tach not working??????

[greg r]

i am having trouble with my tach, it will not work, i have a 1994 johnson 40 hp, i have changed the tach, rectifier(200.00) even ran new wires, it zero's when i turn the key on, but when i start it, nothing?????? help, i can't keep guessing where i am on my rpm's.<br />greg

 

[javsam]

Re: tach not working??????

are you running a wire from tach to yellow/brown wire on rectifier? On rectifier should be 3 wires,two that are solid yellow and one that is dual colored-yellow/brown or yellow/gray.<br />javsam

 

[Silvertip]

Re: tach not working??????

There is a connection just below the key switch and throttle tension knob for a tach. Three wires -- ground, 12v and sense.

 

[greg r]

Re: tach not working??????

my rectifier has 5 wires, about 2"w x 4"h with a heat sink, <br />1. yellow<br />2. yellow/grey<br />3. grey<br />4. purple<br />5. red (heavy guage)<br /> I have connected the grey from the tach to the yellow/grey coming from the stator,tach works,hook my meter to the battery, voltage will go above 14v while moving, i went as far as running 3 NEW wires from the motor to the tach , and nothing, i have not ever seen a rectifier/reglator that looks like this one,my 1993 evinrude 60hp has the same one and it works,swapped them around ,works on the 60,not the 40???????

 

[MCM]

Re: tach not working??????

Voltage above 14 volts is normal it just means that the charging system is working, a spike above 16 volts would be a cause for concern. What happens with the gray tach wire conneccted to the gray wire at the rectifier?

 

[greg r]

Re: tach not working??????

i just took a reading with my meter(fluke 7-600)<br />at the grey wire at rectifier(red lead) and engine ground(black lead) reads 10.39v at idle, engine ground to purple wire 13.49v, idle. any ideas would greatly help! (i am needing to re prop, that is why i need my tach so bad)

 

[MCM]

Re: tach not working??????

I meant does the tach work when hooked up to the gray rectifier wire, I'm pretty sure thats where it should be.

 

[greg r]

Re: tach not working??????

no,it does nothing but zero out when i turn the key on. When running nothing. i know that it is hooked up correctly......?<br />black wire to ground<br />purple wire to ign. <br />grey wire to sender<br />the tach is a new omc unit

 

[greg r]

Re: tach not working??????

here is a pic of the rectifier,well how do i post it??

 

[MCM]

Re: tach not working??????

Is gray send wire from the tach/control box connected to the gray wire from the rectifier at the terminal strip? you may need to get an OEM service/shop manual which will contain the proper wiring diagram for your motor if you haven't got one already, if you need diagrams/parts lists for your motor you can go to iShopMarine.com to find them.

 

[javsam]

Re: tach not working??????

is the the black wire on the tach connected to the negative side of the battery?<br />javsam

 

[Seasport]

Re: tach not working??????

Is the purple wire to the rectifier/regulator hooked up to the 12V from ignition? It needs to be to get the voltage sender pulses on the grey wire.

 

[Seasport]

Re: tach not working??????

See <br /> http://www.iboats.com/cgi-bin/ubb/ultimatebb.cgi?ubb=get_topic;f=28;t=037914#000005

 

[greg r]

Re: tach not working??????

yes, i followed the wiring in the manual,i have an additional ground wire dirctly to the battery to the tach(for testing),and i also have 12.60v at the purple wire on the tach?????

 

[Seasport]

Re: tach not working??????

You have replaced about everything but still no luck. Hmmm. You mentioned that the tach worked when you connected the grey send wire to the yellow/grey wire from the stator(you could leave it like this). Also your tach is zeroing when you turn the ignition on which means the 12V ignition and ground connections are probably OK at the tach. These both suggest that the problem is with the grey send wire coming out of the rectifier/regulator. (Hence my suggestion to check that you have 12V on the purple wire going to the rectifier/regulator - are you sure this is fed from a 12V source).<br /><br />Measure the voltages right at the tach between the ground terminal and the others. You should have 12V on the IGN terminal (with the keyswitch turned on) and you should be able to measure an AC voltage at the SEND terminal of more than say 5V with the motor running. (Remember to have your meter set to measure AC voltage.) If you can measure a voltage on the SEND terminal the tach should be working. If you can't, trace back through the SEND circuit and find the problem.<br /><br />Also check that you have a good earth connection, measure the continuity between the GND terminal and the battery -ve terminal.

 

[greg r]

Re: tach not working??????

i have cleaned and tightend evrey + and - connection, and as i posted previously, i have ran new wires to the tach from the terminal block, even have the tach back by the motor ,not in the dash(for testing), tach is new,regulator is new, i am getting 13.5v between the + and - on the back of the tach, and 10.4v at the grey wire, tach is set on 2cylinder, and it is a 2 cycle tach, help! surely the stator isnt going bad,it runs fine at all rpm..??

 

[MCM]

Re: tach not working??????

What brand of tach is it? does it have a setting for 5 or 6 pulse?

 

[MCM]

Re: tach not working??????

Also what is the model# of the motor? they used different rectifiers depending on the model of the motor.

 

[javsam]

Re: tach not working??????

my 1990 johnson 40 hp has a 10 pole alternator, therefore my tach setting is at 5 pulses.seems to me, your tach should be set at 5 too.<br />javsam

 

[MCM]

Re: tach not working??????

EDIT