Posts Tagged ‘dynamo’

Which Dynalite suits my car?

Posted: February 26, 2018 by goodshoutmedia in How To Guides
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A dynalite is a replacement for your dynamo, that looks like a dynamo but functions like an alternator.

You can browse the full range of Dynalites here

Here’s a handy guide to identifying which dynamator model your car requires:

Make Model Notes
Austin A40 1952-1954 C39/40
Austin 1100/ 1300/ 1300 GT C39/40
Austin A35 1959 C39/40
Austin A40 Saloon MKI 1960 C39/40
Austin A55 1960 C39/40
Austin Seven 850 1959 C39/40
Austin Healey Sprite MKI & MKII (Early) C39/40 Available with Tacho
Austin Healey Sprite MKII & MKIII C39/40
Austin Healey 3000 1964 – 1968 C42
Austin Healey 3000 1959 – 1960 C45
Austin Healey 3000 1964 – 1968 C45
Austin Healey 100 1954 -1959 C45
AC Ace (Ford Engine) C40L
Siddeley Sapphire 234/236 1956 – 1958 C39/40
Aston Martin DB2 – DB4 MKII C45
Bristol 400 / 401 / 403 / 404 / 405 / 406 C39/40
Daimler one-o-four 3.5 1957 – 1959 C45
Daimler one-o-four 4.5 1957 – 1960 C45
Daimler Majestic 1959 – 1960 C45
Daimler Conquest 1954 – 1958 C39/40
Daimler Ambulance 1949 – 1954 C45
Daimler Consort 1950-1953 C45
Daimler 2.5 1946 -1952 C45
Daimler Dart V8 SP250 C40
Daimler Regancey 1953 -1955 C45
Ford Anglia  C39/40
Suitable for all Pre-cross flow & cross flow models.
Not suitable for PINTO or V4 Engines
Ford Capri 1300/ 1600 /2000 C39/40
Ford Cortina / X-Flow C39/40
Ford Escort MKI & MKII C39/40
Ford Escort RS 1600/ 1600 TC C39/40
Ford Consul Classic C39/40
Ford Cortina/ Lotus Twin Cam 1558cc C39/40
Ford Zephyr Zodiac ( 4+ 6 Cylinder) C39/40
Hillman Husky 1955-1960 C39/40
Hillman Minx 1947-1948 C45
Hillman Minx 1953-1960 C39/40
Hillman Imp C39/40
Jaguar 2.4L / 240 1963 – 1969 C40L
Jaguar 3.4/ 3.8L/ 340 & S Models 1963 – 1968 C42
Jaguar E Type 3.8L C42
Jaguar E Type 3.8L S1 1964 C45
Jaguar XK120/ XK140/ XK150 C45
Jenson Interceptor 1951 – 1954 C45
Jowett Javelin 1952 – 1954 C39
Jowett Javelin 1948 C45
Land Rover 80 inch 1948 – 1952 C39/40
Land Rover Series I 1952 – 1959 C39/40
Land Rover Series I 1958 – 1959 C45
Land Rover Series II 1959 – 1960
Land Rover Series II 1959 – 1960 C45
Land Rover 4 + 6 Cylinder C39/40
Land Rover 6 Cylinder C45
Lotus 7 Twin Cam C39/40
Lotus Elan/ Lotus Elan Plus 2/ Sprin C39/40
Lotus Elan S4/ Sprint C39/40
Marcos 1600 GT / X- Flow 1969 – 1970 C39/40
MG 1 1/4 litre 1947-1949 C45
MG 1 1/4 litre 1950-1953 C39/40 Available with Tacho
MG TC – 1945 -1949 C45
MG TC – 1950 C39/40 Available with Tacho
MG TD – 1950 -1953 C39/40 Available with Tacho
MG TF – 1954 -1955
MG Magnette 1953 -1960 C39/40 Available with Tacho
MGA 1500/ 1600, MKII 1955 – 1962 C39/40 Available with Tacho
MGA Twin Cam C39/40 Available with Tacho
MG 1300 C39/40 Available with Tacho
MG Midget MKI (Early) C39/40 Available with Tacho
MG Midget MKI MKII , MIII C39/40 Available with Tacho
MGB 1962 -1968 C39/40 Available with Tacho
Classic Mini all years C40
Morris Minor all years C39/40
Morris Oxford 1948- 1960 C39/40
Morris Oxford C45
Morgan Plus 4 1946-1949 C45
Morgan Plus 4 1953 C39/40
Morgan 4/4 1600 C39/40
Reliant Regal 1953 – 1960
Reliant Regent 1951 – 1960 C39/40
Relaint Robin
Reliant TW9, B, C, E 1970 – 1972 C39/40
Reliant Sabre 6 C40L
Riley 1 ½ L 1946 – 1949 C45
Riley 1 ½ L 1951 – 1960 C39/40
Riley 4/68 1959 – 1960 C39/40
Riley 2 ½ L 1947 – 1953 C45
Riley Pathfinder 1954 – 1957 C45
Riley 2.6 1958 – 1959 C45
Rover 2000/ SC/ TC C42
Rover 3L C42
Sunbeam Alpine C39/40
Sunbeam Rapier C39/40
Triumph GT6 C39/40
Triumph Herald C39/40
Triumph Spitfire 1.2L/ 1.3L C39/40
Triumph Vitesse C39/40
Triumph 2000 C40L
TVR Grantura C40L
Wolseley 1100/ 1300 C39/40
Wolseley 16/ 60 C39/40
Wolseley Hornet C39/40
Vauxhall Cresta E-Type 1954 -1957 C39/40
Vauxhall Victor 1958 – 1959 C39/40
Vauxhall 10HP – 12HP 1946 – 1947 C45
Vauxhall Friary 1955 – 1957 C39/40
Vauxhall Dormobile 1955 – 1957 C39/40
Vauxhall Grosvenor 1955 – 1957 C39/40

