Today's wire harnesses are pretty darn good compared to systems of the past. Fleets have options they have never had before, from sealed male 7-way connectors to sealed cable systems to sealed nose boxes.
However, no matter how good the harness system is, it must be protected at the front end. Without a sealed front end, corrosion and contamination will wick its way in, clogging the arteries of the harness and rendering the sealed harness virtually useless.
All metal sockets leak. So start by converting metal sockets to glass-filled nylon, and make sure they are insert molded. Insert molding seals the pins to the housing, preventing contamination from entering the harness system.
Next, use a molded plug-in socket so contaminants cannot work around the socket pins. It's amazing the turbulence created behind the cab driving at 60 mph in the rain. Now add snow and sleet, and the magnesium chloride on the highways has a way to work its way into every crack and crevasse on the vehicle.
Phillips has addressed this in a number of products, and so have competitors. However, when the fleet does not have these products in its trucks, what is the best way to maintain electrical systems before winter hits hardest?
First, get yourself a healthy handful of small packets of dielectric grease, and start your rounds of disconnecting all pigtails near the ground and insert new corrosion protective grease. Check where any rocks or debris may have damaged the insulation. Cut the wire and using a solder and seal or heat shrink, seal terminal and make a new connection. Consider new clear heat shrink terminals that are now available, as well as small to mid-sized torches that assure the technician has made a perfect connection.
Cable-tie or secure all dangling pigtails as close to the lamp as possible. You don't want to give road ice a place to start building up, inadvertently disconnecting pigtails from the lamps. Another neat trick is to use one of the gladhand seals with a dust flap on all entry holes going to the stop tail directional lamps. Where small wire entry holes are used through the metal frames, find yourself small grommets, cut a side, then insert the wire through the grommet and attach the grommet to the frame.
Where heat shrink terminals are not available, heat shrink tape is another option. Simply cut a short strip and wrap around the defective wire. This tape cures in the air after a short time and will give a great seal.
Now that you have protected the lighting and wiring system, apply a healthy amount of dielectric grease on all 7-way sockets and plugs. Of course do this after you have brushed and cleaned all contacts with brush devices made for cleaning contacts.
While you're at it, check the battery cables. See-through battery cables are available in clear, translucent red and light grey. These help spot corrosion before it gets to the point where alternators and starters are adversely affected. It's an easy and inexpensive maintenance fix.
Bob Phillips is President and CEO of Phillips Industries. Phillips also offers a library of tech tips on its website at www.phillipsind.com.
Corrected to reflect correct name and title of the author.