Re: rectifier -tach issue

[procraft built]

Re: rectifier -tach issue

Hey I'm I'm new to this.. I been trying to figure out how to start a new post or something. I have a 75 mercury inline 6 90hp on a 1985 pro craft 1650 the boat has a medallion tach in it only has a pole says (send) and a pole that says (gnd) I have the send side hooked to Brown from motor and ground hooked to ground. The ground also is ground for the light witch it has a blue wire running from my switch on dash to turn on lights.. can anyone please help I have redone the whole boat and only thing I don't have working is the tach. The boat use to have a 83 mercury inline 6 115 on it but I put my wiring harness and motor on it... Please any help thanks

 

[Chris1956]

Re: rectifier -tach issue

Re: rectifier -tach issue

The two Mercs use the same signal to power the tach. Do you know if you are getting an AC signal out of the stator when the motor is running? I would disconnect the rectifier and then test the tach with the motor running. If you have a signal from the stator, and the tach won't work, perhaps it is incompatible or bad.

 

[procraft built]

Re: rectifier -tach issue

Re: rectifier -tach issue

how do I check that ? I got a brown wire from motor that use to be in the control box but I took all wires out of it and put me a key on the dash my choke wire is gray I have it to a push button so I can use it so only wire I have not hooked to switch is a brown so I hooked it to the send part on the tach and had the ground hooked up also and no reading I just crank the boat unhooked Brown from tach and made a jumper from yellow on switch back to tack on send side and still Nuttin althat was with motor running the tach worked good with the 115 on the boat but it blew up so got the 90 for free can't beat that deal ! Also there is a dial on back of tach says 1 2 3 4 what should I have it on QUOTE=Chris1956;4561223]The two Mercs use the same signal to power the tach. Do you know if you are getting an AC signal out of the stator when the motor is running? I would disconnect the rectifier and then test the tach with the motor running. If you have a signal from the stator, and the tach won't work, perhaps it is incompatible or bad.[/QUOTE]

 

[gbrowne9]

Re: rectifier -tach issue

Re: rectifier -tach issue

if you are using the 1975 control box there is a 3 prong plug at the front of it for the tach. a power ,a ground and a sender.i think the brown wire you are talking about is a power wire.if you have a test light the sender wire will pulse.i think the sender wire was off white but i can,t remember so test that plug.

 

[procraft built]

Re: rectifier -tach issue

Re: rectifier -tach issue

I have the 75 control box but all the wires I have took out of it and put them in key switch on the dash now the Brown wire has no voltage on it nor does any wire have a pulse goin on or at least I could see what does the yellow wire in the bundle control or does it do ? And what does the 1234 on the back of tack mean ?

if you are using the 1975 control box there is a 3 prong plug at the front of it for the tach. a power ,a ground and a sender.i think the brown wire you are talking about is a power wire.if you have a

 

[Chris1956]

Re: rectifier -tach issue

Re: rectifier -tach issue

Brown wire is tach signal. White wire is power wire, black wire is ground. The settings on the back of the tach are for different motors. I have no idea which setting you should use. I would start with 4 and work downward.

 

[procraft built]

Re: rectifier -tach issue

Re: rectifier -tach issue

Alright thanks ill try that its on setting one now so ill just go threw the #s and if I hook up a volt meter to the brown wire should I get any thing showing up ?

 

[gbrowne9]

Re: rectifier -tach issue

Re: rectifier -tach issue

the 1234 on the back of the tach are for the number of poles in your alternator. set it to number 4 ,should be for 12 pole which is what you have.

 

[procraft built]

Re: rectifier -tach issue

Re: rectifier -tach issue

Ok should I pick anything up on brown wire with a volt meter ? And if so what should I set the volt meter on to pick up anything

 

[Chris1956]

Re: rectifier -tach issue

Re: rectifier -tach issue

Set the voltmeter to AC and start with a high voltage range. Reduce the range until you see a voltage. If you get AC voltage, the stator is good. Disconnect the rectifier from the stator to remove that variable from the equation.

 

[procraft built]

Re: rectifier -tach issue

Re: rectifier -tach issue

Ok ill give that a shot and see what happens when I get back in town on vacation with family now thanks all yall so Mich for the help