Several years ago, when contemplating the electrical system upgrade, of my British specification, 1973 VW "1600" Type 2, Westfalia Continental campervan, without resorting to expensive accessory fuse boxes and relay boxes, such as those available from Vehicle Wiring Services, I explored the possibility of adapting second-hand parts, salvaged from a variety of car marques.
http://www.vehicle-wiring-products.co.uk
Phase 1, was to substitute a modified fuse & relay box, salvaged from a Vauxhall Cavalier Mk.2, which has basic provision for eighteen plastic blade fuses (available in 3, 4, 5, 7½, 10, 15, 20, 25 & 30 amp ratings) and four standard relays, each having up to five 6•3 mm (i.e. ¼-inch) male blade terminals. I also salvaged additional 1, 2 & 3-position (i.e. sharing a common supply cable), blade-fuse, electrical connectors cum recepticles, from various other Mazda (surprisingly, they were identical!) and Vauxhall cars' fuse boxes; uncrimping the cables, so that they could be re-used in customising my own fuse box. There are five supplementary slots, for clip-in plastic modules of two types, which accommodate either a single relay or two plastic blade fuses. Vauxhall & Opel, are the British & European division (or divisions), of the General Motors Corporation.
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To accommodate the VW headlamp dimming relay (North American specification - VW part No. 411 941 583 C) or headlamp dipping & flasher relay (British & European specification - VW part No. 411 941 583 B), I modified one of the black plastic, supplementary double fuse-holder modules, by heat welding in the appropriate section from the original VW Type 2 fuse cum relay box, using a flame-heated pallette knife and an electric soldering iron.
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The plastic, supplementary relay-connector cum mounting blocks I used, were coloured black, but others, coloured purple, light-blue, green and yellow, are also readily available. They are of the same terminal-recepticle configuration, as relay positions 3, 4 & 5, of the stock 1971~79 VW Type 2 fuse & relay box; having recepticles numbered 2, 4, 5, 6 & 8, for five latched, 6•3 mm female blade-connectors, plus recepticles numbered 1, 3, 7 & 9, for four latched, 2•8 mm female blade-connectors.
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The coloured plastic, supplementary relay-connector cum mounting blocks, fitted to various Vauxhall car model's fuse & relay boxes, can also be used as trailing connector blocks for accessory relays, remote-mounted using their own integral mounting brackets. The different colours, also serve as a reminder about which connector blocks, are associated with which relays. I previously used one of these coloured connector blocks, for a relay mounted in the engine compartment, which served the electric de-icer element, for the single Minnow Fish carburettor, on my 1973 VW 1600 Type 2, AD-series, twin-port engine.
In addition to these, there are alternative relay-connector cum mounting blocks, of Rists (a division of Lucas Industries) and/or RWC brands, available in a variety of colours, including black, white & red, fitted to the British, Austin Montego, Maestro & Metro car models, which can either be mounted on brackets or used as trailing connector blocks. They are of the same terminal-recepticle configuration, as relay position 1, of the stock 1970~79 VW Type 2 fuse & relay box; having recepticles numbered 30, 85, 86, 87 & 87a, for five latched, 6•3 mm female blade-connectors, corresponding to the typical terminal labels, on 5-terminal relays.
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Phase 2, involved retro-fitting a pair of unmodified, six-position, relay mounting cum connector blocks, salvaged from Austin Montego and/or late-model Austin Metro cars. These are fitted beneath the horizontal steering-column support bracket, using custom, home-made duralumin brackets, which also conceal the electrical cables from view. When the brackets are painted satin black to match the dashboard and steering column, the installation will have a virtually factory-fitted appearance. If in the future, I need to make provision for more relays in the cab, I might fabricate some longer, replacement duralumin brackets, to accommodate a total of three, six-postion, relay mounting cum connector blocks.
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Knowing that I would wish to site accessory relays and fuses in the engine compartment, I modified an enclosed fuse & relay box, salvaged from a mid-1980s vintage Lancia Delta, which has provision for sixteen ceramic fuses (available in 5, 8, 16 & 25 amp ratings) and seven standard relays, each having upto five 6•3 mm (i.e. ¼-inch) male blade terminals. I envisage using all of the relay positions, but will probably have a few unassigned fuse positions!