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Tan, MerCruiser Certified Technician
Category: Boat
Satisfied Customers: 10744
Experience:  40 yrs. experience with complete engine repairs both inboard/outboard and MerCruiser Certified Technician.
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I have a 1989 sea ray 280 sun dancer that seems to have a

Customer Question

I have a 1989 sea ray 280 sun dancer that seems to have a ground problem with dc grounding, IE: lights dim when you turn on more lights or when when domestic water pump runs. I am looking for a wiring schematic. I also wonder if batteries are hooked up correctly. Thanks, ***** *****
JA: Sometimes boat issues seem like they'll be really complicated, but end up being easy to fix. The Marine Mechanic I'm going to connect you with knows all the tricks and shortcuts. Is there anything else important you think the Marine Mechanic should know?
Customer: no
Submitted: 9 days ago.
Category: Boat
Expert:  Tan replied 9 days ago.

Hello, I'm Tan. Welcome to JustAnswer. I'm reviewing your question and will reply momentarily.

Expert:  Tan replied 9 days ago.

Have you had the batteries tested and or out?

Customer: replied 9 days ago.
New last summer and load tested fine last month
Expert:  Tan replied 9 days ago.

Ok we need to start with a voltage of the batteries at the batteries. Do you have good voltage?

Is the converter/battery charger on?

Customer: replied 9 days ago.
Expert:  Tan replied 9 days ago.

What is your voltage reading when you start turning lights on at the battery?

Have you changed any wiring since the last time the lights worked correctly?

Customer: replied 9 days ago.
Voltage always is around 12 which is a little low, 13.5 is supposed to be normal and the only thing that changed was re install batteries this spring
Customer: replied 9 days ago.
I have built drag cars and wired everyone myself, I just dont have a schematic to help me find problem
Expert:  Tan replied 9 days ago.

Ok go to the batteries and check all the grounds and battery charger wires are connected. The battery charger should have the battery voltage up higher than 12 volts at least 13+ volts. So either their is a wire off at the batts or the charger isn't working. Do you hear the charger?

Customer: replied 9 days ago.
The charger seems to work ok but charger only has three charge wires and I have four batteries. I can't tell which positive lead goes with which ground
Expert:  Tan replied 9 days ago.

The ground is common between the all batteries. Do you have a jumper wire between all the batteries negative/ground side of batts?

Customer: replied 9 days ago.
The previous owner had installed all new gauges, I don't know how that could effect anything. Even at 12 volts one incandescent bulb should not dim when another one is turned on. This boat also has a generator
Customer: replied 9 days ago.
Are you still there
Expert:  Tan replied 9 days ago.

Ok we are back to the battery charger. If the charger isn't charging the batteries your light will dim when you turn more lights on. Lights draw more amperage than you think. We need to verify that the charger is actually charging the batteries.

The gauges are only energized when key is in on/run position.

Customer: replied 9 days ago.
Ok I will test all battery charger leads for voltage ang amps tomorrow so I can give you a complete answer. Will you be available tomorrow? I am also sure that this is not a major problem but it makes me crazy!!! When I start engines voltage does go up to 13 plus volts but sometimes it will still read low on voltage. Any ideas?
Expert:  Tan replied 9 days ago.

I will be available tomorrow.

The volt meters in SeaRays are notoriously inaccurate.

Most time loose or corroded connections are the problem. So double check that all the wires are clean and tight. Be sure that none of the grounds have been dropped off the batts and laying next to the battery. Then check for battery charge at each battery with charger on. You must have around 13 + volts to indicate the charger is working.

Customer: replied 9 days ago.
Expert:  Tan replied 9 days ago.

Your welcome..........Talk tomorrow.

I looked for a wiring diagram on the Searay site none of the owners or parts manuals had anything.

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