On most cards there are several fuses which will blow and prevent an electrical fire in the event of a fault. This is not the case with the Triumph Dolomite range as they only have two fuses. All triumphs and most other English cars share the same colour coded wiring systems of which the more important of these is explained below.

The Brown wires are connected directly to the battery and are used as main feeds from the alternator and to the ignition and headlight switchs. They are never fused because of the high current flow in these wires. Most items attached to them are individually fused for safety reasons, imagine blowing the fuse for the ignition or the headlights going around a sharp corner during a bad storm !! The White wires are unfused battery after the ignition switch, these are used exclusively for the ignition and other warning lights. Again these should never be fused because of there importance. It should be noted that there are very few Brown or White wires used in any Triumph.

Attached to one of the White wires is the first fuse which feeds the Green wires which in turn supply power to all those things that operate when the ignition is turned on such as the blower fans, gauges and indicators.

Attached to one of the Brown wires is the second fuse which feeds the purple wires which in turn supply power to all those things that operate all the time such as the horn and interior lights

As you can imagine these green and purple wires run all over the car and the chance of an electrical fault is very high.

One of the unfused brown wires feeds the head light switch which switches power to two circuits. One of which goes to the headlights via the dipper switch. This circuit is never fused for safety reasons however on stags four individual fuses are supplied for each of the headlamps which is a good idea but is difficult to install and causes other problems with voltage drop to the headlamps. The second circuit from the headlight switch is the problem maker in Dolomites. This circuit is used to feed all the tail lights, parking lights, number plate lights and instrument lights including the gear indicator on automatics. A total of 14 items all over the car are connected to this single circuit, it is by far the most over used circuit in the car and it is also unfused on Dolomites. I have come across several Dolomites with badly damaged wiring harnesses caused by a fault in one if these little light citcuits. All these little lights are connected to one single Red wire comming from the headlight on/off switch.

Fitting an inline fuse to the red wire comming from the headlight on/off switch will prevent an electrical short from destroying the cars wiring harness or worse still catching on fire. The fuse holders can be obtained from any auto accessory store and fitted in a few minutes and could save your pride and joy from extensive damage caused by a very simple electrical fault.