Reconnecting Batteries, Isolator and Switch. Just want to be sure.

[MexTex]

I am installing two new batteries in my 09 22ve and I want to make sure that I am connecting everything up correctly.

Isolator: (B1) to Positive Post Starting Battery, (B2) to Alternator and (B3) to Positive of Deep Cycle Battery
Factory On/Off Switch: One Post to Starter and the other post to the Positive of the Starting Battery

Engine Ground to starting negative terminal and then daisy changed to the negative of the deep cycle.

IMG_4392.jpg

[chpthril]

That takes care of the large main cables. Amps and helm BUS connect to house battery. small brown auto bilge can connect to either battery B+

[MexTex]

Looks like everything is connected appropriately, but for some reason when the switch is placed in the on position: the engine is not starting, the display is lighting up but is showing a blank screen and I here ticking.

When I put the plunger on and started the boat up a few days ago, she was slow to crank up (sounded like a low starting battery), but I was able to start the engine and run it for 15 minutes or so. I shut the engine down and tried to restart it, but could not. Didn’t make since to me because by that point I figured the alternator would have charged the engine a bit. I returned home and charged the starting battery separately. Once fully charged I tried to crank up the engine again, but same scenario. Could the isolator have gone bad?

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[chpthril]

15 mins run time would do little to a dead battery and nothing for one thats given up the ghost. A good charge will bring up a dead (run down low) battery, but again, do little on a bad battery. With a suspect battery, I would not rely on the charger to tell me the battery is charged. I would want to see its actual at-rest voltage level AFTER the surface charge has depleted. Surface charge is like the head of a fresh poured beer. Glass is full at first, but give it some time and it will settle down to its true level. Now I know if that battery is fully charged. 6+ plus hours sitting out of the boat, or about 3 10 second crank cycles if in the boat hooked up. Then check voltage.

IF the battery is good AND was fully charged, the ISO is not your issue in this no-crank scenario. Bad starter or bad cable.

[MexTex]

You were right on the money. The starting battery was the issue. I replaced the battery and she started right up. One thing that I did notice when I took a picture of the ISO, was that the far right cable (labeled B3) on my diagram above had a tag on the cable labeled primary isolator. This cable is going to my starting battery and not my deep cycle. Is it okay wired like this or should this wire go to the deep cycle battery?

[chpthril]

The diode ISO is indiscriminate, so it wont matter which outside cable goes to which battery. I would next make sure that each battery is getting a good charge level from the alt. when the engine is running.