is adding a tach a diy job

[fonthillhdtv]

I have a 1979 merc 4 cylinder 80hp I have been having some bogging down problems and would like to add a cheap tach. is it something thats relatively easy to install. Is there a certain type of tach i should be looking for. I found one called a tiny tach that is relatively inexpensive .I think this one is the one I need correct me if I'm wrong.TT226R-2XLR * Most multi-cylider outboards.
* Note: You can reset. 36.95

 

[achris]

Re: is adding a tach a diy job

Fitting a tach is quite easy.

You should only need 3 wires, power, ground and signal.

Power should be switched through the key so it's not draining while the engine is off.

Depending on which control box you have, Merc make a harness that has all the right wires for connecting to a tach.

Post a photo of your control box and I should be able to get something worked out for you....

Chris...........

 

[fonthillhdtv]

Re: is adding a tach a diy job

this is what my control box looks like I hope this helps

 

[Silvertip]

Re: is adding a tach a diy job

While Tiny Tach is the easiest to installed, it contains an internal battery that is good for five years and is not replaceable. So $36.00 gets you five years of operation. $36.00 is also close to what a "real" tach costs and will last as long as the boat.

 

[achris]

Re: is adding a tach a diy job

Right, your control box is the old style Mercontrol.... Easy!!!

At the front of the control box is a small rubber connector... It has 3 female blade connections inside. One power, one ground and one is the tach signal....

You have 2 options....

1. Go to a Merc dealer and buy a tacho harness for that control box... not expensive and makes the job easy and neat.... or

2. If you're a cheap bastard like me... get 3 male blade connectors and make your own harness with a length each of black, purple and gray wire....
To find out which connector is which.... plug the big harness connector into the engine and meter from the engine block to one of the connectors in the front of the control... look for no resistance.. that's the ground.... now put your meter on the gray wire on the rectifier in the engine.... It's connector at the front of the control box is the tacho signal.... the other one must the the power....

Chris............

 

[fonthillhdtv]

Re: is adding a tach a diy job

are all tach the same or do i need a specific tach for this motor

 

[achris]

Re: is adding a tach a diy job

Just one that will accept a '12 pole alternator' signal.