Writer Resto: 1964 Dodge AT4 353 Part 4

As you may recall from our introduction to the Writer Resto all those weeks ago, the wiring of the Dodge AT4 was less than optimal. Over 55 years its prior owners had spliced and cut the original loom to suit their varied needs, the toll of time and the relentless Aussie weather conspiring to degrade what remained of the once-flexible insulated cable, and the precious copper inside.

In a manner of speaking, the wiring was knackered; completely beyond salvation. There was little point in ‘cutting and shutting’ what remained, the only option now a complete and professional remanufacture of the loom to what I’d called ‘improved factory specification’.

You see, like most auto manufacturers, then and now, Dodge built the AT4 to a price. Although it was one of the only trucks on the market in 1964 with an alternator, it was also one of the few that omitted a fuse box. The AT4 used a resistor arrangement to regulate current to the cabin with no real way of arresting any surge that might damage the appliance in use. Or the whole lot!

Given the AT4’s appliance list extended to gauges, lights and a wiper motor that’s hardly a big deal. But in the interests of doing things correctly – and because I’m adding a couple of mod cons to the cab – the chance to start from the start was one I couldn’t pass up.

As luck would have it, a copy of the Dodge’s original wiring diagram was available on the ‘net. I traced the wiring and matched the myriad coloured leads to their original destination, then worked backwards to see where the whole mess originated.

It turns out the AT4 run everything – and I mean EVERYTHING – from the keyed ignition, a total of eight wires feeding the remainder of the appliances in the truck.

Interestingly, one of those wires then supported a further 12 wires from the headlight switch, a couple were for the indicators, while one each run to the wiper motor and horn. The remainder handled the coil and starter, brake lights and instruments.

Many of the connections between the cabin, the engine and the rear of the cab were via exposed (!) terminal blocks, a perished rubber grommet stopping chaffing of the loom through the firewall. The lights didn’t light, the wipers didn’t wipe and the horn didn’t horn. In short, nothing worked.

The thought of attempting to restore what remained of the AT4’s electrics sent my mind racing for the fire extinguisher, so I set to work on starting from scratch. Having a mate who’s an avionics technician means the right advice is never far away, and through thoughtful consideration of the desired result, it was decided a simple ‘relay logic’ arrangement (backed by a fuse panel, see pics) was the way to go.

Once extracted from its original route – and carefully photographed – the original loom provided the blueprint for the new cabling. The original path of the wiring would be followed to ensure the right look under the bonnet, but the connectors and binding would be uprated to bring the AT4 into the 21st century.

Checking that the coloured cable purchased was capable of carrying the required current, the careful laying of colour-coded and labelled wire commenced decorating the peg board. Piece by piece the spaghetti of brightly coloured cable began to resemble an automotive loom; the ‘measure twice, cut once’ mantra employed repeatedly before wasting expensive wire.

Once satisfied with the structure of the loom – and before getting excited with the loom tape – the newly made ‘buzz rope’ was laid in place, ensuring the length of its various ends was sufficient to reach the appliance it would supply. Only then were decisions made as to where water-proof connectors would be placed and terminal plugs fitted. Then, and only then, would come the sticky loom tape.

Sadly, the AT4’s original push/pull switchgear had to go (it was well beyond its used-by date), replaced with an array of push on/off buttons etched with standardised icons. A new keyed ignition replaced the clagged-up original, and provision now exists for a (hidden) radio and bum-warming heating elements.

In keeping the system safe, the entire web is protected by a fuse block with relays installed for higher amp appliances like the horn, headlights and seat heaters. Candescent globes will remain throughout to give the AT4 a period-correct look, any added modern ‘luxuries’ carefully secreted from view.

Obviously there’s progress being made in parts of the AT4’s restoration I’m yet to write about. Over the coming weeks I’ll share updates on the body work, remanufactured upholstery, driveline rebuild and a few other gritty details.

Yes, the sequence might seem a little out of whack to professional rebuilders, but I’m one guy doing most of the work after hours in his garage. Anyone’s that’s ‘been there’ will know the struggle.

As I said in previous updates, I don’t have a timeframe for the AT4 to be completed as much of the build will depend on the state of my bank balance. I will, however, endeavour to update the Writer Resto on trucksales.com.au as progress is made and look forward to sharing the remainder of the journey with you.

Related reading:
>> Writer Resto: 1964 Dodge AT4 353 Part 1
>> Writer Resto: 1964 Dodge AT4 353 Part 2
>> Writer Resto: 1964 Dodge AT4 353 Part 3