Preventing
fires
The standard wiring
harness in the 2CV is dangerous. The wiring harness is attached to the
air cleaner bracket with a steel clamp. This clamp has very sharp
edges. After a while the clamp cuts trough the insulation. Now it is
only a matter of time before the steel clamp finds a live wire. The
wire will short circuit and the wiring harness catches on fire. This
can be avoided by protecting the wiring harness against the clamp with
a piece of rubber wrapped around the wiring harness i.e. some old
inner tube.
Keep an eye on the live wire from the alternator. The nuts must be
tight and the wire ends must be good. If the nut rattles loose the
cable end will vibrate on the bolt. The alternator delivers a high
current (30 A). If the wire isn't connected proper you will have
sparks firing between the connecting bolt and the wire. This eats away
the thread and the wire end. Even worse if this wire falls off and
touches ground - this will short circuit the battery via the blue
wire. This wire will start to glow and immediately vaporize the
insulation. The wiring harness will be destroyed and you may start a
fire.
Also the battery holder should be checked closely. The genuine
battery has a holder for the regulator. If the battery has to be
replaced there is no real reason to buy the genuine part. You can get
much cheaper batteries that have a higher capacity. The holder for the
regulator is missing but it is not a problem to mount the regulator in
a different place. The battery may have different dimensions, so the
holder doesn't fit perfect. The new battery can still be kept in
place, but the holder can slip up and may touch the + terminal. As the
holder is connected to ground you will have a short-circuit that may
start a fire. Again this can be avoided with a piece of an old inner
tube that protects the terminal.
There are different reasons for the motor to catch on fire.
Apparently the heating tubes cause the biggest
problem, mainly the one on the passenger's side. After some
years the ends of this tube will fray. So it doesn't stay in place any
longer. It will slip down right onto the muffler. On a longer trip the
muffler becomes very hot and will set the paper and foam tube on fire!
Once the tube is damaged on each end it won't help to tape the ends
or use clamps. It will fall off again. In that case better replace the
tube. The universal tubes from after market sources are not good. The
best choice is to use a genuine part. But be careful - you may find
the genuine tube too long. Don't take the old tube as a sample - it
was already too short. Make it long enough to fit proper. In addition
the tube must be attached to the heater cable or the wiring harness to
keep it from falling down. You can use a long cable tie for this job.
Inside the hood you will find an insulating mat. The reason for this
is not only to supply nesting material for mice and other rodents- it
also sucks in oil and fuel. After some years it will be soaked with
these liquids. There is no danger as long as the surface isn't
damaged. But once the surface is destroyed the mat starts to
disintegrate. Pieces will fall down on the transmission, the motor and
the muffler. It is easy to imagine what will happen to these oil
soaked pieces on the muffler. So it is better to remove the entire mat
once it starts to disintegrate. The reason for this mat was to absorb
noise from the motor. In my book it is more important to avoid fires
than reduce the noise level just a little. And after all these mats
are available as spares.
Carburetor fires are mostly caused by backfire. This will appear as a
"plop" from the motor. The reason is mostly a too lean
mixture, a bad adjusted timing and/or valve settings. The mixture
already ignites before the inlet valve is totally closed. This will
send a beam of fire back through the manifolds into the carburetor.
Normally this doesn't matter. It won't set the carburetor on fire. But
if this beam of fire reaches the air cleaner it might set the oil
soaked foam on fire. If this happens while driving you won't realize
it for a while. The motor works normal and the fire get lots of
oxygen. Then the plastic air cleaner unit catches on fire, and the
burning plastic is blown all over the motor. If the reason for
backfire is bad tuning of the motor it can be solved very easy. Adjust
the ignition and the valves regularly. This should solve the problem.
The fuel line can also cause problems. Very critical here is the
connection between the fuel pump and the carburetor. As soon as the
reservoir in the carburetor is full, the needle valve will close. But
the fuel pump continues to pump. This will create a pressure in the
fuel line. If the connection on the carburetor (less likely on the
pump) doesn't sit tight, fuel will escape. You can see this at the
carburetor. If it is mainly covered with dust and dirt except an area
around the inlet then the tube may not be tight. The fuel line is
rubber and after some years the material will harden. When the rubber
is no longer flexible more cracks will appear. If the fuel pump puts
pressure onto the line it may burst. When fuel escapes it may reach
the muffler and ignite. If it doesn't ignite you still have the risk
of a fuel - air mixture. One spark may ignite this. If you realize
there are cracks in the fuel line replace it immediately. |