all batteries dead

[RHJ]

Hello All . My daughter is the proud owner of a 1983 aft 3207..twins..I am helping her get things up to speed. The fresh water pump has failed and I am thinking of replacing it with a Shur Flo 4008 -101 - E65. The failed one is a Shur Flo 2.8 gal 4 amp. Should I expect any problems..? We also have a Battery charging issue. There are 4 24ms class batteries . 2 are labelled as start. One will charge off the on board charger but drains quickly to .3 volts dc. Obviously defective. When running the engines and measuring battery voltage with a Fluke voltmeter, a max of 13 V.D.C is measured. Shouldn't 14v dc be available for alternator output or is a high charge current which I can't measure dragging the voltage down?. I am hoping that once the defective battery is replaced the alternator voltage will increase to 14...ANY input is appreciated,

Thanks,
RHJ

[waybomb]

13vdc is too low, but your bad battery could be pulling the output down.
I;d pull all the batteries and have them load tested. Or try to borrow one so you can test yourself in the boat.

[Viper]

Welcome aboard. You may get more help if you started another thread.

Be careful when replacing the pump with one that draws a higher load. You need to make sure the existing wiring can handle the extra current for safety reasons. Double check but I think the new one you're considering is almost twice the amperage draw.

[RHJ]

Thanks waybomb and viper...

The current draw on the replacement pump is 5 vs 7.5 amps .. # 14 wire to existing pump.
Please help review the battery setup. There are presently 4 -12 volt 24 class batteries.... 2 are marked start ( 1 and 2).. Other 2 are unmarked. All 4 charge off the built in charger when at shore. When the engines are started , are only the START batteries used? Does the battery switch on the panel ..1 ..2 or ALL only switch the START batteries. Are the unmarked batteries only for accessories?

Thanks,

RHJ

[km1125]

Source of the post Thanks waybomb and viper...

The current draw on the replacement pump is 5 vs 7.5 amps .. # 14 wire to existing pump.
Please help review the battery setup. There are presently 4 -12 volt 24 class batteries.... 2 are marked start ( 1 and 2).. Other 2 are unmarked. All 4 charge off the built in charger when at shore. When the engines are started , are only the START batteries used? Does the battery switch on the panel ..1 ..2 or ALL only switch the START batteries. Are the unmarked batteries only for accessories?
Thanks,
RHJ

There can be a hundred ways to wire up the batteries. I'm guessing your two unmarked ones are connected in parallel and are considered the "house" batteries. I would guess that the battery switch is only for the two start batteries - HOWEVER, they could also be wired in parallel and then the 1-2-both switch would switch from the "starting" batteries to the "house" batteries.

Sometimes you need to do some digging to find out exactly how it's wired. You can take off each one of the positive battery cables at a time and see what stops working, with the 1-2-both switch in various positions. Make notes when you do this because it can be confusing. If you do disconnect stuff for these tests, MAKE SURE that it is still insulated and protected from inadvertantly touching any other metal and creating a short circuit.

[RHJ]

Thanks First Mate:
Looks like that is the only way to do it...hard to follow the wiring leaning in ....
RHJ