LED Map Light

 LED Dash Illumination  No Responses »
Feb 012013
 

The map light on the underside of the dash isn’t that bright and so is being replaced by a string of three pure white LED strips; two outer 15cm lengths and a central 10cm length.

I added the middle length in an attempt to make sure the central area, where the standard bulb fitting is located, had equal illumination. The strips are backed with a 3M adhesive tape so it is simply a matter of removing the backing, pressing into place and connecting to the wiring loom via bullet connections.

Heatshrink tubing was used to tidy up the connections between the three strips and hide my dodgy soldering. All that remained was to temporarily fit the dash top to test.

Testing of the Map Light

The minimum order for the pure white LED strip was 2 metres so I had more than 1.5m left over. It seemed a waste not to use it so I looked to see if it could be used ‘tastefully’ elsewhere but was mindful of avoiding making the car look like a victim of a fight with the Halfords aftermarket department!!

A discreet light in the boot, operated when the bootlid is opened, will be covered at a later stage ….

First stab at routing the wiring looms

 Electrics, Rebuild, Routing Looms  No Responses »
Jan 152013
 

Unfortunately the number and quality of the photos taken of the routing of the wiring looms during the dismantling was woefully inadequate! The three photos below were the only ones of any use but at least they gave a starting point for the main and dash looms.

The main, dash and alternator looms route behind the glovebox. The dash loom joing the LHS body harness in this corner The fuse boxes and wiring looms behind the centre console The dash loom behind the steering column mount

Dash Loom
The dash harness was first to be fitted and it’s fairly obvious how it is routed as it is just held in place by the protruding tabs along the dash length. The tabs were covered with heatshrink to avoid chafing. Its lateral positioning was determine by referring back to the dismantling photos and the group of mainly green and purple wires needs to be directly below the right hand fuse boxes.

Main Engine Loom
The engine and front lighting loom was next to be added. The length running in the cabin also runs behind the same protruding tabs. The loom then passes through into the engine compartment via a hole in the left hand footwell and along the upper tube of the left sub-frame. The alternator spur is fixed to the sub-frame with a P-clip. The remainder of the loom passes down, across and then up the picture frame and finally back along the upper tube of the right sub-frame. Two more P clips, on the bottom bolt of each of the upper front wishbone brackets, are used to secure the loom to the picture frame.

Alternator Loom
The alternator loom follows a similar route as the main engine loom using the same hole in the footwell. Obviously only going as far as the alternator.

Fan Looms
The fitting of the fan looms will have to wait until the fan relays and fans have been installed.

Re-wiring starts with the dash loom

Left & Right Hand Body Looms
The routes of the two body looms are a mirror image. They start just below the windscreen pillar where they are connected to the dash looms. From here they drop down and travel forward running behind a protruding tab which can be bent back to secure it in place. They then run within a indented channel on the inner sill until they reach the rear bulkhead.

They pass up the bulkhead/wheel arch join, entering the boot space via holes in the vertical section of the rear bulkhead. Inside the boot space, they run directly upwards and then rearwards behind more tabs before passing into the wheel arches via holes just behind the bootlid hinges.

EDIS Megajolt Looms
As I had opted to install EDIS Megajolt electronic ignition system this will need to be installed before the other dash components are put in but I’ll cover this installation in another entry.

A problem solved ….
One issue has now been resolved. During the labelling of the looms I found that they were missing the green & brown wire for the reverse light switch. There’s a sundries wiring pack that is needed in addition to the six main looms and it contains the separate wires such as the reverse wire, dash illumination and a few switches/gauges wires.

Let there be light … LED dash lighting

 Electrics, LED Dash Illumination  No Responses »
Jan 012013
 

The backlighting of the dash gauges is provided by incandescent bulbs inserted into the rear of the gauges and is fairly poor by modern standards. The green hue of the backlighting is achieved by coloured plastic covers within the gauges and green plastic tape behind the switch legend strip. However the heat produced by the bulbs had melted several of the covers.

The backlighting can also be set to Bright, Dim or Off via the 3-way Panel Switch. The light produced by these bulbs is almost linear to the applied voltage. When bright is selected, 12 volts is applied across the bulb terminals. While switching to Dim introduces a resistor in series with the bulb. This produces a voltage drop across the resistor and therefore the voltage applied to the bulb and the emitted light is reduced.

One popular ‘upgrade’ is to replace the bulbs by LED strips mounted around the perimeter of the inside of the gauges. LED strips are available either containing a single LED colour group (eg white, red, green, blue, yellow) or all three of the additive primary colours; red, green and blue.

The latter, for obvious reasons referred to as RGB LED strips, can output different light colours by adjusting the relative intensity of each LED colour group. The LED strips also have the advantage that they are more efficient and do not generate a large amount of heat.

