Gauge Identification / Testing / Replacement

[dgyank70]

Hello all.
Mercruiser v6 4.3l with TKS
Serial #: 1A335597
August 2008 4.3 TKS
Family 8M9XM 04.32VC

I have a Nauticstar deckboat with the following gauges / multi gauge clusters (see attached).
None has a vendor mark that I've been able to find.
The multi functions have a plug style connector.
I was advised by the dealer they suspected they were Faria gauges, but I've sent to Faria and they said they weren't theirs.
Of the gauges, only the voltmeter and RPM are working.
So oil, temp, fuel, speedometer, and now trim as well are not working.
From the plug connector, you can see I don't have the access to the terminals on the back of the gauge to test it directly, as I've read about.
But I was told it's easy to find the sensors / sending units for these (even the oil, which I find hard to believe as it's very difficult to get to the oil filter, which it's near, I think), and test the gauges from that end.

I'm not very handy at this, but if you see my other post (having a buzzer sound / engine shutoff), you'll see why it'll be nice for me to at least have gauges telling me something (aside from during normal operation).

So I'm looking for advice / clarity on

1. testing the sending units (where do I find them on my engine?)
2. testing the gauges (especially the multi-gauge clusters- I've read how I can test a single gauge)
3. Potentially replacing the gauges (if bad);
   1. where the heck did they come from?
   2. Can I even find gauges that would 'match' the dash (i.e., the cutouts in that curved plastic stuff)?
   3. Can I find the exact replacement gauges?
   4. Would I be smarter to try to replace these multi gauges with individual ones?
4. I believe I know I need to match the sending units / sensors with the gauge, or at least ensure they're properly calibrated.

Thanks for any insight / suggestions.

 

[alldodge]

Contact Nauticstar manufacture directly. Most companies can find what was used by the hull number
https://nauticstarboats.com/


Otherwise look at places like VDO, Autometer and Faira for gauges that will work. Note the diameter size of the gauges then maybe find a quad gauge for oil pressure, water temp, gas, volts. Then find a MPH and Tach in another. Trim is easy enough

 

[dubs283]

My guess would be the lowest quality vdo gauges

You'll be better off replacing them. There is little chance any company can repair them

 

[dgyank70]

Thank you guys both. I think the manufacturer told me to talk to the dealer last time I checked... But I will doublecheck.
I definitely am not interested in repairing them...
Here are the sender / sensors I'm going to replace on the back end for starters:
(These part numbers are coming from the mercury parts catalog here,

Mercury Marine - A Worldwide Leader in Marine Propulsion | Mercury Marine

Manufacturers of outboard motors and MerCruiser inboard engines, with over 4000 dealers in the United States.

www.mercurymarine.com

based on my engine serial #).
So- I guess with the odd plug connection on the backend of the gauge, I would simply undo those wires and reroute them to the new gauges?
Do I have to worry about the sender 'matching' the gauge?
I know there's stuff about calibration, not clear how to reconcile that...

Thank you guys!

 

[dgyank70]

Thank you guys both. I think the manufacturer told me to talk to the dealer last time I checked... But I will doublecheck.
I definitely am not interested in repairing them...
Here are the sender / sensors I'm going to replace on the back end for starters:
(These part numbers are coming from the mercury parts catalog here,

Mercury Marine - A Worldwide Leader in Marine Propulsion | Mercury Marine

Manufacturers of outboard motors and MerCruiser inboard engines, with over 4000 dealers in the United States.

www.mercurymarine.com

based on my engine serial #).
So- I guess with the odd plug connection on the backend of the gauge, I would simply undo those wires and reroute them to the new gauges?
Do I have to worry about the sender 'matching' the gauge?
I know there's stuff about calibration, not clear how to reconcile that...

Thank you guys!

View attachment 381926View attachment 381927View attachment 381928

That's temp sender / sensor plus oil sender, I believe...

 

[alldodge]

805218T is the Temp switch and not for a gauge
806490T is for Water Temp gauge
8M0068764 is for oil pressure gauge

 

[dgyank70]

805218T is the Temp switch and not for a gauge
806490T is for Water Temp gauge
8M0068764 is for oil pressure gauge

When you say 'for a gauge' I think you mean a 'sender' that goes to a gauge, am I correct? I wasn't sure what the difference between the temp 'switch' and 'gauge' was...
Is 806490T correct for 'engine temp' sending then (actually measuring the cooling water I guess)?

And if I'm looking at Faria gauges like here at

Faria Beede Instruments® - Chesapeake Series Black Dial/Polished Stainless Steel Bezel 3.37" In-Dash Mount Multifunction Gauge

Chesapeake Series Black Dial/Polished Stainless Steel Bezel 3.37" In-Dash Mount Multifunction Gauge by Faria Beede Instruments®. Measurement Limit: Fuel Level, Oil 80 PSI, Water Temperature 100°-250°F, Voltmeter 10-18 V DC. Measurement Limit: Fuel Level, Oil 80 PSI, Water Temperature 100°-250°F...

www.boatid.com

Do I have to get Faria senders to go with them?
Or can I order the Mercruiser senders above?

Alldodge, I really appreciate your time and efforts to help me.. Thank you very much...

 

[alldodge]

When you say 'for a gauge' I think you mean a 'sender' that goes to a gauge, am I correct?

Correct

Is 806490T correct for 'engine temp' sending then (actually measuring the cooling water I guess)?

Correct

Do I have to get Faria senders to go with them?
Or can I order the Mercruiser senders above?

This is the unknown
I have not seen where "these gauges" use the North American standard but do "think" they do. The standard is 30 ohms to 240 [edit mistake in range]

 

[dubs283]

Standard is 30-240 ohm for boat gauges

The circuitry and gauge can be tested by grounding/applying 12 (+) volts to the sender wire end at the sender (disconnected). With key on engine not running the gauge should spike full max with ground applied and full min with 12 (+) volts applied

If this test fails on any oil pressure, temperature, trim, or fuel level gauge then the gauge or circuitry has failed

Tachometer, volt and speedometer gauges are not to be tested via this method

 

[dgyank70]

Standard is 30-240 ohm for boat gauges

The circuitry and gauge can be tested by grounding/applying 12 (+) volts to the sender wire end at the sender (disconnected). With key on engine not running the gauge should spike full max with ground applied and full min with 12 (+) volts applied

If this test fails on any oil pressure, temperature, trim, or fuel level gauge then the gauge or circuitry has failed

Tachometer, volt and speedometer gauges are not to be tested via this method

Thanks!!!

 

[dgyank70]

Standard is 30-240 ohm for boat gauges

The circuitry and gauge can be tested by grounding/applying 12 (+) volts to the sender wire end at the sender (disconnected). With key on engine not running the gauge should spike full max with ground applied and full min with 12 (+) volts applied

If this test fails on any oil pressure, temperature, trim, or fuel level gauge then the gauge or circuitry has failed

Tachometer, volt and speedometer gauges are not to be tested via this method

Thanks

Correct

Correct

This is the unknown
I have not seen where "these gauges" use the North American standard but do "think" they do. The standard is 30 ohms to 240 [edit mistake in range]

Thanks!!!

 

[nola mike]

Also, as far as testing the gauges, the wiring to the plug looks standard: blue-light, black-ground, purple -12v, last wire -sender.