A Guide To Electrical Problems
As i have been a car electrician in a previous occupation, and it seems to be one of the things everyday people are afraid to deal with. So I thought that I could give a few general advices.
1. Grounding: It is the single most important thing to check, if you
have a malfunction in an electric device. With poor grounding you can end up
with the oddest error that will make you think that you have got ghosts in your
car. And do remember to ground the engine as well.
2. Insulation: EVERY time you pass a wire thru a
bulkhead or over a sharp edge, use proper insulation. Such as a grommet, or
similar. Especially on Mark3 it’s weary important as it’s only fitted with one
fuse.
3. Use the right size for the wire: The more power thru the wire the greater the area of
the wire. The same goes for length of wire. Minimum battery cable is 25mm2
and minimum alternator to battery is 6mm2. All connections to the
battery and generator should be properly crimped or even better soldered. If
the alternator wire comes loose with engine running, the charging voltage will
immediately raise to that level that the alternator will burn.
4. Check the charging voltage: It should read about 14,2volts, at fast idle. More
than 14,5volts, and the battery starts “cooking” dry. Less than 13,5volts and
it will start ”sulfurise” and thereby radically shorten the life of the
battery. Does the charging lamp shine? On a direct current (generator) system
the lamp can shine on idle, but should go out when the revs are raised. On an
alternating current system the lamp should go out almost immediately when the
engine is started, and stay off. An experienced specialist should handle any
reparation and adjustment on the charging system.
5. Fuses:
Use the right “size” fuse. A nail is never ok to act as a fuse. If the fuses
blow, check why, there is a reason to it. Check for short-circuits or an overload
to the fuse.
6. Poor starting due to lack of power: Could be a number of reasons. Check the charging. See #4 above. Do you have to top up the battery acid? Is the fan belt tension ok? If you get a
clicking sound from the solenoid but nothing more, a simple test is to give the
starter a blow with a hammer. If it works ok thereafter it is probably the
starter brushes that have worn out. If it starts ok with cold engine but power
seems to be drained with warm engine. It is probably the starter bushings that
are worn.
7. The battery: If not in use for a longer period, charge it and
store in a cold, dry place. Recharge every second month.
8. Positive or negative earth? As it is nowadays-negative earth as a standard, you
might consider changing your vehicle from positive to negative. The following
description has worked for me a couple of times. Detach the fan belt. Switch over the battery cables; remember to
switch cable shoes, as they are different size. Start the engine. Stop
the engine and mount the fan belt.
Start the engine once again, the charging light will flash a few times,
and then go out. Finnish. If you are
rebuilding from generator to alternator you are forced to use negative earth.
9. All electrical components that are involved in the
fuel system, mainly an electric fuel
pump, have to be connected via the ignition switch. Even better in series with
a safety switch.
10.
Use Your Head: It’s there for a reason. If you are the slightest
uncertain of what to do, ask. It’s better to be safe than sorry. You can create
havoc by doing it wrong.
Disclaimer:
The advice and guidelines given in these articles are given in good faith.
The owners and managers of the Galeforce Zephyr site will take no
responsibility for any injuries or loss sustained while carrying out the
described tasks and procedures or any consequences arising. Please read
the Safety First
Article