Your Five Dollar Insurance Policy

If I told you you could purchase an insurance policy that would protect your British sports car for as long as you owned it, for around five dollars, you would probably ask me if I also had a bridge to sell! While I don’t have a bridge, I can tell you how to protect your baby for under five bucks.

Most British sports cars manufactured before 1969 have only two fuses protecting their entire electrical system. Typically, these fuses only protect the horns, A-2 (the purple wires on the fuse block), and the accessories, A-4, (the green wires on the fuse block). Having a fuse on the horns is handy when the horn button sticks and your neighbors are threatening, and your accessories such as the stop lights, turn signals and wipers, etc. are duly protected from staging their own version of the Chernoble meltdown.

Some of the most important and largest current-using circuits are not protected from electrical problems and short circuits. The circuits that I’m referring to are (surprise!) the headlamps and sidelights. These circuits are in constant use, unlike all the others that enjoy only intermittent use. A worthwhile modification to pre-’69 British sports cars is to fit fuses to these unprotected circuits. This will protect the car’s wiring system from damage and the whole automobile from a possible fire.

When an unfused circuit (like that of the headlamp) develops a short circuit, the wires will get red hot and burn away their plastic insulation. Should these bare wires contact anything combustible, such as interior material, grease or gasoline, you can guess the results—you do carry a fire extinguisher, don’t you?

An easy way to protect yourself and your British baby is to fit what is known as an “inline fuse”. An inline fuse is a small plastic holder containing a replaceable standard automotive fuse for attachment in a circuit.

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These little wonders are usually placed between the switch and the electrical device in the wiring. For example, on the headlamp circuit, put the fuse between the headlamp switch and the dipper switch, for the marker lights, between the switch and the group of red wires. Or, a single fuse can be placed between the headlamp switch and its source of power, on cars with separate ignition and headlamp switches. Personally, I prefer to protect each circuit with its own fuse. (See above diagram.)

The best thing about inline fuses is that they can be easily installed, and also, easily hidden for you Concours enthusiasts. If a problem arises in that circuit, the fuse will blow, avoiding any further damage. You’ll also know that the problem is limited to just that one circuit, not the whole car when it comes time to troubleshoot the problem. Moss stocks these inline fuse holders under part #146-750. Use a 25 amp fuse, #146-710 for most circuits or a 35 amp #146-700 fuse if you’re using Quartz Halogen headlamps.

To install an inline fuse, first consult your shop manual for the wiring diagram. This will show you how the circuit is wired and the color code of the wires in question; then DISCONNECT THE BATTERY, otherwise you will be cutting into a “live” wire. While there isn’t enough voltage to hurt you, you want to avoid any short circuits while you install the inline fuse. Be sure to solder or use the proper type of connectors when joining wires together, just twisting them together and slapping some tape around them only creates problems, not prevents them.

Often, you can simply cut the existing wire from the switch and install the inline fuse in the middle of the wire, leaving enough distance from the switch so you don’t have to stand on your head to change the fuse.

If the wire isn’t long enough to handle easily, it is alright to extend the wire using additional wire of matching size and approximate color. Installation is as follows: Cut the wire in a handy location between the light and its on-off switch; then remove about 3/16″ of the insulation from each end. On one end, slide on the plastic cap, followed by one of the metal contacts, which you will solder to the end of the wire. On the other loose end of the wire, slide the longer plastic tube on, followed by the spring and the other contact that you will solder in place. Then insert the fuse in the longer tube and screw the cap in place by pressing down and turning it about a quarter turn. The job is done. It’s a good idea to mark the outside of the fuse holder with a felt tipped pen so you can tell the circuits apart. At $1.55 each, you can afford to protect all the unfused circuits in your car and ultimately your car itself!

 

By Ben Travato



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