It is important to have your voltage regulator working correctly, especially with electronic ignition because over voltage can shorten the life of many components on a classic car.

Our electronic distributors and electronic conversion kits operate between 6 & 16V. A faulty dynamo or voltage regulator/alternator can overcharge putting out voltages between 25 & 30V which is far too much for modern electronic ignition systems and other sensitive electronic components to cope with.

Alternators have their voltage regulators inbuilt as a complete unit and a simple voltage test at the battery terminals with the engine running should show between 13.7 and 14.5 v After testing if you do have a faulty dynamo or voltage regulator ask about the new Dynamator range which have original dynamo looks with the practicality and reliability of modern alternator electronics.

We can supply both negative and positive earth versions also available with the tachometer drive.


Two tests here.

  1. Test the point contacts first. Disconnect the battery GROUND cable. Using an multi meter, test reading between terminals A & D (terminals electrically on opposite sides of the points) and you should have nothing as cutout points should be open. Now manually close the points by pushing on them (OK to do with battery disconnected). Good points should read near zero ohms. If not, try making connections closer to the actual points to narrow down where the resistance is. If you do not have a ohm meter connect a test lamp between D and the battery terminal you took the ground strap off. Lamp should not light with points open and should be bright when points are closed. Any excess ohms or dimness in bulb will indicate point corrosion or other problems.
  2. Next you need to test the coils. Reconnect battery and start the engine and idle. With volt meter between terminals D & E you should be getting 6-12 volts (lower at a low idle and higher at a high idle). Rev engine up to1500 RPM and you should get 13.2-15 plus volts (depending on state of battery charge (lower if battery is fully charged and higher if battery is low). Do the same test at terminals A & E. A is tied directly to the battery so you should never go below battery voltage. Once dynamo matches battery and points close then reading at A will go up from battery voltage and increase with dynamo output. If this is not the case then there may be a dynamo problem or a regulator problem.


Again there are two tests. To test the actual points you need to disconnect the wire leading to the F terminal. Then put an ohm meter between the terminals F & E. You should get near zero ohms with good points. If it is higher try connections as close to the points a possible to narrow down where the resistance is. Now open the points. It should increase to around 60 ohms as a resistor takes over the circuit.

To test the coils connect a volt meter between F & E and set the engine at idle. At idle you should be seeing the same voltage as at the D & E terminals (probably 6-12 volts). Increase the speed of the engine and voltage between F & E will rise as the dynamo feeds the battery. Increasing the RPMs further, you will see the voltage peek and then start to decline. At about 2500 RPM you may only be seeing 8 or less volts. What should be occurring is the regulator is regulating the dynamo field windings to prevent it from destroying itself. Dynamo output is related to how much voltage is being fed to the dynamo field windings and how fast it is spinning.

Put the same voltage to a slow spinning dynamo and a fast spinning one and you will get much greater output at the faster RPMs. So to keep control, and prevent dynamo burnout, the regulator senses output and drops voltage to save the dynamo at speed.

If voltage does not follow the above pattern then the regulator needs adjustment or you have a defective dynamo.


The alternator or dynamo is at the heart of a vehicle’s charging system, providing power to the various electrical components while the engine is running and also making sure the battery is always charged.

The quickest and easiest way to check if your alternator is under/overcharging is to measure the voltage across the battery terminals. DO NOT DISCONNECT ANY OF THE BATTERY LEADS WITH THE ENGINE RUNNING AS DAMAGE TO ELECTRICAL COMPONENTS MAY RESULT! Using a digital multimeter and with the vehicle engine running at tickover with no electrical accessories switched on, check the voltage output across the battery terminals.

Anything between 13.5 volts to 14.5 volts tells you the alternator/dynamo is charging around the correct parameters. Anything lower than 13.5 volts shows it is not putting out enough power to charge the battery efficiently and electronic items on the vehicle may behave erratically.

If there are more than 14.5 volts produced from the alternator/dynamo or voltage regulator (separate on positive earth vehicles) then it is overcharging, sometimes producing higher voltage “spikes” which can produce too much voltage for sensitive electronic components, causing them to fail or create intermittent electrical faults.  Also check on the condition and tension of the alternator/dynamo drive belt as if it is too loose or in poor condition the belt may slip causing the alternator to have a low output.  Alternatively if the belt is too tight it will damage the alternator/dynamo bearings.

This is a basic charging test for alternator/dynamo output.