do with the [intercom unit], some for the rear speakers, a couple more for the electric window and one for the reversing camera signal.

Now, to the dashboard (and going back to the initial point raised in this article), a lot of the wiring situated underneath the windscreen had suffered from water ingress. This meant some of the relays and connections had corroded which doesn’t make for a reliable system. Most importantly, the fusebox connections were next to useless and therefore provided endless issues with all the various aspects of the electronics in the taxi. Even though the leaky windscreen has been sorted (for now…) I still wanted to re-wire the fusebox with new connectors and move it elsewhere, so this wouldn’t be an issue in the future.

For more details, please see the following article:

• Fusebox replacement

Moving outside the vehicle – there has always been a reliability issue with the HID Xenon headlights which I installed years back. With conventional halogen bulbs there wouldn’t be much of a problem, as halogen bulbs will light up at any voltage, albeit dimly (which is why I naively thought to replace them!)

In layman’s terms, HID kits need 12-14v and some beefy amps to work properly, as they use a ballast box to convert this to 15,000v in order to fire up the arc on the Xenon bulbs. On my taxi, the wiring was just so old, the connections so poor and bodged up that the power getting to the ballast box was never really sufficient for them to fire up reliably. Just like the fusebox, a lot of wiring needed replacing.

I replaced the wiring at the lamp with new heat shrink crimps and H4 connectors to make sure there was no contact issues at this end of the circuit. I also made some important adjustments behind the dashboard to reduce the length and complexity of the circuitry, which you can see in more detail in the following article:

• Headlight re-wire

Whilst in this area of the car, I also replaced the indicators with brand new units, as well as the associated wiring.