are powerful enough to cope with the demand for
a modern car's electrics, but dynamos often are not. So if your car has a
dynamo, and its output is inadequate, it makes sense to swap a dynamo for an
Removing the old dynamo and fitting the alternator are fairly
straightforward. The main difficulty is mounting the alternator, because it is
a different size from a dynamo, and wiring it in.
, remove the
drive belt and take out the
dynamo. Wrap, in plenty of insulating tape, the thick
wire that ran to the dynamo D
so that it cannot touch the
The rear of the dynamo is mounted to the
via a right-angled
bracket, one end of which bolts to the block, the other end to a mounting point
on the rear casing of the dynamo.
Look to see if there is a second mounting point on the block just forward of
the existing one. If there is, you can simply unbolt the mounting bracket from
the block, move it forward and bolt it into the new mounting point. You can
then mount the alternator in place.
If there is no second mounting point, you have two choices. The easier
option is to buy a special, extra-long mounting bracket, bolt this to the
block in place of the old bracket, then mount the alternator to that.
But these brackets are not available for all cars, in which case the
alternative is to adapt the existing mounting point to take the alternator.
If there is a second mounting point on the engine block, or if you can buy
a conversion bracket, offer up the alternator to its mounting
It should fit snugly, but you may find that the rear mounting point on the
alternator does not butt up to the bracket on the block. If so, you need to
adjust the alternator's rear mounting. Find the short metal tube on the
mounting and use a small hammer to gently
this tube forwards or backwards
until it just touches the mounting bracket. Now bolt the alternator in
Use a ruler to check that the pulley is in line with the
pulleys. If it isn't, you will have to place washers between the
alternator and its front bracket until it is level.
If you have to use the existing dynamo mounting point, first bolt the
alternator to its front mounting point. Check the alignment of the alternator
pulley (see above).
Now tap the tube on the rear mounting as far through the bracket as it will
go. If it doesn't reach the rear mounting on the engine, cut a length of metal
tube to run between the end of the tube and the bracket on the engine.
Fit a long bolt through the rear bracket on the engine and pass it through
the piece of tube you cut. Push it through the rear mounting point on the
alternator, then fit a washer and nut to it - leave the nut loose for now.
Fit an eye connection to one end of your cable and a multi-connector
plug to the other end. Then attach the eye end to the
or battery live terminal and the other end to the ± terminal on the
Attach the small terminal that fitted to the dynamo F terminal to the
alternator IND terminal using the multi-plug.
, disconnect the F and WL wires and join them together.
, with cable sizes, is shown.
Attach the slotted adjuster strap to the alternator and to its mounting
point on the engine. Ensure that the alternator pivots freely.
You may find that you have to bend the slotted strap to make it fit. If that
does not work you will need to buy the correct strap for the alternator. Fit a
new generator drive belt and tension it correctly.
The alternator needs to be connected to the
warning light and to
either the input terminal on the starter solenoid or the live battery terminal.
Using 97/.012 (97/.30) cable, measure how much you need and cut it to
Attach a suitable connector to each end of the cable, and connect it to one
of the large terminals in the rear of the alternator marked + (it doesn't
Run the cable to your chosen live point following the wiring loom. Use cable
ties or insulating tape to secure the cable. Connect the free end of the cable
to the starter solenoid or battery terminal.
Now find the small wire that was connected to the dynamo F terminal Connect
it to the terminal on the rear of the alternator marked IND. Next move to the
voltage regulator unit, and find the terminal marked F or DF and pull off the
wire from it.
Do the same with the wire on the WL terminal. Join the two wires together,
and insulate them. You can leave all the other wires attached to the voltage
regulator - it acts as a useful junction box.
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If your car's instrument panel includes an ammeter, it will tell you how well the charging system is working - the difference between the charge going into the battery and the power being used from it.