eyeteeth wrote:
I have been printing the information off to reference later... Good info.
I finally had a chance to do a little testing on my DC problem, and have narrowed it down to one wire. Unfortunately, the 'hot' seems to have shorted out somewhere.... Dang it. There is maybe a foot of it visible before it disappears into the wall and routing to the opposite corner of the RV. Taking suggestions as to what might be the best way to get a new wire to the destination. Anyone with experience with this?
It's more likely a break in the wire if you're not blowing fuses/circuit breakers. (It could be a unprotected circuit, in which case the wire will be getting very hot and may act as a fuse by burning up.)
Leeann's suggest is probably best. However, what I do if I want to still use the same routing is use the old, suspect wire as a "fish" tape. Firmly tape the new wire to one end of the old wire and CAREFULLY use the old wire to pull the new wire through the confined spaces.
I emphasis carefully because, if the wire is indeed broken, the insulation is the only thing holding the length together. Also, you're probably going to run into considerable resistance as you pull the wire around corners and through tight spaces.
If the old wire comes out without pulling the new along with it, you pulled too hard or the wire was completely broken, insulation and all. If the wire was on an unprotected circuit, an actually short may have caused the wire to burn through.
Melted metal and charred, blackened insulation is evidence of a short-induced melting. Discolored insulation by itself might indicate current was kicking off heat trying to jump across a small break in the wire, especially if the insulation is otherwise intact.
If the new wire doesn't follow the old wire, you'll have to use an actual electrician's fish tape or, more likely, follow Leeann's advice.
When you get the old wire out, examine it for abrasions on the insulation that indicate it was rubbing against a sharp edge, eventually leading to a short. (2004 Chevy 2500HD Silverados is one case i know of where this is a known manufacturing problem/defect.) In this case, you'll want to reroute the wire if you can't get at and fix whatever is causing the abrasion.
In any case, it'd be a good ideas to make sure the circuit is protected by a fuse or circuit breaker. With the exception of some parts of the starting system, every circuit should be protected. Best practice, as codified in current marine wiring standards, mandated a fuse or circuit breaker within seven inches of the circuit's power source.
I'll explain why parts of the starting system are exempt from circuit protection in my next post.
