12V DC Electrical Systems – Keep Them Clean, Bright & Tight

I’ve been having trouble with an old Ford F-150 trick I’ve got.  I don’t use it regularly and frequently when I try to use it the battery is “dead”.  After I plugged it in, I looked into it the problem wasn’t really the battery.  When I took off the cables and hooked the battery charger directly to the battery it was something like 85% charged.  This led me to take a closer look at the positive cable (I’d already replaced the negative). I probably should have given the car to Maz Tech Automotive instead of dabbling with the components myself, but old habits die hard.


If you look closely you will see a crack in the terminal clamp.  This is made of lead and it is soft enough so that when the nut is tightened it forms a tight contact with the battery post.  However since this one was beat up and cracked it would not form a tight connection.  For low voltage connections it is important to keep them “Clean, Bright & Tight” or you will have continuous problems.  This one kept corroding because it wasn’t maintaining a tight metal to metal connection.  This increased the resistance to the point that the current flow wasn’t enough for the truck starter to turn.


To fix this it is a simple mater of cutting off the old one and attaching a replacement terminal clamp, available form any auto-parts store.  Notice that this one has two heavy gauge wires cast into the connector.


However it takes a bit of effort to cut cable this thick with regular wire cutters.  There is a set of cutters with curved jaws and a longer handle that makes cutting this size wire feasible.  If you don’t have a pair of these try taking smaller bites out of the cable and maybe you can work your way through the cable.

The image at the top shows the finished project.  It only took about 10 minutes and the job was done.  If I’m correct in my troubleshooting then this should stop my problem.  You should consider checking your battery terminals every fall before cold weather sets in (assuming you live where it gets cold).  It takes more current to start a car in the cold and if the connection is loose or corroded then you might find yourself stranded in the cold.

Author: Jerry Ward

Working on creating a 10 acre urban homestead in S.E. Michigan. To pay the bills I work as a product manager/business analyst in the IT field. Now the admin of Save Our Skills