mercury instrument wiring

[YN2(SS)]

I have remotored my boat with a 1980 Mercury 70 with version A PTT (2 hydraulic hoses to each of two cylinders and a remote mounted trim pump) and it came with a remote control that I believe is not the exact correct one (with a trailering button) but I believe will work. The Mercury remote control has an instrument wiring harness that plugs into the aft end of the control box. The five hole plug is labeled A to E and has five wires coming out of it. The following plug holes are labeled as follows with the corresponding wires.
A - purple
B - gray
C - tan
D - black ( I believe this goes to ground each of the instruments)
E - brown/white stripe (I believe this is for a trim gauge)

I have schematics but can't find what the purple, gray or tan wires are for. I am hooking up a tachometer, voltmeter and each gauge is backlighted (Faria dress white gauges). Does anyone know what these wires are for traditionally? If they are hooked up wrong, can it damage my new gauges? I dont plan on hooking up the trim wire as we are not installing a trim gauge.

Thanks!

 

[Chris1956]

Re: mercury instrument wiring

OK, the five wire plug is for the motor right? It is not the trim harness, right?

Purple is usually +12VDC to run gauges, Grey is tach sender, black is ground, tan was overheat, but I did not think your motor had that feature. I did not think you motor had a trim gauge either. Are the controls "native" to the motor?

PTT harness is three wire. Red for power, green for down and blue for up. A purple was used to connect in the trim limit switch. By now the trim limit switch is likely bad. it is located on the starboard trim bracket.

 

[j_martin]

Re: mercury instrument wiring

The five pin plug is the dashboard harness connector. Wires go to the instruments. (tach, trim, and temp alarm.)

 

[Chris1956]

Re: mercury instrument wiring

Does his motor have a trim sender and overheat alarm?

 

[j_martin]

Re: mercury instrument wiring

Does his motor have a trim sender and overheat alarm?

I don't know, but the controls would have the wiring in place and use common connectors. Unused circuits are no big deal.

 

[YN2(SS)]

Re: mercury instrument wiring

Thanks all for the response. Firstly, I am confident that this remote control is NOT native to the outboard. The motor is a 1980 Mercury 70. That I am confident. It is mounted on a PTT system that has a remote mounted pump and two cylinders, is not correct for this year, but probably for a few years earlier. The trim limit switch is actually mounted outboard upper on the port(left) hyd cylinder bracket. And the 4 wires going to the pump are green/white(down trim), blue/white(tilt up trim), purple/white(up trim to the limit switch) and brown/white(?)(trim position sender).

The remote is a Mercury Quicksilver box and I am having my salvage yard guy determine of exactly what vintage and if it will work. It has a trim up and down switch but no trailer button and it seems like it wont allow the carb cable to reach full travel inside the cowling. If I can make this one work, I will just mount a trailer button somewhere.

The 5 hole pluge (A-E) harness I am referring to plugs in the back of the remote control box and I am sure it is an instrument cluster wiring harness. According to the schematics for with and without trim, E - brown/white stripe would be for a trim gauge. D- black is for ground. So if I gather correctly than is ???
A - purple is 12VDC power for the backlighting on the gauges? And maybe voltmeter too?
B - gray is tach?
C - tan is for overheat? (maybe?) Im not sure if this motor has a temp sender either. Serial #5651730. How could I find out?

I am wanting to hookup the tach (gray?), backlighting for all of the gauges (purple?), ground for each gauge (black?) and voltmeter (purple as well?). No trim gauge or temp overheat (I am installing a water pressure gauge (30 psi). Thank you very much for your help!!

 

[Don S]

Re: mercury instrument wiring

Post a picture of your control so everyone knows what you are working on.