clinton

[clinton]

I'm pretty old to this world but new to this forum. My 1999 SunSetter has issues with cluster gauge readings. Oil pressure is either erratic or pegged at 80#. Fuel gauge seldom works. Engine temperature reads ok at first then is erratic to high 240+. I've changed the oil sending unit. Replaced the thermostat, water pump, water pick up empeller. Replaced fuel tank sending unit. Quite sure there is no problem with the engine because I ignored the gauges and ran it all summer. Runs perfectly. My question is there any way to test to see if the cluster gauges need replacing or if the MC board is the problem? Or is it both? And where is the MC board? Frustrated but not giving up.

  

[Sixball]

I would start with the grounds for the gauges. ( under the dash)

[drh]

I agree with tightening the connections to the grounding bar under the dash as a first step. There will be a bunch of black wires running to a bar and for my 99 it was under the dash to the right of the steering wheel. I had a grounding issue that showed up as an increasing reading on a gauge every time I turned on an accessory. Like when I turned on the blower the temp gauge would go up a bit, turn on the stereo it would go up a bit more. All of my connections were tight on the grounding bus bar so I solved this by running a thick gauge wire directly from the battery negative terminal to a stud on the bar.

The gauge computer is mounted under the dash as well. It's a small black box with a one large and one small connector running to it. Do your gauges buzz and reset when you key on or do you have any that hang up at min or full scale?

 

[Bozboat]

While you are under the dash, consider cutting the pitot tubes.  They will eventually deliver water into the Medallion Dash Computer and wreck it.  One sign is water dripping on your feet while driving.  You could wait like I did and then replace the MDC after it gets soaked.  Nautilogic makes a plug in GPS conversion that is well worth the money.

Edited October 13, 2017 by Bozboat

[clinton]

On 10/13/2017 at 10:31 AM, drh said:

I agree with tightening the connections to the grounding bar under the dash as a first step. There will be a bunch of black wires running to a bar and for my 99 it was under the dash to the right of the steering wheel. I had a grounding issue that showed up as an increasing reading on a gauge every time I turned on an accessory. Like when I turned on the blower the temp gauge would go up a bit, turn on the stereo it would go up a bit more. All of my connections were tight on the grounding bus bar so I solved this by running a thick gauge wire directly from the battery negative terminal to a stud on the bar.

The gauge computer is mounted under the dash as well. It's a small black box with a one large and one small connector running to it. Do your gauges buzz and reset when you key on or do you have any that hang up at min or full scale?

 

Gauges buzz and reset when I key on. No gauge hangs up. Ground connections are all tight and I ran a temporary ground from the battery negative post (battery is behind observer seat) to the ground bar. Still erratic oil pressure reading and no fuel reading. Temp gauge seems to be ok at idle and low throttle speed but goes high after running @ 34mph and then goes up and down. Amp gauge works good.

I winterized the boat today and the temp gauge stayed normal during the run to warm up engine oil so it would drain out good. Oil gauge was pegged @ 80#. Guess I'll take this back up in the spring.

Thanks for your comments.

[clinton]

On 10/13/2017 at 3:47 PM, Bozboat said:

While you are under the dash, consider cutting the pitot tubes.  They will eventually deliver water into the Medallion Dash Computer and wreck it.  One sign is water dripping on your feet while driving.  You could wait like I did and then replace the MDC after it gets soaked.  Nautilogic makes a plug in GPS conversion that is well worth the money.

I'll definately cut those pitot tubes. No water dripping yet. And I plan on getting a GPS speed control before next spring any way.

Thanks.

[Bozboat]

9 hours ago, clinton said:

I'll definately cut those pitot tubes. No water dripping yet. And I plan on getting a GPS speed control before next spring any way.

Thanks.

GPS Speed control would be my first choice.  I did I see on here the other day where a person had installed one of these GPS Speedos  I don't have any experience with them but the price is right and the install looks simple.

Edited October 17, 2017 by Bozboat

[Steve B.]

Clean the umbelical connection.

Steve B.