Guages just won't work

[Alphasooner]

Hey guys, I am a newb on the forum here so I hope I am posting this question in the correct place. I have had a 1990 Nitro fish/ski for about 6 years now and it seems each year I have lost a different guage. Now I have no functioning guages. I thought that perhaps the guages were just going bad so I replaced one to check and it still didn't work. I hate to keep spending money without knowing what the problem is. Is there something that controls all of the guages on the engine or somewhere? It seems like it should be a simple fix. I would appreciate any help and guidance. Thank you.

 

[oops!]

Re: Guages just won't work

each gauge is controlled by a different "brain"

i.e...... oil pressure, oil sending unit.

but....lets get this moved to an area where the electric gurus can get at it.

 

[lrice01]

Re: Guages just won't work

Welcome to iboats!

It would probably help if you listed the specific gauges you are referring to.

Lee

 

[Silvertip]

Re: Guages just won't work

First, understand that there are only two gauges on the console that are engine specific for most older two-stroke motors. One is the tachometer and the other is the trim gauge if you have one. If your engine is newer and happens to be a four stroke, it may have temperature and oil pressure gauges so those senders could affect gauge operation. A water pressure gauge (again if you have one) is not an electrical gauge. Most older two strokes don't have temperature gauges but some of them have had them added aftermarket. So question #1 from me and others, is what engine do you have, what gauges do you have (all of them) and which work and which don't. Analog auges themselves rarely are bad and it is usually bad wiring or corroded connections that are at fault. If the gauges are digital then that's a whole 'nuther rats nest of issues. Here is a generic boat console wiring diagram that should help isolate the problem. Wire colors were chosen for clarity and contrast for web viewing and will very likely not match the wiring in your boat.

 

[Alphasooner]

Re: Guages just won't work

Thanks so much for the quick responses. First off, the engine is a 1991 Johnson 150 hp. The guages are analog. The trim, tachometer, and speedo are all non functioning. The only guage that works is the fuel. Last year I replaced the trim guage and it still didn't work. I thought I cleaned the connections well but perhaps not. The speedo is the type that works via a mechanism in back of boat and that has always been broke so I believe I know why that is non functional. To the eye everything appears to be in decent condition (i.e. rust or obvious splits). The fuse breaker area is a good candidate to be inspected after viewing your chart. Also, the guages have all failed at different times over several years. I really appreciate all of the input you guys are awesome. Jason

 

[Alphasooner]

Re: Guages just won't work

I hope that you guys are still out there. I cleaned and replaced all connections at the back of the boat where everything is tied into the power system I believe to no avail. Backtracked the trim and tachometer wiring to the motor and everything seems to be in great condition. I suspect that whatever ails me is on the engine somewhere, but I hope you guys can try to set me on the right path. Thank you. Jason

 

[Silvertip]

Re: Guages just won't work

Unless you are able to actually measure voltages you can look all day long and not determine where the problem is. Do you have a multi-tester (volt-ohm meter) and know how to use it? That's the only way we are going to be able to help is to have you take voltage and resistance measurements.

TRIM GAUGE: Did you check the trim sender on the engine. This is located on the transom bracket. Key on -- measure voltage on +12V and ground terminals of the gauge. If not there, you have a wiring issue to correct and the issue is NOT on the engine.

TACHOMETER: Needs +12V and ground. Measure at the gauge with key on. If not there, there is wiring issue and it's NOT at the engine.
Set meter to AC and start engine. Measure "S" (send) terminal to ground). Any reading above about 3V is ok. Lack of voltage on this line indicates the regulator is not working or there is a bad connection. Battery would also not be charging. Battery voltage should read above 13V at about 1500 RPM.

 

[Alphasooner]

Re: Guages just won't work

Silvertip you are indeed a Supreme Mariner. I have to be honest it's been awhile since somebody completely talked over my head. Alright I have an older Amprobe device. It has AC A 6, 15, 40, 100, and 300. AC V 150, 300, and 600. And then it also has a green X100 and X1. I am not sure if this is the same as multitester you referred to. If not, I would appreciate your advice on a quality tester.

Am I correct in assuming that the red lead goes to +12V and the black to ground? Do I just place the two probes on the wire leads behind guages? What will I want to look for around trim sender? Is there a test to be done with multitester there? I will do the same exact thing with tachometer sender as well I assume.

"Measure "S" (send) terminal to ground" you threw me here. Would you please elaborate more on what this is.

If I've exhausted your patience Silvertip I apologize. I appreciate all and any advice you may have. Thanks. Jason

 

[Silvertip]

Re: Guages just won't work

You have an AC (alternating current) tester. Everything you need to test on the boat is DC (direct current -- as in battery) so it's of little value. As a substitute you can buy a test light or better yet go to Radio Shack, Lowes, Home Depot and buy an inexpensive (about $10) multitester. It will measure DC volts, AC volts, resistance (ohms) and in some cases, very low current (amps).

When I said check the trim sender, I didn't specify any tests as it would require a tester. I merely wanted you simply look at it to see if its broken or a wire has become disconnected or broken. Those senders are located where the engine tilts and a little paddle type lever moves an arm inside the device that changes resistance. That's what the trim gauge is responding to.

There is no sender for the tach. The "S" terminal is on the back of the tach and gets a signal from the rectifier in the engine. A malfunctioning tach is one indication that the charging system may not be working. So the first test to make sure the voltmeter (if you have one) on your console reads 13 volts or higher at about 1500 rpm. If you don't have a voltmeter on the console you again need the tester to measure the voltage at the battery at 1500 rpm.

And Yes -- the red lead is always the "hot" lead so it goes on the circuit or terminal you are testing. The black lead is ground and goes to the ground terminal.

 

[Alphasooner]

Re: Guages just won't work

Silvertip,

I went and bought multitester and thanks for advice on that. I tested for voltage on the +12V and ground terminals on the trim, tach, and fuel. All tested positive for voltage. I am going out later and will test the "S" and Ground terminals of tachometer at idle and 1500 rpm(no voltmeter). I will provide feedback after return. Also, the wiring to trim sender was in fine condition. Once again, thank you for your time and knowledge. Jason

 

[Alphasooner]

Re: Guages just won't work

Silvertip,

This is what I found out today in addition to last post. Tested the "S" and ground on the tachometer. The measurement that seemed most accurate of the 500, 250, 50, and 10 ACV choices was 50. It showed a reading of 1-3 volts while idling and at approximately 1500 rpm. It never fluctuated when increasing rpm's. If I read correctly what you posted earlier that is not right. I would appreciate any further instructions you might have. Thank you. Jason