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View Full Version : Digital multi function gauges off ebay, how are they?



vpt
07-17-2019, 08:39 AM
I am looking at this gauge: https://www.ebay.com/itm/Boat-Car-GPS-Speedometer-Tachometer-Oil-Pressure-Fuel-Level-Gauge-Voltmeter/132901700889?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2060353.m1438.l2649


But I have all the questions and hope someone has experience with them or know someone who does.

My first question is the back light. They mention 'default' is a cycle threw the 6 (or however many) colors the gauge offers. I am curious if once you manually select a color will it stay that color every time you use it or will it go back to default every time?

Second question is wiring power to the unit. They mention "gauge can be wired directly to power". Does that mean it has an 'auto off' if not in use for awhile?

On the wiring sticker it mentions "gray-multi function buttons" I am assuming this wire can be wired to an external button to do the same functions as the button(s) on the back of the gauge? If this is true it would make me worry a bit less about the backlight default problem.

It is an interesting gauge and looks like it could be handy for all sorts of applications so long as it works. I am looking to get it for a pontoon boat I am putting together. I really only need the tack and fuel gauge but don't have room left for multiple gauges.

I sent all the same questions to the seller but am expecting a very generic reply.

Sparky_NY
07-17-2019, 08:50 AM
NO mention of signal levels or formats for the various inputs. Suggests that GPS is used for speed.

Ringo
07-17-2019, 08:55 AM
My questions are to the input signals.
Are they for the old style analog gages, or, newer digital sending units?
Even on the old analog gages the sending units had to be matched to your analog gage, the output signal range.
On newer digital gages, the NMEA 2000 protocol is mostly standardized, but the listing doesn't specify.
What engine you got, digital output or analog?

Ringo
07-17-2019, 09:05 AM
that is interesting enough I might want one too,
I found the owners manual on a different website, it is analog,
https://www.aliexpress.com/item/32921183009.html

vpt
07-17-2019, 10:01 AM
My questions are to the input signals.
Are they for the old style analog gages, or, newer digital sending units?
Even on the old analog gages the sending units had to be matched to your analog gage, the output signal range.
On newer digital gages, the NMEA 2000 protocol is mostly standardized, but the listing doesn't specify.
What engine you got, digital output or analog?


The engine is a 2005 3 cylinder 50hp Merc. Honestly not sure what the factory tach output is on this motor. From what I understand a "tach" signal can be pulled from pretty much anywhere on a 2 cycle outboard whether it be a coil, cdi, or charging circuit. Basically anything with a pulse from the motors revolutions. I know what an analog signal is, but don't fully understand what a "digital" tach signal would be? Is there a difference?

vpt
07-17-2019, 10:04 AM
NO mention of signal levels or formats for the various inputs. Suggests that GPS is used for speed.

Yes the speed is generated from the gps signal it seems. Even if within 5mph +/- that seems like a very simple and neat way to display speed especially on a boat. I like that.

As for the other inputs I am not 100% sure yet either. I assume the "volts" is a no brainer 12+input. Besides the tach the only other one I am concerned with is the fuel level input. The tank I have has the typical analog ground signal, I didn't give it much thought but hope that would work with this gauge.

Mike Amick
07-17-2019, 11:46 AM
That is really cool. Wish I had something to put it on.

Glug
07-17-2019, 05:26 PM
I bought an import hour meter with rpm on ebay. It was supposed to be completely waterproof. In fact, the battery was sealed inside. It worked fine on the tractor during winter, but as soon it got wet it quit working and started fogging. By then the 30 day 'warranty' was over and the seller would do nothing.

That is a completely different device than what you are looking at. But I notice the mutli gauge only has a 30 day warranty.

true temper
07-17-2019, 06:39 PM
Cool idea on gauge, but I don’t like it because you really have to pay attention to read oil pressure and temperature. I like separate gauges for them, you can glance at them and tell if they are reading right.

vpt
07-17-2019, 08:14 PM
Cool idea on gauge, but I don’t like it because you really have to pay attention to read oil pressure and temperature. I like separate gauges for them, you can glance at them and tell if they are reading right.


Maybe it was a different gauge I was looking at but I thought it said it has a programmable alarm you can set for low/high readings.

boats
07-17-2019, 09:34 PM
I don’t know about the other functions but use top quality GPS on a couple of workboats. Speed over the bottom reading is extremely accurate. So accurate I can figure current speeds adverse or favorable by comparing GPS over the bottom reading to known through the water speed for a given RPM. Long runs known distance time checked with a watch published current data factored confirms the units accuracy. Offshore standard practice is use the GPS as primary to track speed verifying when known marks are available.

However GPS accuracy is dependent on the signal received and more important how many satellites the unit is tracking. Most good units have a function that shows what satellites they are tracking. 3 sats minimum. Accuracy goes up as it locks onto more. Hundred dollar multi function unit built into the dash have to wonder how well it tracks.

Having said that use Waze on your Iphone in the car, gives you speed that can be verified with a stopwatch and interstate mike markers. It’s spot on and fits in your pocket.

Fuel consumption any commercial vessel sounds tanks with a tape or if small a graduated stick, nobody relies on a dash gauge. About the only one you will see is a glass sight gage side of the day tank in the engine room. Too many ways remote gage float actuated can read inconsistent

I recommend making up and calibrating a fuel dipstick even for small outboards . My little Aluminum fishing boat 15 HP 4 stroke Yamaha with 2 x 3 gallon tanks have a stick that tells exactly what’s in the tank.

Boats

BigBoy1
07-18-2019, 01:41 AM
I'd make sure the power to the gauge runs through the ignition switch. You really don't want to have it on all the time, draining the battery.

vpt
07-18-2019, 10:01 AM
I got some stuff from the seller.

https://i.imgur.com/g8LgO7g.jpg

https://i.imgur.com/ALswtpO.jpg

vpt
07-18-2019, 10:15 AM
I'd make sure the power to the gauge runs through the ignition switch. You really don't want to have it on all the time, draining the battery.

From what I assumed before by the generic ebay add was that 12+ was hooked directly up to the gauge (to retain memory) and the gauge would auto shut off after so much time of no action. Seeing the "instructions" now I see it does in fact show running the power threw the ignition.

I think I'll order one, looks like its got all the right stuff for me.