Wiring Faults

This technical page includes tips for curing a wirting faults

The fuses on my car keep melting, is there a fault with my lights? I have checked the bulbs and they are correct.

When the Escort was originally built it would have been fitted with what are called continental or ceramic fuses. These are the familiar plastic slug with a strip of fusible metal clipped over one side.
Now as the name suggest these were made from a heat resistant material, if not ceramic then a tough thermosetting plastic (doesn’t melt) that would endure the heat required for the fuse to blow. Unfortunately for us the modern cheapo replacements are made from thermoplastic (it melts) and the fusible metal is very low quality, the resulting fuse offers less protection and causes the problems you are experiencing. You should also be aware that these fuses only protect you from fairly heavy shorts rather like a slow-blow fuse, for example an 8 amp fuse will carry 11-12 amps before failing but may begin to heat up and possibly the metal will stretch. If your fuses are melting in the middle therefore I suggest you either fit the next size up or, preferably, hunt for better quality fuses. Try your local Lucas dealer.

More worrying is if your fuses are melting at the end, this could indicate that the heat is caused by a poor connection between the fuse and the fusebox blade. The blade at the front of the fuse is rigid, the one at the back is sprung but if corrosion weakens either, then the fuse can be loose. Corrosion itself can cause a poor contact. Both can lead to heat being generated between the blade and the fuse, causing the fuse to melt. More worrying still is that that the heat also damages the fusebox itself (the blades become loose) and the wiring loom multiplug below (the moulded casing melts away exposing the female bullets within).
Given the poor quality of modern fuses, I prefer to bypass the existing fusebox with a new unit fitted with BLADE fuses; not only do these give better protection from overcurrent but also there is a far greater choice of current values. Depending on how bad the damage is you could keep the existing wiring intact by feeding male bullets into the multiplug and bridging short lengths to your new fusebox (I advise using exclusively 27 amp cable for these short lengths) fitting the fusebox close by, say to the wiper motor bracket or the glovebox if you have one. If the multiplug is damaged however then cut it off and use either good solid crimps or solder and heatshrink tubing to join short lengths to your new fusebox, which should contain at least 12 fuses! One for EACH dipped beam and main beam plus a couple of extra ignition and permanent live fuses for your accessories, perhaps even your driving lamps.

The author cannot accept responsibility for any claims arising from matter included in this text. As with all electrical matters, if you have any doubts contact an auto electrician BEFORE starting the job.