1977 Mercury 1500

[Abaxter12]

I have a 1977 Mercury 1500 outboard. It fires right up and was verified by a boat mechanic but I don’t have a control box or the electrical harness to run from the control box to the outboard. Does anyone know how to get one of those setups? Or is anyone interested in the outboard? If it’s too hard to find I’d rather sell it to someone and look for something newer

 

[Chris1956]

Control boxes can be any Mercury compatible one you can find. I am using the MerControl from my '77 on my '93 Merc. The shift and throttle cables are the same.

Boat harnesses are available on the web for $$. You could make your own from wires colored red, white, black, grey, yellow and brown. You simply cut lengths of each and tape 'em together. Solder one end of all but the brown wire to the terminals of an ign switch, and connect the other ends to the engine harness. The brown wire is the tachmeter signal wire.

Check the engine harness. If not replaced, they are usually bad by now.

A wiring diagram is on the maxrules web site.


BTW- That 1500 is a thoroughbred. It is a bit finicky, but will be real fast and powerful from mid-range up to WOT. Bottom end power is a bit low, but she will pull until you hit the powerband and then wham...

 

[Abaxter12]

Thanks for that info! The mechanic that took it apart said it would be best to sell since parts for it are a little hard to find. I’m not very mechanical savvy so the info helps!

 

[Chris1956]

I do not think parts are hard to find. Tune up stuff like spark plugs, waterpumps, carb kits and the like are readily available. If you break some part of the motor, that is a bit more tricky, but the web is a wonderful thing for stuff like that.

Your mechanic probably never worked on one of those. He may not know how.

 

[Abaxter12]

Ok update. Found a universal adapter that can go from the control box to the motor (7 pin universal for a 6 pin side). New question: can I use a 7 pin control box and not use of the connections? Or do i still have to use a 6pin control box?

 

[Chris1956]

Your motor will have the quick disconnect on the starboard side of the engine. If the adaptor you bought fits that, they you have no issue. All Mercs of that era used 1 extra wire. On your motor it is the orange or salmon colored one. It will have a female connector in the boat harness, but no corresponding pin in the engine plug.

Just so you know, the 1979+ inline 6 motors switched to a distributorless ignition, and use the salmon or orange wire, but don't use the white wire(which your motor uses). Same boat harness, though.

 

[Abaxter12]

Thank you! This definitely helps!