Wiring harness problems

[mrdoug]

I have a 1982 Mercury 80 HP outboard with a Quicksilver side mount remote control unit (no model # on unit). Wiring work was obviously done by some previous owner. I have totally reconditioned the interior of the boat. I took pictures of the wiring with my cell phone before I disconnected the control unit and all the switches. However, wait for it, my cell phone flew off my motorcycle and was run over several times before I could retrieve it. Bottom line, no photos to work from. When putting things back together and trying to follow color coding of wires, some of the wires were replaced without any care in matching color coding. My problem, generally speaking, is I have 6 wires on the ignition switch (MP41070-2) and 8 wires in the wiring harness. At the switch, 2 wires (gray and tan) from the harness have no place to go on the switch. Where do they go? At the motor, the purple and tan are dead ended - not connected to anything. It is apparent that the wiring harness was replaced at one time because all the wires are sliced with after market male/female plug in connectors. If the tan wire is not connected at either end, what should it be connected to? Complicating the situation, there are 7 wires coming out of the control unit - 3 from the backside and 4 from the rear end of the unit. These 4 (2 green, 2 yellow) obviously are not original. I have no idea what they go to inside the unit and I don't think I want to explore that first hand. I have considered replacing the remote control unit since it comes with the cable, but it's a big expense. Any ideas or suggestions?

 

[alldodge]

Without getting into all wires, the below list standard wire colors and what they are used for. Things like Gray is the tachometer and Tan is water temp




Being a 82 its a 2 stroke correct?

 

[mrdoug]

Without getting into all wires, the below list standard wire colors and what they are used for. Things like Gray is the tachometer and Tan is water temp

View attachment 336197


Being a 82 its a 2 stroke correct?

You are correct, it's a 2 stroke.

 

[alldodge]

Wiring

 

[mrdoug]

Alldodge, thanks for your response. I just want to be sure the first diagram for 45-50 HP engines applies to my 80 HP and the 2nd diagram for 76-78 engines applies to the 80 HP also. Right? Is it possible to buy the wiring harness connector so I can get rid of all the splices? If so, where?

 

[alldodge]

Without having the service manual, for the most part yes

There could be some changes, but use it as how it works unless you see issues with original wires or connections. The colors stay the ame for what they are used for. Try to see if things work and if not, ask and hope others with more experience can help, but I'll be here all the same

 

[Buckischloo]

I believe CDI Electronics makes replacement wiring harnesses for both engine and boat side for Mercs. If your engine wiring is brittle and corroded, a new harness is the way to go. Otherwise, the splices may not seem as bad if cost is an issue. You would want to solder and heat shrink the connections. I have a number of older Mercs so I invested in a collection of marine wire in the appropriate colors and guage to save money when re-wiring.

 

[mrdoug]

Buck, thanks for the info. I book marked the CDI catalog for future use. You mentioned color coded marine wire. What's a good source for that?

 

[Buckischloo]

I shopped around for Marine wire on the internet to get all the colors I needed. I got the colors shown on the wiring diagrams to keep things close to original. WiringProducts and Bestboatwire. I also bought a supply of the appropriate flanged spade and ring terminals and used a good crimper and heat shrink to make the replacements. I remember attaching to the factory plug was tricky as all of the insulation would disintegrate up to the plug. Somehow I got one motor fixed and will work on the others as I need them.

 

[Buckischloo]

For one motor, a new harness may be the easiest way to go But then, what fun would that be?