Installing Gauges

[caper_45ca]

I purchased a 15' Princecraft with a 25hp rude...E25REOR.....the setup has factory wheel and side remote....I would like to install both an overheat alarm and a tach to help prevent a costly rebuild....after doing some searching I see that the tan wire coming from the head is the heat but still have no clue as to what to do with that wire to hook up alarm....also I read that the grey wire is for the tach...I cant even find a grey wire....any help would be greatly appreciated....Thank You

 

[Silvertip]

Re: Installing Gauges

For less tha five bucks you can buy an alarm at Radio Shack. They run on 12V. All you need is one wire that feeds +12V to the horn when the key is on. The other wire on the horn connects to the tan overheat sensor wire. That wire simply provides a ground should the engine overheat hence turning on the horn. The tach has four connections. +12V when the key is on. Ground, +12V from the light switch to provide night illumination, and the sense wire from the engine rectifier. The tach will have instructions with it.

 

[F_R]

Re: Installing Gauges

Not familiar with that particular engine, but isn't it a hand start? More than likely it does not have an alternator or rectifier, thus no grey tach wire. So a regular alternator-fed tach won't work on it. That pretty much limits you to one that picks up an induced signal from a spark plug wire. Like Tiny-Tach.

 

[caper_45ca]

Re: Installing Gauges

Thank you 4 the responses.....you are correct it is a rope start.....so this tiny tach will operate as well?....Also there is no key switch so the idea of wiring alarm +12v is also out....can an alarm still be hooked up?

 

[F_R]

Re: Installing Gauges

Tiny Tach has a website. Check it and see if that's anything you would want. Also check with a Evinrude dealer and see if perchance they have a factory accessory tach for that motor. I don't think so, but it won't hurt to ask.

Some other help needed from others more knowlegeable on this late model motor. Does it have S.L.O.W ? If so, you don't need a horn because it will automatically slow down to half speed if it starts to overheat. That is the warning something is amiss. My expertise is on older motors, so pardon the dumbness.

Update: I just looked it up. It does have S.L.O.W.

 

[Silvertip]

Re: Installing Gauges

If you don't have 12 volts to operate anything electrical you can't add a horn or a tach. Tiny Tachs operate with an internal battery so they don't need an external power source. You can however, add a water pressure gauge that would provide an indication that the water pump is working properly. It's not electric and although it won't warn of overheat, it will warn of a failing water pump impeller. Your best protection from overheating is priodic (every couple of years) replacement of the water pump impeller, and thermostat.

 

[ezeke]

Re: Installing Gauges

I think that you already have the temperature switch and just need a horn and battery to drive it. Connect the tan wire to the horn [negative]; positve battery terminal to the horn; negative battery wire to engine block.

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[ezeke]

Re: Installing Gauges

TinyTach can go anywhere. Here's one I riveted on a 1972 9.5HP.

 

[caper_45ca]

Re: Installing Gauges

Again thank You for the response.....I am going to put a battery in the boat so I can operate the running lights and a fishfinder....My plan was to charge the battery b4 each outing since they will draw very little power....Could the horn be also hooked to that battery source following ezekes instructions?....could a tach be also wired in?...or am I limited to the tiny tach idea?....Thank you

 

[ezeke]

Re: Installing Gauges

The problem with the regular tach is not voltage or lack thereof. You don't have a pulse or signal for a regular tach.

The TinyTach gets the pulse by sensing the spark current because the pulse wire is literally wrapped around the spark plug wires. I have mine up just under the flywheel, so you don't even see them. You also don't need a power source because it runs on its own internal battery.

You can use any battery current that is the correct voltage for whatever horn you use. The reason that you can do this without concern is that the voltage will only be used when the engine actually overheats. Otherwise, the circuit is never closed.

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[F_R]

Re: Installing Gauges

Well, if he uses the tan wire and temp switch for the horn, won't he lose the S.L.O.W. feature?

 

[ezeke]

Re: Installing Gauges

The temperature switch that has only a tan wire is strictly on or off, therefore whatever is connected to it is either grounded or not.

Temperature switches that control more complicated powerpacks such as those with QuikStart have additional wires.​

 

[caper_45ca]

Re: Installing Gauges

My engine has only 1 tan wire coming from the sensor...Am I correct in assuming that if I splice into this wire and go directly to the - side of horn..then from + side of horn to +12v batt. then from - side of 12volt batt to ground on engine the horn will sound if the engine overheats? Will this have any adverse effect on any of the electrical components like powerpack?....also could this circuit b tested by grounding out the tan wire?thank You

 

[ezeke]

Re: Installing Gauges

Yes, no, yes.

Edit: Test the horn connection by disconnecting the lead from the temperature switch and grounding the lead wire.

 

[caper_45ca]

Re: Installing Gauges

Thank you very much 4 the info....Im going to do it....