Electrical question

[waternutt]

I am not the smartest when it comes to wiring diagrams and electrical systems, so I am hoping someone might be able to assist. This also ties into another question here in the Chaparral forums inquiring about start and house batteries. I am just trying to get a better understanding of the boat's electrical system.

I recently replaced the batteries in my 2016 243VR. It has dual temp/voltage gauges on the console. Before I pulled the old batteries, I was getting a "Starboard Low Voltage" warning on the display. However, it was the left gauge (port) that was showing low. I figured perhaps the wires got crossed to the gauges on installation and I just never noticed.

Moving on to new battery installation...I initially installed the starboard battery. With just the starboard battery connected, it appeared to have no electrical power to the boat (no blower, display, or gauges) with the battery switch both in ON and COMBINE. So I then disconnected the starboard, connected the port battery and placed the battery switch in ON. I now had some power (blower, display) and the right (starboard) gauge was the one to come alive. I attempted to start the engines but got nothing.

Following my earlier suspicion of crossed wiring to the gauges, I swapped the wiring to the two gauges and tried again. Blower, display, and the same starboard gauge came alive. Now this is where I got confused, so I just swapped the wiring to the gauges back, re-installed the starboard battery, checked that engines would start, and plugged in the smart charger to top off the batteries.

I still need to attempt digging into the wiring diagrams, but a few question come to mind.
1. Why did the same temp/voltage gauge come alive despite swapping the connections?
2. Why was there no power to the boat with just the starboard battery connected?
3. Why would neither engine start with just the port battery connected?
4. Do these boats have a dedicated start and house battery?

I understand this is a lot to unfold, but I would appreciate any insight anyone may have. Thanks.

 

[Julio Dimperio]

With just the STBD battery connected, there is no power to the helm, and the boat won't start. Both batteries are for starting. The battery switch simultaneously switches the two batteries off, on, or combines them if turned all the way. Attached is a sketch of my boat battery switch diagram. Regardless of battery switch position (including off), the STBD battery powers the STBD engine ECM and auto bilge, and the port battery powers the port ECM and eReverse module (via a wire connected directly to the positive terminal). Switched to on, the port battery also powers the helm, the STBD battery also powers the ballast system, and both batteries are available to start its corresponding engine.

Your symptoms lead me to tell you to check the battery switch. Feel the resistance to turning it, and the detents should feel strong. If it is too easy to turn, it is probably failing and will cause voltage issues that may ruin other components. Replace it. This happened to me. I found a redesigned replacement on Amazon. There are other posts on this forum about how the Blue Sea battery switch used on these boats were defective, and one post shows a customer service number to call for a free replacement switch. Search for Blue Sea "m" series switch failure. Let me know what you find.

 

[waternutt]

Thanks for the response. So no dedicated start and house batteries and each battery powers different things. Even though each battery starts its corresponding engine, I assume both batteries need to be connected because neither engine would even turn over with a single battery connected.

I think my battery switch is fine. My batteries were old and probably due for replacement. Now to track down the gauge issue.

 

[Julio Dimperio]

waternut, if the battery switch is original, I would suspect it. While I was chasing voltage issues on my boat and checking the tightness of electrical connections to the switch, the switch fell apart in my hands. It looked fine but it was not. I was chasing voltage ghosts until that point.