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dc electrical question

Posted: Wed Jan 02, 2008 1:07 am
by edbush
Spent some time running down electrical stuff on the new boat today. I'm not having too much luck in getting anything DC to operate. Batteries are fully charged, but it seems like everywhere I checked with a volt meter, I'm only getting about a reading of about a 1.5 volts. Dome lights, shower pump, a few other places and I keep getting the same 1.5 reading. Checked all the fuses and they're ok.

Any thoughts?

Thanks,
Ed

Posted: Wed Jan 02, 2008 6:50 am
by RWS
Look for a possible bad ground.

Check the ground system for resistence with an ohm meter.

If that's not it, on the positive side, start tracing down where you loose the voltage.

RWS

Check battery cables

Posted: Wed Jan 02, 2008 7:29 am
by TADTOOMUCH
Check battery cables for corrosion and also for corrosion on terminals. Start at battery and work your way out towards dome lights etc. checking each connection for missing ground or bad connection.

12.5+ VDC?

Posted: Wed Jan 02, 2008 4:19 pm
by rossjo
12.5+ VDC at the battery terminals?

Volt meter

Posted: Wed Jan 02, 2008 4:32 pm
by TADTOOMUCH
What type of volt meter do you have? Digital or analog? Does it have an internal 9V battery that may be old? Sometimes that will make the meter read low. Have you checked it with another meter? Will the battery start the motor or crank it easily? If not then the battery may not be taking a charge even if you had it on a charger for a while. Might have a dead cell.

Just a few things to check.

follow up on volt meter and batteries

Posted: Wed Jan 02, 2008 11:12 pm
by edbush
Thanks for the input guys... By the way, I'm working on my 1973 F36 Tri-cabin. I am using a brand new digital volt meter with new battery. The house batteries are located under the floor of the salon next to the generator. There were NO cranking batteries connected at the time I checked the voltage on the dome lights and shower pump. Would that effect the ground? Are the house and cranking batteries normally connected somewhere? The onboard charger seemed to work well. When I first started the voltage check, the batteries read only 2.7 VDC, but after a couple hours of charge both house batteries (parallel wired) read a little over 12 VDC. They seemed to charge easily and hold charge.

It was suggested that I start at the batteries and work my way back to the dome lights, etc., but my question is this: Will the power supply run directly from the batteries to the power supply/panel located behind the sliding door on the starboard side of the boat and then to the lights, etc.? There are labeled fuses there for the dome lights, and all other DC components. I'm a bit apprehensive about taking that panel down, as it has both AC and DC breakers, wiring, etc.

Thanks in advance for further help! If all else fails, I'll just rewire the dome lights and other DC equipment with appropriate fuses, etc., and bypass the original electric panel. That is NOT my preferred method, however!

Ed

Anyone have an electical diagram for a 1973 F36 tri-cabin?

Posted: Wed Jan 02, 2008 11:14 pm
by edbush
By the way, do any of you have a copy of the electrical wiring diagram for a 1973 F36 Tri-cabin? If you do, could you email a copy to my address below?

Thanks,

Ed Bush
edbu59@yahoo.com