Do It Yourself

Hot Tips:

The number one piece of equipment needed is a good test light. Hook one to any ground and check for 12 volts on any wire or connection. Hook the end with the ‘alligator clip’ to positive (for instance on the “+” side of the battery) and check for any ground.
This tool will save you hundreds of dollars in repairs, without it you will have a very difficult time finding electrical problems. Electricity is invisible and you will be guessing on everything unless you are able to use a test light. Buy one and keep it on board. Just because you don’t know how to use it doesn’t mean a friend won’t.
The same applies for a good complete $100.00 tool box. Keep them in good shape and maybe your friends can help you out!
Start with the battery. Check with the test light to make sure everything is working right. Then attack your problem with the test light in the same manner.

Some Wiring Basics:

Standard colors for boats since 1980 are as follows,
  • Heavy red 10 gauge (main battery)
  • Heavy black(main ground)
  • Purple (ignition)
  • Yellow (starter solenoid)
  • Grey (tachometer)
  • Brown (temperature)
  • Blue (oil pressure)
  • Brown with stripe (alarm)


  • Pink (fuel sending unit)
  • Yellow (blower)
  • Brown (bilge pump)
  • Grey (navigation lights)
  • Heavy green (bonding wire)
  • Red (misc. Electrical Add-Ons, VHF, Depth Finder, Stereo, Radar, Power Supplies)

Common Problems:

  • Check to see that the acid (electrolyte) level is up to the plastic liner inside holes and the fully charged specific gravity is 1.25 to 1.30 in each cell. (A tester can be purchased for less than $ 6.00)
  • Be sure that top surfaces stay clean and dry or they will slowly discharge the batteries.
  • Check that all connections are tight with a pair of pliers or wrench, finder tight is not good!
  • Check to see if the engine cranks properly for 10 seconds with each battery alone. Ground the ignition coil wire to a safe place and check for any gas fumes prior to checking, then crank the engine over so it won’t start but only turn over.
Check that all of the battery cables are in good condition and that the connections are clean and sealed from moisture.
Fasten all batteries down tight. They can cause a major disaster if they come loose in bad sea conditions. Fire can result.
Replace any battery over 4 years old as it will only lead to trouble in the near future.
Affordable Marine Service will get your boat in good running order for the season. We service all of the various engines and outdrives. Feel free to give us a call @ 619.578.5979 to schedule an appointment for an estimate.