Dash lights

tpenfield

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Jul 18, 2011
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18,202
Re: Dash lights

I would check your current engine for the audible warning system. I had a 1991 7.4L Mercruiser and it had a buzzer alarm for oil, temp, and outdrive fluid level.

An audible alarm would be a lot simpler to add than a warning light system, if you don't currently have one.
 

lynnboy021

Chief Petty Officer
Joined
Jan 27, 2008
Messages
553
Re: Dash lights

No I don't have anything on the motor.... I just don't wanna be having a good time and my engine is over heating and it will be to late..... It happend to me on my first boat, the motor got so hot that I was going to turn it off but with key off motor was still running and the paint on the valve covers was pealing off.... I am a person that I like things done right so I can be more boating less fixing....
 

wrench 3

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Aug 12, 2012
Messages
2,108
Re: Dash lights

No I don't have anything on the motor.... I just don't wanna be having a good time and my engine is over heating and it will be to late..... It happend to me on my first boat, the motor got so hot that I was going to turn it off but with key off motor was still running and the paint on the valve covers was pealing off.... I am a person that I like things done right so I can be more boating less fixing....

If your out there having fun you're much more likely to notice an audible alarm. I don't know what your instrument panel is like, but mine has a 4" overhang at the top and I still wouldn't stand a chance of seeing a light come on if the sun was out!
They're easy to install. As I said before, there is only one wire running forward, a jumper wire between the two sensors and an ignition feed at the instrument panel.
 

sam am I

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Jun 26, 2013
Messages
2,169
Re: Dash lights

I suppose Xbox trace repair puts you in the ball park somewhere.......

Ahhhhhh, but you do have "things", or going to have things on your motor eh?

You've been following along I assume?

1) You put a "switch" on for oil pressure? I gave you a link

2) You put a "switch" on for water temp? I gave you that link

3) Figured out you have the perfect alt to turn a light on when the alt. is dis-charging.

4) I'm giving you a circuit to turn a switch(relay) on when your fuel is low

Seems to me you have all the makings to not only now turn on individual lights for four distinct issues but........If you can turn a light on, couldn't, if you choose too, turn a horn on too? Hmmmmm, com'on now, think like an engineer.

Sooooo, after your lights are all tested and working like you want, And if you WANTED a horn to alert you of any or all of the four monitored systems failing/out of range, wouldn't you just need to "OR"(hint) each of those lights' signals? And then the output of this "OR'ing"(hint) thingie would just go turn on a Horn or buzzer or even call and alert the President to make Ice? Something to ponder I suppose.

OR Gate.jpg

Anyway........The Schematic

Low fuel Light.jpg

Referring to the plot below and schematic above ....


The voltage on the fuel gauges' "S" terminal (green trace...rough seas obviously) is the voltage representative of the gas [via a float and sender(potentiometer wired as rheostat)] in your tank and of course is displayed by the needle on your fuel gauge and varies from around 2.3 volts (full of gas) to 5.2 volts (empty of gas). **Standard sender 33-240Ω, AMC, Stewart Warner and most all marine apps**

You will need to adjust R1 to achieve the threshold voltage (Blue trace), such that when the green line goes above the blue line minus delay(see below) will set where the relay turns on(red trace), lighting up your light. When the green line goes below the now set blue line minus delay(see below) is where the relay turns off(red trace), turning off your light.

I have it here at 4.5 volts (maybe 1/8 of a tank) in the simulation below just for show and tell.

As seen in the plot....I put a "sloshing" delay to dampen things a tad, so you have about 15 sec's before the relay turns on when the gas goes below (voltage above) the threshold and about 10 sec's before it turns off when the gas goes above(voltage below) the threshold.

fuel 3 plots.jpg

Radio Shack part numbers to follow later.......I have a date with some Chicken parts and BBQ'er

Relay : Catalog #275-241 $4.49
M1 : Catalog #55052763 $0.78
U3 : Catalog #276-1778 $3.14
U1 : Catalog #55053130 $4.46
R1 : Catalog #271-343 $2.99
C1 : Catalog #55047742 $4.39
C2 : Catalog #272-1436 $1.99
C3 : Catalog #272-1028 $1.49
Rx's : Catalog #271-003 $10.99
Vector Brd : Catalog #: 276-148 $2.00

Total : $36.72 + Labor

271-003 is the family pack of misc. resistors which will include what you need, buying them in bulk should save you $10.00 or $15.00.

I still suggest you buy what the dude has already made up I suggested up in post #16.......will save you a major headache unless you've done this before............steep'ish learning curve here.

But, if you make it, plz post it here or to a new thread for the board members that may be interested.


GL and may the force be with you.
 
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lynnboy021

Chief Petty Officer
Joined
Jan 27, 2008
Messages
553
Re: Dash lights

Radio Shack part numbers to follow later.......I have a date with some Chicken parts and BBQ'er

lol

I already have the switches on order
 
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