87 300 Sundancer Inst. Lights Ground

JVM225

Well-Known Member
Apr 8, 2008
6,560
New York
Boat Info
2002 410 Sundancer, Monaco Edition.
Engines
3126 Cats.
I'm posting this in the hope that someone can steer me in the right direction.
The Instrument/Dash lights on my 87 300 Sundancer work intermittently. It looks like a classic loose or dirty ground problem. It must be a common ground for the lights because they all go out at once and come back on together. When the lights are out, the gauges still work.
I was wondering if anyone knows where the common ground for the instrument lights is located.
Thanks!
 
I'll see if I can help you here, I recently took all my gauges out to replace the dash and I hope this info is accurate, it is for my 95. If your gauges are working and the gauge lights are intermittent here are a few starting points:

1) Each gauge has it's own ground so it's not the ground if the gauge itself is functioning
2) Each gauge will have a Blue wire connected to the power for the bulb
3) The above Blue power leads are daisy chained together, if the first connection is loose all will go out.
4) Same goes for the bulbs, since they are all powered off the same Blue lead if the first one goes out the rest down line will too. (I found this out when forgetting to replace the first bulb and wondering why the hell the dash lights didn't work)
5) On your lighting switch, the above blue lead originates, loose=no lights
6) There should also be a dimmer where the leads could be loose/corroded or bad dimmer.

I would check the switch, then the dimmer then each bulb in order. Hopefully it is easy to spot... FYI you can buy replacement bulbs at any autoparts store and they are type 194 bulbs. The little bayonet style bases can and do work loose.

Dan
 
Thanks! The bulbs all seemed tight when I checked. I'll look for the dimmer, but I'm pretty sure my boat doesn't have one.
Maybe I'll just pick up a couple of new bulbs and replace them along the line to see if one is out.
The problem is intermittent which led me to believe that it was a loose, dirty, or corroded common ground, but your suggestions also make sense.
 
Last edited:
I'll see if I can help you here, I recently took all my gauges out to replace the dash and I hope this info is accurate, it is for my 95. If your gauges are working and the gauge lights are intermittent here are a few starting points:

1) Each gauge has it's own ground so it's not the ground if the gauge itself is functioning
2) Each gauge will have a Blue wire connected to the power for the bulb
3) The above Blue power leads are daisy chained together, if the first connection is loose all will go out.
4) Same goes for the bulbs, since they are all powered off the same Blue lead if the first one goes out the rest down line will too. (I found this out when forgetting to replace the first bulb and wondering why the hell the dash lights didn't work)
5) On your lighting switch, the above blue lead originates, loose=no lights
6) There should also be a dimmer where the leads could be loose/corroded or bad dimmer.

I would check the switch, then the dimmer then each bulb in order. Hopefully it is easy to spot... FYI you can buy replacement bulbs at any autoparts store and they are type 194 bulbs. The little bayonet style bases can and do work loose.

Dan

My boat doesn't have a dimmer, but it looks like not much else changed behind the dash between 87 and 95.
The lights on my gauges are all hooked up in series from starboard to port with blue wire, and the last length of blue wire runs from the last gauge to a blade connecter on the back of the Nav Lights/Anchor Light toggle switch on the dash. It is one of three blades that is connected to the rear of that switch.
Mine had worked it's way loose and turned a little green over the winter. I cleaned it with CDC, re-connected it securely, and all is working fine now.
Thanks for the tip. It helped alot.
 
Glad I could point you in the right direction, have a great Memorial Weekend, Dan
 

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