Voltage meter

[Pedro]

My 1996 Albn 28 with the Penninsular original engine and gauges, has a very intermittent and always very faint (hard to read )digital hour meter. I've had the system checked by two different mechanics,Alternator is putting out 14+ volts,Batteries show 13.9-14.2, but gauge on dash and Garmin both read 12.6-12.8, nothing higher,Sytem operates as normal on 4 days at a mooring,starts right up,house battery 8d doing its job,starting batts seem to hold their charge very well,I'm guessing a bad connection somewhere between the battery bank and panel,where to start?one mech wants to run a new heavier wire from battery bank to panel, and stop guessing,

[catalina_mike]

In my 99 the place to check is behind the bathroom. I'm assuming the common element is the buss bar that is fed from the battery switch below the step. The connectors they used can have oxidation and create resistance lowering the voltage. Check it there and look for connectors that are discolored. That will be your issue...

[Pedro]

Thanks Mike, There is a lot of green oxidation on the buss,What's the best way to handle that?

[catalina_mike]

New ends... Cut the wire and redo the ends. If the wire is not long enough add a terminal strip to extend the wire or splice. The other option is to pull a new wire. Mine would not be that bad to do.

[denchen]

there is some proper grease made for battery terminals that slows or stops oxidation. Mine came in a small silver paper satchet that you snip off one corner. Its cheap to buy and goes a long way as you don't` need much. Its also useful for the battery terminales

[Russell]

I have had good luck using an electrical connection spray cleaner such as the one made by CRC available at auto supply stores. With the batteries off you can spray the buss and use a toothbrush to clean up the green deposits and some you may have to disconnect and clean with the spray. Intermittent toggle switches on lights, etc. work perfectly after spraying with the cleaner. After the buss is clean and everything reattached, spray it with something like Boeshield T9 or Corrosion X.

[Pedro]

So all the black wires (-terminals) on bus bar are Green,I'm going to take them off one at time and clean,I'll save remaking ends for lay up as I have a bad history with fine electrical work,I'm more of a hammer and chisel type gut,lol,,

[socalmike]

Woolley wax. You will be shocked how it cleans and coats wiring.

[Panhdjoe]

The Voltage drop you have is to high for operation of The electronics and gauges, no more than 3% in recommended. Yours is over 10%. The problem could be in bad connections but my money would be on wire size. Voltage drop in the circuit is dependent on Current flow (amps) length of run (including ground side) and wire size. Manufactures often run wire to small for loads or owners install extra loads. They are lots of charts on the internet for wire size based on length or run and current flow, don't forget that the length of run includes the ground return, if the helm is 6 feet from the battery bank the length on run is 12 feet. When pulling new wire pull double red and black, or yellow. (some new boats are using yellow for DC ground). My guess is that #10AWG wire would do and you can say goodbye to that big voltage drop.

[Pedro]

Thanks,That's exactly what my mechanic suggested,I'll attemp it over the winter,

[Pedro]

The theory of wire size is logical, however, this problem just sort of worsened over a season or so, slowly the readings slipped lower and lower even though the alternator readings and batteries were reading 13.6-14.1 or so , so it really seems like corrosion but I like the idea of upsizing wires and making fresh connections as I go ,since we're now talking about a 20 year old boat, with lots of original parts engine,tranny ,gauges etc, the "beast" starts,runs,doesn't hardly smoke just want gauges to be accurate,

[Pedro]

So I used the crc contact cleaner, it got some of the green off, I loose and reconnected the grounds, went fishing yesterday and for the first time this season the gauge on the garmin read 13.3 volts then down as low as 12.9, but that's a start! I'm definitely on the right track!

[Carl]

If you are going to go through all your connections and cleaning them, do yourself a favor and apply some of this product before reassembly. Its cheap and very good. We have used this product for over 2o years in the transit industry, trains, and it lasts until you wipe it off years later. Overtime I take a connection apart, I apply some, especially battery terms. No more "green".

http://www.sanchem.com/electrical-conta ... icant.html

[Pedro]

Thanks I try it,