tachometer replacement?

[elanrw]

I bought my first boat, used 97 robalo w/150 hp merc outboard, a week ago. One of the things that didn't work was the tach. One of the connectors on the back were rusted off. There were four wires, five including the light. I lost the tach that I took out, but I thought I saw two ground connections on it. I wrote down the colors because I thought that the teleflex brand was direct replacement. Now I'm left with one too many wire. Can I make this tach work?

 

[OBJ]

Re: tachometer replacement?

Welcome aboard iboats elanrw!!<br /><br />Generaly speaking....<br /><br />The basic tach has three wires...<br /><br />Gray, which is the tach signal from the rectifier.<br />Purple, which is 12v DC from the ignition.<br />Black, which is ground.<br /><br />The old tach you took out may have had a separate leads for the light....maybe red and black?<br /><br />Post the colors you have and maybe we can give ya' some help.<br /><br />Thanks.

 

[elanrw]

Re: tachometer replacement?

Thanks OBJ<br /><br />The colors are two blacks, grey/brown, and purple.<br /><br />The blue/yellow went to the light.<br /><br />Here is a link to what I have, don't know what to put the range selector setting on???<br />Instruction does not make sense. <br />Seems to me that the max horse power for a Merc out board for the 7000 RPM Tach was 40hp???<br /><br /> http://www.tflx.com/pdf/obtach~1.pdf <br /><br />Already returned the new Tach and trying to find a direct replacement.