Cockpit Volt Gauges Reversed

[Deep in Depth]

I know this sounds simple to fix but I want to do it right.

2000 Searay 410 Sundancer
3116T Cats

I am the second owner and have had this boat for 9 years.

I was troubleshooting housebank poor performance or I may not have noticed this.

When I start my left engine, the left batteries read on the right gauge and when I start the right engine, the right batteries indicate on the left gauge.

I have checked and the right batteries are supplying DC to the right engine and the left batteries are supplying DC to the left engine. So this is an indication issue not an engine battery wiring issue.
I have also checked the volt gauge on the DC power panel when starting the engine and it is also correct.
I could rewire the dash and have proper indication of DC volts but now I have introduced another undocumented change. I would like to do this right!

My question is: Where does the instrument panel (volt gauge) take its power from? I think someone may have these wires reversed.

 

[Sublimetime]

You say its when you start the motors.... so I guess it is the alternator charge that is being indicated. I would follow the wires from the alternators which probably go to battery combiners/isolators and got crossed there somehow.

 

[Deep in Depth]

I may need to clarify...the volt gauge are as if they were on the wrong side. The wiring or indication to the DC panel below deck is reading correctly...start the left, the draw is off the left bank...but if you put both engines to the first click (ACC), the right volt gauge shows the draw when starting the left engine. The wiring behind the gauge looks factory and unmodified. I believe there is a connection somewhere either to the start switch or ??? that is crossed.

 

[Deep in Depth]

Sublimetime...thank you for your comments.

 

[dlvwill]

Swap the positive wire between the two gauges. Usually purple or may be red.

 

[Deep in Depth]

Swap the positive wire between the two gauges. Usually purple or may be red.

Good morning Divwill. Yes that may be what I do until I find where in the line, the connections are swapped. I will need to make up two extension wires as the factory ones are cut to length.

These gauges must pickup the volt reading somewhere in the system. I thought it was at the main terminal where 12v comes through the bulkhead to the DC distribution panel below deck but I cannot locate these specific wires at the panel. I am hoping someone was worked in this area before.

I have confirmed the boat is wired correctly to the DC distribution panel beyond that appears to be the issue.

I see lots of thunder storms coming your way. Take care.

 

[JVM225]

Sounds like someone had that panel out for some reason and may have plugged the wrong wires in to the wrong gauges when they re-assembled.

 

[ZZ13]

Good morning Divwill. Yes that may be what I do until I find where in the line, the connections are swapped. I will need to make up two extension wires as the factory ones are cut to length.

These gauges must pickup the volt reading somewhere in the system. I thought it was at the main terminal where 12v comes through the bulkhead to the DC distribution panel below deck but I cannot locate these specific wires at the panel. I am hoping someone was worked in this area before.

I have confirmed the boat is wired correctly to the DC distribution panel beyond that appears to be the issue.

I see lots of thunder storms coming your way. Take care.

Power to all your gauges come from the corresponding start switch. That's why none of the gauges sense a reading until you depress that switch.

 

[Deep in Depth]

Thanks for the reply ZZ13.

I have power at all gauges and if I swap any power connection on the start switch left to right. The fuel solenoids are not powered unless I have both ign switches on at the same time. So I put these back to the original location.

I started with power to all gauges but when I cranked the engines, the draw was indicating on the opposite volt gauge as well as the charging status of the batteries. I ran a jumper basically crossing the violet wires to the opposite gauge. Now when I turn the left start switch on, I see voltage on the right side voltage gauge. The results are the same for the right side with voltage reading on the left volt gauge. Now, when I crank either engine with both ign switches in the on position, the voltage draw for the starter is displayed on the correct side along with the charging from the alternators. This is the best of the two evils for now but its still not correct. I believe that in that big bundle of wires behind the dash, in one or more of the plugs, there are two wires crossed, maybe from the factory. Maybe its not just my boat that is improperly wired.

I am going away for 2 weeks and will continue troubleshooting then.

 

[Deep in Depth]

Update: On the back of the start switch, there are 4 spade connectors. The top 2 are for power in, one is 12v DC and the other is from the crossover switch between the 2 start switches and also supplies 12v DC. They are also linked together within the switch. The 12V source is from the respective solenoid and respective batteries.
While starting the starboard engine, the draw is confirmed from the starboard designated batteries,
The bottom 2 spade connectors on the switch are outputs for various functions. One is for the starter power and the second is for fuel solenoid. If I read this correctly, Searay also takes power off the fuel solenoid output to supply power various gauges. I have confirmed through the Searay wiring drawings the boat is wired IAW their drawings.
Here is what I have found:

1st the problem in more detail

• When I test these wires in the factory configuration, I turn the PORT engine to the ON position, I read battery volts on the VOLT gauge and the same for the starboard side. When I start either engine by itself, there is no draw displayed on the gauge from the starter or charge being displayed on the running engine volt gauge.
• If I put both engine switches to ON and try to start either engine, I see the starter draw on the opposite engine volt gauge and once the engine is running, the charging is displayed on the opposite side. This is the same for both engines.
• Seems simple, the wires are swapped...not so simple

I reversed the purple 12v source wire going to each VOLT gauge (port wire feed starboard gauge):

• When I turned the PORT engine to ON, nothing was displayed on the volt gauge. The same happened when I did this for the Starboard engine. (only one switch on at a time)
• When I turned both engines to the on position, I read VOLTS on both VOLT gauges but this was reading on opposite sides, PORT gauge reading STARBOARD battery volts...etc. The difference now is when I start the engine(s), I read the draw and charge for the correct side.
• Now, I see Battery VOLT indication is reversed but the draw/charging is indicated correctly..mmm

What I see behind the panel is the original Searay connectors and install. It does not seem to be disturbed and there are no splices in the wiring. I have replaced the panel itself but took pictures of the wiring and made sure it was the same as when removed.
There is no doubt there are at least 2 wires crossed but I have run out of specific tests without disturbing the original install...that may be next. It is likely there are 2 pins reversed in the large bundle of wires and plugs under the dash. I will leave the boat in the second configuration for now but the testing goes on.

I have the wiring diagrams should anyone like a copy to review.

Thanks

 

[Deep in Depth]

Finally I found the issue with the wiring. The wirebundle has the two power supplies going to the start switches and these were reversed. These wires are in a Main wire bundle and exit the wire bundle to mate with the corresponding switch. I needed to remove the wires from the bundle and reroute to the other start switch. These appeared to be the factory setup as far as I could see.

Thanks for your input and I may not be alone with this issue.