It’s been a while since the last update however I have managed to make some progress over the last few weeks. I have started to make headway into the electrical side of things. First up was making a small wooden plinth that is mounted on the underside of the front bulkhead as a location for the fuse boxes and relays. I had considered a module style unit with all the fuses and relays pre wired, but what’s the fun in that?… also this way it’s cheaper and more learning involved so that’s the way it’s going.
I have been doing lots of research and learning into various ways of making a custom loom for the car and providing I stick to my belt and braces mentality them it will be more than acceptable for what is needed. So long as each circuit is overrated slightly with the cable and fused correctly then it will be safe and practical.
The mounting plinth secures nicely with some hidden fixings and whilst access is tight (it’s a very small car) it pays to plan ahead and “try” to keep everything neat and tidy…. This is quickly becoming a bit of a maze under here as I start adding the circuit's, however I intend to just get everything in and working first, then go round making everything tidy.
I have fitted two fuse boxes and a ground bus bar. The two fuse boxes are to have one permanent live for the likes of hazard lights, cooling fan, parking lights and headlight flash. This will then all work and function irrespective of the ignition position for safety. The second box will then power everything else through an ignition feed so nothing will operate without the key in position. I also intend to run my higher draw circuits through relays as so not to risk burning out the contacts on the toggle switches, however I have gone overkill on the toggles and used 25amp switches which in theory would be able to handle even the headlight amps on their own, still relay is safer as it can control the circuit through a negative throw keeping live feeds confined to one area and not lots of high draw switch live wires all behind the dash.
I have started off with basic circuits first such as the horn. This is a simple circuit that is powered through a relay as it can draw a few amps with it being a high resistance device then I moved onto more basic sidelight circuits incorporating the gauge illumination also. Each circuit is very basic really and is just a logical (to me) process of wiring and terminating correctly. I have wired up the started button (ignition fuse box only) so I can even spin the engine now off the button which is good fun, and will be even more fun when the engine runs. I then moved onto the main headlights incorporating the high and low beam. This utilises the original Spitfire column switch which will also be used for the indicators.
My circuit is very basic and uses a relay again to control the power and after much head scratching with wiring diagrams and online help I have managed to rig up the headlights that now function. So I have one toggle switch for sidelights a second toggle for headlights that are then stalk control for high or low beam. The high beam also includes a dash warning light to light up blue when full beam is in use. The only issue I had was trying to get the stalk control to utilise the flash function. I easily wired in the low or high beam circuits but had to add a second permanent live feed to the column so the flash feature worked also, this involved copious amounts of swearing because I had to strip, clean and repair my column switches due to broken contacts and a bent internal pin that was shorting my circuit… still all sorted now so I can move onto another circuit such as the cooling fan and the fuel pump.
I’ll continue to plod on with the wiring and probably just do a video walk round update when it’s all sorted. I have spent some more time in the garage today and I’m considering revising my rear fog light combined with the number plate light. Whilst the concept I had works fantastic and looks great but after consideration today it’s extremely vulnerable to moisture ingress that will quickly short out. So I’m going to have a think and see if I can make it more suitable…. Belt and braces after all.
I have already made a clear plastic shield that fits internally and protects the lower cutout but the problem arises with the seal between to two chrome back plate units. They are not sealed around their perimeter and so with the lower cutout sealed with clear plastic the unit could easily fill with water during wet weather driving and then short out…. More thinking needed.
