Contents Introduction The aim of this book A little knowledge Back to basics Range of models covered Tools, equipment & workspace Chapter 1 – Safety Chapter 2 – Auto-electrics – an overview Why do we need an electrical system? Let’s look again at the starting sequence Chapter 3 – Back to basics 1 – basic electrical theory “Electricity is the flow of electrons” Simplified atoms ...and molecules Conductors ...and insulators Polarity and electron flow – +/- & earth (ground) Earth (ground) Chapter 4 – Back to basics 2 – basic circuit theory & useful information Amperage (I) Voltage (V) Resistance (Ω) Resistance rules Circuits The vehicle circuit diagram One circuit, many branches Chapter 5 – Magnetism & electricity The permanent magnet The electromagnet The loudspeaker voice coil The solenoid The relay Horn The electric motor The permanent magnet motor Chapter 6 – Measuring Current & Diagnosis The multi-meter The live-tester Chapter 7 – The five systems The battery 1. The charging system 2. The starter system 3. The ignition system 4. The lighting system 5. Accessories, ancillaries, or auxiliaries Chapter 8 – The battery How a battery works The lead-acid battery Cells Voltage Capacity Battery casing Battery life Battery maintenance External Internal Charging Jump-starting or booster-starting Jump-start procedure Jump-starting with two batteries Jump-starter packs Battery handling and safety Battery testing and the science bit Heavy discharge test Simple volt-meter readings Hydrometer test The science in a nutshell Discharge Charging Chapter 9 – Generator 1 – the DC dynamo Dynamo maintenance Bearings Brushes & commutator Cleaning Testing Windings Testing the dynamo output Commutator care The voltage regulator/control box Dismantling a dynamo Maintenance Cleaning Checking & adjustment Regulator check and adjust for a three bobbin regulator Regulator check and adjust for a two bobbin regulator To check and re-set the cutout Three bobbin Two bobbin Chapter 10 – Generator 2 – the ac alternator Alternator construction Alternator maintenance & servicing Replacing a dynamo with an alternator Control box and polarity change Chapter 11 – The starter motor Starting the engine The inertia starter Pinion stuck in mesh? Inspect brushes & commutator Removal Cleaning the pinion & commutator Fitting new brushes Dismantling the motor New brushes Bushes Remove pinion The starter solenoid The pre-engaged starter motor Removal from car Cleaning the pinion set Dismantling Dismantling the lever and pinion set The starter motor tests In car tests 1. Battery 2. Cables and connections 3. Volt-meter tests 4. Starter motor out tests Chapter 12 – The ignition system The coil How it works The distributor The rotor-arm The contact-breaker The HT leads The sparkplugs The ignition tests The HT leads and plugs Contact-breaker Replacing the contact-breaker Contact-breaker points gap Timing the ignition Timing marks Static timing Dynamic timing with a stroboscope Upgrading the ignition system Contact-breakerless ignitions Chapter 13 – Lighting The headlamps Four headlamps? Replacement of a sealed-beam unit Semi-sealed units Earlier headlamps Stop, tail, and sidelights Maintenance of brake and sidelamps Lights and the law Direction indicators or trafficators Additional lamps Spot or fog lamps Reversing lights Flashing indicators Chapter 14 – Accessories Essential accessories The horn The windscreen wipers Heater fan Non-essential accessories Radio Electric washer pump Heated rear window Electric windows Alarms and immobilisers Chapter 15 – Instrumentation The speedometer Mileometer/odometer Tachometer or rev counter Temperature gauge Petrol gauge Ammeter Oil pressure gauge Mechanical type Electrical type Clock Chapter 16 – Wires, fuses & switches Wiring The loom/harness Wire and cables Colour codes and fault tracing Stress fracturing and metal fatigue in wiring Connections Screwed or bolted cable ends Push-fit connectors Scotchlok Shrink wrap Insulating tape Soldering How to solder a connector to a wire Method 1 Method 2 Earthing points Fuses Working with and around the loom Replacing a front wing Typical RQP or mid-panel repair Making up a section of loom – with thanks to Mike Wood at Frost Loom swap Switches Manual switches Rotary variable switches Other switch gear Auto electrical cables and their applications (12V) Contemporary guidebooks’ recommended wiring Modern metric cable specifications British Standard (BS) wiring colour codes 1986 Further reading Introduction INTRODUCTION One of the great attractions of older vehicles is that they speak to us of a simpler age – a time when technology was within the grasp of the man in the street. So many of the gadgets we employ in today’s world are dependent on microelectronics and computerisation that we are in danger or becoming alienated from them; this is particularly evident when we consider the workings of the modern motor vehicle. Open the bonnet (hood) of your new Ford Ciabatta or Audi Doodi – what can you see? Are any of the components readily recognisable? And if they are, can you, as the owner, service or replace any of them? When my own Audi A1 took a hit, its ‘brain’ put the car into ‘emergency drive mode’, which in common parlance meant that it drove like a pig. I do, of course, accept that in doing so it may have protected some of its workings, and although resetting the ignition back to normal took my local main dealer a few minutes, it required a machine which cost more than the car is worth. A look inside modern Audi engine bays reveals ... nothing! This lovingly maintained Herald reads like a text book. Which electrical components can you name at a glance? OK, how does this compare when we examine the business end of our ’67 Anglia, E-Type, or Corvette Stingray? Usually this will present quite a different picture. In no time at all the familiar family of parts will reveal themselves – sparkplugs, distributor, coil, HT leads, starter motor etc – and all of them just waiting for us to rip them out and tinker with them on the kitchen table! And tinker we must, if we are to get the most from our beloved classics – for maintenance is the key to successfully running an older car. Back in the days when many of our cars were current or simply ‘a bit old’, reliability and service intervals were very different to those which we know regard as normal. In almost any situation it was perfectly acceptable to excuse tardiness with the words “sorry, the car wouldn’t start.” Similarly, up until the early eighties, it was not unusual for my neighbour to turn up on the doorstep of a morning asking for a bump-start; luckily we lived at the top of a hill. (Though, obviously, not so lucky if the damn thing didn’t actually fire on the way down!)