The upgrade is well documented in Stéphane’s guide on the E-Type forum. One of the members had tried the upgrade with blue LEDs and I thought this would suit my car, being Opalescent Dark Blue, but I was undecided whether I wanted to lose the original green.

I couldn’t decide which I preferred so I investigated the possibility of being able to switch between the two. In the end I decided to use the RGB LED strips and somehow try to use the spare dash switch (used for the heated rear window on the FHC) to toggle between green and blue. This would lead to numerous problems that would only become apparent as work progressed.

The LED strips currently on offer vary in the number of LEDs per metre; typically 15, 30 or 60 LEDs per metre but also in the strip width; either 8mm (3528 chipset) or 10mm (5050 chipset) and with or without waterproof covering. The aim was to increase the brightness of the backlighting but with the constraint of space within the gauges. So I thought the thinner strips with the waterproof option would be sensible, so I ordered the following:

  • 2 metres (min order) of 3528 Pure White 60 LEDs/m – for the dash map light
  • 5 metres of 3528 RGB 60 LEDs/m – for the gauges

The strips with 60 LEDs per metre can be cut every three LEDs, ie every 5cm. This was ideal as the inner circumference of the smaller gauges would allow a 10cm strip. However the first problem came to light, excuse the pun, when I tested the 3528 RGB strip. This chipset used has one LED for each of the three primary colours in a 5cm strip. When either blue or green is selected, only one of the three LEDs was illuminated. So in the 10cm strip possible, lighting would only be provided by two LEDs – hardly an improvement!

After a few calls to suppliers, it became clear that I needed the wider 10mm strips for the multi-colour option. Each LED in the 5050 chipset is effectively made up of three LEDS; one for each of the red, green and blue colours. So all six LEDs in the 10cm strip would provide light. If the additional width caused a problem I would give up on being able to switch colours and revert back to a single coloured 8mm strip.

While I was planning how to incorporate the upgrade into the existing switch layout I noticed something really odd in the wiring diagrams which I couldn’t understand. The power for the dash illumination is only provided when either the side or main headlights are on. This made perfect sense – if it’s dark enough to need lights then you’d always want to illuminate the gauges. So why did the Panel switch have three settings: Bright, Dim and Off? Why on earth would you ever want to have the side/head lights on and not the dash?

I started to doubt the wiring diagram and so posted the question on the forum. Apparently in the 60s it was a legal requirement when parking at night to have the side lights on. In which case the dash illumination was turned off to conserve the battery. I don’t think I’ll ever need his feature so I’m considering swapping to a two state Panel switch – Bright and Dim.

With the planning done, the next step was to start to dismantle the gauges ….

Black Art of Car Electrics

 Electrics  No Responses »
Feb 212012
 

The intention had always been to replace the existing wiring loom, which had had its fair share of modifications in the past. Much of the braided covering had either been caked in oil over the years or had disintegrated. As it was to be replaced and to speed up its removal, I had cut the loom where it passes through the bulkhead and removed it in two sections.

Fortunately, at the time of removal, I wasn’t aware that the loom was in fact made up of a number of looms. So the two sections were boxed and not separated into the individual looms. I was thankful of that when I came to deciphering the wiring diagram against the new looms, as I was able to refer back to a complete loom.

I was fairly confident that I wouldn’t have too many problems doing the re-wiring (pride before a fall?). Just in case, I purchased a copy of a wiring diagram produced by Coventry Auto Components which was to supplement the Jaguar service manual diagram. You can never have too much information ….. unless it’s conflicting or incorrect!

Somehow the old loom had turned itself into a right old bird’s nest while in storage. It took quite a while to untangle it so that it could be laid out, mimicking how it is routed within the car. Armed with a multi-meter and the wiring diagrams, I set about the simple task of labelling the new looms …

… four days later the finishing line was in sight. I had printed a large copy of the wiring diagram which was used to track the progress. Wires that had been identified were labelled at both ends indicating what they should be connect to and then highlighted on the diagram as ‘accounted for’.

The wiring convention used by Jaguar employs colour codes to signify the type or purpose of the wire, eg green for a regulated, fused source. Therefore a loom would often have a number of wires of the same colour. Once a wire disappeared beneath the loom’s braided sleeving, it wasn’t always obvious which of the similarly colour wires reappearing was it’s other end! So a multi-meter, set in continuity mode, was extremely handy and took out the guess work.

Other issues that, for now, remain unresolved are i) a missing green & brown wire for the reverse light switch and ii) a spare purple & white wire at the centre of the dash. The E-Type forum is very helpful in cases like this as there’s a wealth of knowledge available from the forum members. I was not alone with both the missing and extra wires as one member had decided to use the spare purple & white wire for the reverse light switch. Perhaps I’ll need to do the same.

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