Temp & Trim Gauges Not Working

[jamez]

I just bought a 1974 Glassmaster with an OMC 140HP I/O motor.
This is my first boat, and I am NOT mechanically inclined toward vehicles or boats. So please bear with my ignorance.

The temp gauge isn't working, and the trim doesn't work. Also, the tach is reading between 3000-34000 RPMs at wide open throttle.

Here are my questions:
1.) What is involved in diagnosing what is wrong?
2.) How much am I looking at to get this fixed?

 

[a70eliminator]

Re: Temp & Trim Gauges Not Working

1) electrical troubleshooting,trim sender, gauges & rewire
2) probably about 3 bucks

 

[wire2]

Re: Temp & Trim Gauges Not Working

The temp gauge isn't working, and the trim doesn't work. Also, the tach is reading between 3000-34000 RPMs at wide open throttle.


Here are my questions:
1.) What is involved in diagnosing what is wrong?
2.) How much am I looking at to get this fixed?

Are you comfortable with a voltmeter, or a test light? The temp gauge should have a +12v, ground, sender and light terminals. +12 and gnd are self explanatory, sender should have partial voltage on it, depending on engine temperature.

"Trim not working" Gauge only, or trim pump isn't working either?

Does the tach have a switch on the back to choose options?

 

[jamez]

Re: Temp & Trim Gauges Not Working

Are you comfortable with a voltmeter, or a test light? The temp gauge should have a +12v, ground, sender and light terminals. +12 and gnd are self explanatory, sender should have partial voltage on it, depending on engine temperature.

"Trim not working" Gauge only, or trim pump isn't working either?

Does the tach have a switch on the back to choose options?

I have a voltmeter, but I'm really not sure how to use it. My wife's grandfather gave it to me, so I'll ask him.

The Trim gauge isn't work and neither is the trim pump. I'll assume that the trim pump is what the previous owner meant when he said the trim doesn't work.

I don't know about the tach having a switch, but I'll look into this too.

 

[BAYLINER185]

Re: Temp & Trim Gauges Not Working

If your really not sure whats going on or how to check you may just want to bring it to a marine shop. It doesnt sound like that problem would be an expensive fix and that way you know its done right and the boat is safe.

 

[wire2]

Re: Temp & Trim Gauges Not Working

Have you looked at all the fuses for a blown one? Or a wire off a gauge or switch behind the dash?

Don S has posted a troubleshooting guide for trim systems (I think) a few times, try a search. But that will require taking some readings.

 

[wcsparky05]

Re: Temp & Trim Gauges Not Working

thermostats get old and stuck. replace that. <$10. that will prob. fix that. trim/tilt does work, just not the gauges? i would check the wiring. maybe just a loose connection.

 

[CharlieB]

Re: Temp & Trim Gauges Not Working

First thing to look for is what is the common factor to all 3 guages.



Ground They are all in the dash and all grounded thru the same black ground wire.

Check under the dash and see if the main harness black lead goes to a common connector, take it apart, clean and reattach.

Got to the battery, clean and tighten all grounds

On the engine, clean and tighten the battery ground cable, ditto for the main harness black lead where it grounds to the engine.

Turn the key on and retest.

Done, you just saved at least 1 hour of the local marine shop labor bill.

If I drank beer I'd say you owe me one, go drink it for me.