Wiring corrosion

[triumphrick]

Just installed a new Eagle FishElite 500c yesterday and had an interesting problem. This unit replaced an older unit that had not been used for some time, however the power cable was run and stubbed out at the proper location. Used my trusty Fluke and she read 12.8vdc. Cut the old power plug, wired in the new, finished gps and transducer and powered up. No power, just a quick raster and no image. Checked voltage again, still 12.8vdc. Went to tech support web site and warned about using old wiring. Suggested new cable to battery with a 3a fuse inline. Thought WTH and ran new wire. System powered up just fine. Traced old power cable to fuse block waaaay up in top of center console with corroded connections. Seems as tho the volts were there but would not handlethe current once powered up. Go figure:redface:

 

[JB]

Re: Wiring corrosion

Happens a lot, Rick. Mostly in battery cables where the resistance is small enough that it doesn't measurably affect voltage measurements when the circuit is open or there is only a very small load, but when the load wants lots of amps (milliamps in your case) that small resistance drops all, or most, of the voltage and the load thinks there is no voltage there.

Good call by the Lowrance Tech Support guy.