Merc 1400 tach hook up

[Jenason]

Hello
I installed a 1978 merc 1400 on my 97 bayliner runabout and am gaving an issue getting the tach to fire up
On the tach there is bat, gnd, signal
I jumped from the old control box and am pretty sure the wires are correct
Also i have 6 pole settings to choose from and tried most
Still no joy.
I ran the tach last year and worked great
ThAnks
Andy

 

[wired247]

Re: Merc 1400 tach hook up

Run the tach off one of the the rectifier yellow leads. You will have joy.

 

[Jenason]

Re: Merc 1400 tach hook up

So run the signal wire from the rectifier on the engine
Right?
Thx

 

[wired247]

Re: Merc 1400 tach hook up

Yep. Thats it.

 

[Chris1956]

Re: Merc 1400 tach hook up

Jenason, If the tach worked last year, the wiring should still be OK, no? You should already have the brown tach signal wire connected to one of the yellow stator wires, at the rectifier. Maybe the rectifier is bad? See if it charges the battery when it is running.

 

[wired247]

Re: Merc 1400 tach hook up

I think he is saying the tach worked with the old motor but he cant get it to work with the '78 1400 he just installed on his 97 bayliner. Thats certainly not the original motor. He was trying to pull a signal off the ignition system instead of the charging system.

 

[Chris1956]

Re: Merc 1400 tach hook up

Thetach signal on that '78 should have been wired to the rectifier at the factory, I would think. The older models were wired to the switchbox.

 

[wired247]

Re: Merc 1400 tach hook up

If its anything like my 1500 it had no tach wire at all in the harness.

 

[Chris1956]

Re: Merc 1400 tach hook up

My '73 850 had the tach signal wire. It was connected to the brown post on the switchbox, opposite of the distributor connections. I moved it to the rectifier. Maybe your 1500 has had some "upgrades" over the years.....

 

[wired247]

Re: Merc 1400 tach hook up

No wire at all in the harness that plugs into the side of the engine cowling. No wire, no connector etc. There was a hole there but nothing to connect the wire inside the motor cowling to the tach. I had to run one.