Tach not working

[clemsonfor]

I have been around for some time, not posted in a while but i have not had any problems. This is good and bad as it does not allow me to help others.

My common question which i have seen before is. I have a 1990 johnson GT 150hp.

What is the color of the tach wire under the hood? Is it connected to that bar on the starbord side of the motor? And what is the wire color on the ignition switch related to the tach?

The tach will sometimes work then it will just drop to the bottom like its off, sometimes it will then jump back into action but then die again. It usually will register as the motor runs but at a certain point usually a min or so after will just die off.

-Nate

 

[bignefan]

Re: Tach not working

tachs work off your charging system?maybe it's no charging all the time????

 

[clemsonfor]

Re: Tach not working

After reading some posts today i think i remembered that. Running yesterday i was running around 14volts on the dash meter so i think that is charging according to idiot gauge. I did not put a tester on it though nor do i know if i could, b/c its a fish and ski so the back deck opens foward, that would be impossible to open while WOT and then test the batteries in there. i dunno, that is why i wanted to know the wire colors that i need to know so i can test at idle and say 1200-1500rpms and off to see if i am charging or if the tach is actually getting a signal.

 

[clemsonfor]

Re: Tach not working

bump.

 

[Bob_VT]

Re: Tach not working

The tach wire is a gray wire in the control box and stays gray all the way back to the motor plug...... it is very easy to trace from there. I would check inside the control box and make sure the 3 wires are okay first.

 

[wilde1j]

Re: Tach not working

Grey=sense
Black=Ground
Purple=Switched 12VDC

 

[clemsonfor]

Re: Tach not working

Thanks for the replies. Just to clear the lingo up. I always assume control box to be the throttle ingnition combo in the boat which is how you control throttle. This is a javalen f/s, the ignition is on the dash and the throttle is on the side, but not in a "control box" set up. Or am i taking it wrong and control bos is on the motor and the wire then runs on the motor side of the plug.

I Beleive your talking about the dash wiring to the boat side of the plug just based on context what i know and the drawing. Just let me know for sure, but with that diagram i can start digging in the dash.

 

[wilde1j]

Re: Tach not working

The tach wire colors are consistent all the way back.