"Ryan and William, Most merc C
"Ryan and William, Most merc Controls are the same. I used the controls from my '77 merc 1500 on my '93 Merc 135HPV6.
Ryan and William, you both need to worry about the wiring. The wiring may be different, however, it can be made compatable, since the '77 wiring harness functions the same as the later models.
William, You will need to make a wiring cross connect diagram. The wire colors on that Merc 1500 are:
White : +12V to the switchbox (idn accessory)
Black ground
Red +12V hot at all times
Grey Choke solenoid
Brown tach signal
Yellow Starter solenoid
orange(or salmon) is ignition killer not used on your motor
Ryan, You wire colors may be the same as Williams, except you will use the salmon or orange wire to kill the ignition."