Date: Sat, 17 Apr 1999 09:39:36 -0700
Reply-To: Steven Johnson <sjohnso@JPS.NET>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Steven Johnson <sjohnso@JPS.NET>
Subject: Re: A/C HOT wires!!
In-Reply-To: <00f001be88ee$81893740$d431a2d1@dell>
Content-Type: text/plain; charset="us-ascii"
Bill,
What you've surmised is essentially correct. Over time, due to corrosion,
a small resistance builds up in the wire link between the electronic
components of the all the electrical systems of an any automobile. The
most suseptable area of this corrosion is at the connectors as they are
the most exposed and least connected sections of the wire. The small
resistance coupled with an a current and corresponding voltage drop
convert into a wattage which, depending on the amount of resistance, can
vary widely. The greater the resistance, the more voltage is dropped
at that point. So you get dimmer lights, a weaker horn or in the case
of the AC, less voltage to the component that you're trying to get current
to. That voltage dropping on the connectors to the relay/fuse in question
is getting hot because of the resistance in the connectors and the accom-
panying voltage/current drop associated with it. This generates a larger
wattage which, in turn, generates more heat. Indeed, if the connection
breaks down enough, it becomes a bigger heater. And, as you surmised,
eventually, it could be a potential fire starter. So, as others have
stated in posts that are now somewhere in the archive, the best you can
do is make better connections and use larger wires and they will better
conduct the current and will not damage the wires as quickly as the smaller
ones. I hope this clarifies the cause of the hot spot in your system.
At 09:22 AM 4/17/99 -0700, Davidson wrote:
>Okay. I found my 50 amp A/C fuse and relays.
>But the wires get so hot that I can only hold the large red one for about a
>second before it is too painful. Nothing looks fried, but these hot wires do
>not seem right to me. From a quick glance at the archives it seems I am not
>the only one with these hot A/C wires. I think I also remember some posts
>that report that fires have started here. The one solution that I found
>there suggested replacing the wire connectors on the theory that a small
>amount of corrosion inside the connectors would cause this heating of the
>wires. Any other suggestions?
>Thanks
>Bill
>90 Westy Syncro
>
>
Steven Johnson
Sacramento, CA
sjohnso@jps.net
| 
