90 merc switchbox

[hrdhead]

Hi all,I just replaced the switch box on my '87 90 merc..the box has the same part number but this switch box has a black wire coming out of the black area on the front, my other had no wire at all..is it another ground?Thanks.

[Bob H.]

If it's black it should be a ground that you can attach to the switchbox mounting bolts. I have the same engine (80hp) and spare switchboxes but none with the wire you mention.

[Slipsinker]

For future reference here are the wiring color codes for Merc.

Mercury Outboard Wiring

The following color coded wiring is often seen in outboard motors with the Mercury or Mariner brand. This information was provided by Mercury Marine.
Table 3. Mercury/Mariner Standard Outboard Wiring Color Code, after a similar table from Mercury Marine. Color Function
Black All Ground
Brown Reference Electrode MerCathode System
Orange Anode Electrode MerCathode System
Lt. Blue/White Stripe Trim UP Switch
Lt. Green/White Stripe Trim DOWN Switch
Brown/White Stripe Trim Sender to Trim Gauge
Purple/White Stripe Trim "Trailer" Switch
Gray Tachometer Signal
Black/Yellow Stripe Shorting or Stop Circuit
Pink Fuel Sender to Gauge
Red Unprotected Wire from Battery
Red/Purple Stripe Protected (Fused) Wire from Battery
Red/Purple Stripe Protected (12 Volt +) to Trim Panel Control
Purple Ignition (Switch) to 12 Volt Positive
Tan Temperature Switch to Warning Horn
Tan Temperature Sender to Temperature Gauge
Tan/Blue Stripe Temperature Switch to Warning Horn
Yellow Starter Solenoid to Starter Motor
Yellow Starter to Regulator (Charging Circuit)
Yellow/Red Stripe Start Switch to Start Solenoid to Neutral Start Switch
Yellow/Black Stripe Choke (Enrichener System)
Green with Color Stripe Switch Box to Coil - Striped and Numbered
White/Black Stripe Bias Circuit (Switch Boxes)

Hope this helps.