Michael Boyle (Bellmere, QLD)

My 60 Series ‘Herman’ has been with us for a couple of years now and has a TJM bulbar, roof rack, Kaymar rear wheel carrier, snorkel, 2in Tough Dog suspension lift and 33in Maxxis Bighorns. I want to do front and rear auto lockers and a winch. I want to be able to go everywhere! The wife and I are going to eventually drive around the country doing the iconic 4WD tracks.

Sometimes the charging light and air cleaner light come on while driving and the alternator gauge moves up to around 16 volts when doing about 100km, but comes down once it’s idling. I have changed the alternator, but no joy. I think it must be bad earth or loose wire, but don’t know where to start? Help me please!

Allan

Well Mike, you’re onto the thing yourself I think, you’ve got to earth everything. In particular if it is a diesel. I would also earth the Edec control motor, that’s the little solenoid that clicks, with a rod going backwards and forwards when you turn the ignition on and off. They have a tendency to corrode, so fit an earth strap from the top of that to the engine block.

You are certainly going to need a body to engine earth, but earth everything except the radiator otherwise you will get corrosion and all sorts of problems with that. You can also get a voltmeter and see what its reading from earth to the battery and earth the block, you should only have half of a volt between the two, with voltmeters you allow a 0.01 of a volt for bolted connections, 0.01 of a volt for a meter of cable, 0.02 of a volt for spring loaded connection, but anything over that is excessive.

If there is a fuse between the main feed cable from the alternator to battery, I would also replace this, they sometimes develop high resistance. I’d get the terminals off the battery and clean them up with a mix bi-carb soda and hot water usual works best, use some emery paper to clean the terminals and bolt them back on again. And you will fix the problem.