View Full Version : "Hot" wire...

06-05-2005, 08:17 PM
I am in the process of wiring up my new aftermarket alternator and when I came to the four-way connector that attached inline to my battery positive cable, I noticed that the double brown wire that connects into one of the four spades is "scorched". These two brown (hot) wires feed one to the ignition switch and the other to the fuse box that feeds all my lights. The only thing non-original that feeds from these wires is the halogen headlight bulbs. My halogen fogs run off a circuit completely independent of the wiring harness. This is troubling because it indicates to me that there might have been some kind of overload on the system. Everything works normally and the new alternator has yet to be hooked up. Does anyone out there have any ideas? Could it be a short in the system that caused the overload? The wires are all good but the cover on the spade is charred and the insulation on the wire is melted back about 1mm.


06-05-2005, 09:12 PM
Is it possible that I answered my own question? I cut the "burned" connector off and replaced it with a new connector. This time, I not only crimped but soldered the connection and covered it with shrink tubing. The charred connector was extremely corroded, with the copper wires "rusted", heavy green corrosion. Could a heavily oxidized connection cause the thing to overheat and char the insulation? Piman, wherefore art thou??


06-05-2005, 09:49 PM
A friend of mine with a 1974 TR6 put in an extra fuse box on top of the horizontal shelf just above the starter. This fuse box is fed from the battery then a 30 amp fuse feeds the starter switch. That large burned brown wire is a common problem with the tr6 and the extra fuse box seems to make sense.

Geo Hahn
06-05-2005, 10:03 PM
...Could a heavily oxidized connection cause the thing to overheat and char the insulation?

[/ QUOTE ]

It sure could. A loose connection will also do this, especially on a circuit with a high draw like one of the spade connectors on the back of the headlamp switch (that one happened to me).

06-06-2005, 09:49 AM
Had the same thing in my ol' 62 VW bug. I chased poor lighting and weird electrical things for years before finding a charred connector that was not much more than carbon (still shaped like a connector) on top of the generator-- couldn't tell because of the insulator! replaced the connector and wire and bright lights and no more funny noises in the radio!

06-06-2005, 10:53 AM
Hello Bill,
I'm still around, but the answer has already been given, yes a poor connection heats up. And it doesn't need to be the cable into the connector, the connector itself can do the same. With push on connectors this starts a vicious circle as the heat takes the tension out of the connector nad the problem gets worse, particularly with high current connections. As a matter of interest, at my work, we regularly use an infra red thermal camera to check switch panels for 'hot' connections as regular maintenace and warning of potential problems.