Installing a tachometer older 40hp outboard

I am wanting to install a tachometer on my early 90s 40hp 4 cylinder 2 stoke Mariner outboard. I have a QuickSilver control that has a wiring harness to plug a tachometer harness into, but I am not sure which one to get. The guy I bought the motor from had a tachometer and harness, that was a direct plug in, tachometer only had three terminals on the back, but he did not want to part with it. Could I get a harness and use any aftermarket tachometer, the ones that have a selector on the back for "pole" setting? Is so, what pole setting do I use?

Thanks for your help.

Any aftermarket tach will work,and set to 6P if the number below 582399,above 4P.

I have another question that I hope someone can help me with. I am trying to figure out the tach/accessory harness wire colors on my Quicksilver control box, with key switch, and power trim. I order what I thought was a 5 pin plug and play harness, but it ended up being a 4 pin instead, so I am to bypass the plug and hard wire it. The colors on the control box are Black, Tan/Blue, Purple, Gray, Brown/White, and a tan wire that is off to the side and not in the harness plug.

Purple = 12+
Black = Ground -
Gray = Tachometer Signal

Is this correct?

TGBTG7701 said:

I have another question that I hope someone can help me with. I am trying to figure out the tach/accessory harness wire colors on my Quicksilver control box, with key switch, and power trim. I order what I thought was a 5 pin plug and play harness, but it ended up being a 4 pin instead, so I am to bypass the plug and hard wire it. The colors on the control box are Black, Tan/Blue, Purple, Gray, Brown/White, and a tan wire that is off to the side and not in the harness plug.

Purple = 12+
Black = Ground -
Gray = Tachometer Signal

Is this correct?

Click to expand...

Sounds correct to me. BTW the proper harness for the 5-pin connector on the later-style control boxes is 86396. Attached is a pic of the instructions with a connection diagram that confirms your wiring.

HTH..........ed

You are correct.The tan is the temperature gauge,the tan/blue is temperature warning horn