Mercury 1150 tachometer settings

fishdog4449

Chief Petty Officer
Joined
Jul 16, 2007
Messages
462
Hey guys love this forum two quick questions here '76Merc1150
My new teleflex tach came in today and wondering if I should connect the sender wire from the plug on the front of the control box the controls (switchbox) or from the stator wires (alternator)?
Pole setting should be 6P right?

THANKS!!


here is the link to where i bought the tach
http://www.greatlakesskipper.com/productdetail.cfm?CatID=SS225&ProductID=10628
 

emckelvy

Commander
Joined
Jan 16, 2004
Messages
2,506
Re: Mercury 1150 tachometer settings

Your '76 should have a distributor-type ign, in which case this is the electrical diagram:

http://www.maxrules.com/oldmercs/Wiring/1966ona/50.jpg

The tach plug on the control box, as long as it's wired correctly and working properly, has all the connections you'll need for your tach.

You can check with a meter to determine which terminal is +12V; which is ground; and then the other is the tach signal from the brown wire connected to the rectifier.

If there were any problems with the plug, you could connect the tach's signal wire to either of the terminals on the rectifier where the yellow wires connect.

But you'd still have to find a source of switched +12V and ground. So, the tach plug sure is convenient and would be worth troubleshooting if it's got issues.

Your Merc has a 12-pole alternator, and according to the product description the tach has that as an available setting.

HTH.........ed
 

fishdog4449

Chief Petty Officer
Joined
Jul 16, 2007
Messages
462
Re: Mercury 1150 tachometer settings

Thanks, EM!!

I ended up finding another post that described how to wire an after market tach. All I had to do was move the brown wire on the engine from the terminal on the switchbox to the alternator post. Set the tach to 12P like you said and it works great!
I'm getting 950RPM on the muffs with a 300-400RPM cranking speed, will see what happens when I get to the lake on tuesday!
 
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