A Dodgy Volt Meter

During the survey sea trial we observed the port volt meter reading low. Kevin Ambrose from Diesel Systems was onboard and quickly checked the alternator output and verified the voltage was fine. We also observed the voltage on the fly bridge gauge was reading the correct voltage. Based on that, we have an entry on the survey indicating a faulty gauge.

Today while ‘relaxing’ in the slip, I worked on a couple small projects to continue getting her ready for cruising. One of these was this ‘faulty’ volt meter.

Pilot house instrument panel ready to tip forward.

I carefully tipped the panel forward trying not to put any extra strain on the wiring I knew would be attached. What I found was encouraging and left me feeling a little smug.

Back of pilot house instrument panel

I immediately noticed a number of loose bolts and wire harnesses that were falling off. Looks like wires must be the problem with the gauge…. Well, I tightened up all of them and gently bent the small slip-rings inside each of the wire harnesses to be a little tighter and put everything back together thinking that was a super easy and free fix! Just to be sure I’d really figured it out, I decided to fire up the mains and check to see what the gauges were reading. Imagine my surprise when the dodgy volt gauge remained dodgy – no difference from previous behavior. Well, I figured it must be a faulty gauge but thought since I had the instrument panel open already, I may as well test to make sure. Using my multi-meter, I first checked the voltage on the working gauge and then the dodgy gauge. They read the same – one more mark for a faulty gauge. Just to be sure, I decided to switch the wiring harness from the bad gauge to the good gauge – I expected the good gauge to read where it had previously – it didn’t! So, I have the port harness connected to the starboard gauge and it’s reading low. One more verification – I plugged the starboard harness into the port gauge and it reads exactly where it should.

Now I’m a little stuck – It appears the signal from the port engine isn’t correct as it has the same output on either gauge but, the voltage was correct when tested during the sea trial and the gauge at the fly bridge shows a full 12V.

I guess we’ll investigate further when we haul out on 13 June for deeper repairs and modifications. I’ll have several posts dedicated to just that work as it’s going to be significant.

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