Source for Wiring Harness Merc 85? Pic Included

[SeaKaye12]

Hello,<br />Well, I've started to poke around the "free" boat I got last week. The '77 Merc 850 seems promising. However, one horror I've noticed is the condition of the wiring. Like I've seen mentioned in posts here, the wiring on mine is brittle and corroded; especially in the area of the junction box. Here's a Picture.<br />

<br /><br />Qustions: (1)Are new wiring harnesses available; and if so...where is a good source?<br />(2) What would you say is the "level of difficulty" in replacing the harness(s)...Connections at the junction box are easy...screw terminals. What's the other ends like? <br /><br />I found a shop manual (sheer luck...I met a guy at the lake who's got the same engine as I have...and he's going to loan me the genuine Merc Manual. But, I'm still going to have lots of questions; assuming the parts are even available at some "reasonable" cost?<br /><br />Thanks, Chuck

 

[OperativeK]

Re: Source for Wiring Harness Merc 85? Pic Included

You need to talk with "Clams" or Wayne Canino.<br /><br />Here is his ebay:<br /> http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback&userid=clams_canino&frm=1728 <br /><br />I would bet he could find one, or may have one. You can click on right to view his items, he has an internal wiring harness for a IL6 right now. <br /><br />My boat was in the same condition and amazingly the wire still had good conductivity so I used battery cleaner and liqued tape and has been good since. You might want to try that.

 

[timmathis]

Re: Source for Wiring Harness Merc 85? Pic Included

Check with your local mercury dealer. They still have lots of parts available. But im sure Clams will have A good used one.

 

[Chris1956]

Re: Source for Wiring Harness Merc 85? Pic Included

SeaKay, You can buy this harness from an aftermarket source. If you look around a bit, you may find a better price. Start with http://www.oldmercs.com/starters.htm, then try https://www.surplusunlimited.com/Merchant2/merchant.mvc?Screen=CTGY&Category_Code=1550-100, and see if they have what you need.

 

[SeaKaye12]

Re: Source for Wiring Harness Merc 85? Pic Included

OK guys, thanks for the leads on parts. Now for the second half of the question...just how "do-able" is the job of replacing the harness?<br /><br />I have the manual that I was promised; it turned out to be a Clymer instead of the genuine Merc manual...but it's already been a big help none the less.<br /><br />Still...I would like opinions and tips . The connections at the junction box are simple screw terminals. What about the other ends of the wires? Will there be soldering/splicing anywhere? <br /><br />Will I have to remove the flywheel (sure seems so....) and if so...will I upset the timing adjustments?<br /><br />Do you think that running the engine with the wires in questionable shape is a big risk in terms of possible damage to expensive components like triggers and stators and coils? Remember; I'm itching to try firing it up to see just how good of shape it's in...<br /><br />Anybody want to give me a step-by-step on replacing the wiring harness? '77 Merc 850...<br /><br />Thanks again for reading...Chuck

 

[AMD Rules]

Re: Source for Wiring Harness Merc 85? Pic Included

If it were me, I'd leave the flywheel on, and inspect/repair whatever exposed wires & connectors are coming from the trigger/stator if required. Looks like the majority of brittle cracked wires you've circled are on your main harness, and that can be replaced relatively easily.

 

[joe belcastro]

Re: Source for Wiring Harness Merc 85? Pic Included

I made my own harness about a week or so ago. It took about 3 hours. I made a block diagram with the correct colors and their locations and then took digital pics as a backup. I bought all the wire, shrink sleeve, and eye connectors at home depot it cost just under $18.00. If you remove the old harness in tact use it as a model the new harness should be easy to make. I learned the hard way by trying to repair the old harness instead of making a new one. One of the corrodied wires shorted and took out the switch box ($235.00 for that part.) By the way I made the engine harness for 1979 Mrercury 700. Only involved 6 wires. Any questions and I'll be happy to answer.<br /><br />Joe B.

 

[SeaKaye12]

Re: Source for Wiring Harness Merc 85? Pic Included

Thanks Joe,<br /><br />Yeah; that'w what I was wondering...how hard could it be to just get some wire and do it your way.<br /><br />It's hard to tell where all the wires end up going and what sort of connections there are on the other end...<br /><br />In the pic; the wires that turn downward (left circle) seem to just go to the plug...<br /><br />The white wire (right circle in the pic)...travels upward to where I don't know yet.<br /><br />Did you replace all those with your harness? It looks like there might be two or three seperate harnesses...but until I take it all apart...or see one at a dealer...I can't really tell much.<br /><br />The wiring diagram in the manual helps...but it would be great if a dealer had a wiring harness (s) that I could pick up and look at. <br /><br />Most of the wires elsewhere on the engine look pretty good.....it's just the area around the junction box that look scary.<br /><br />Were you able to re-route all the wires without too much disasembly ?<br /><br />Thanks Chuck

 

[joe belcastro]

Re: Source for Wiring Harness Merc 85? Pic Included

Chuck,<br /><br />Start at the point where your battery cable comes into the motor, look at what you have to remove should be some small cover plate and 4 screws that hold the plug for the harness. Disconnect the plug then all the points where the wires are connected. Remember to mark down clors and locations. One the plug is disconnected and all the eye connectors are disconnected you can snake the harness back towards the plug with little effort. The harness just goes under the flywheel and should be no problem removing. <br /><br />Joe B.

 

[joe belcastro]

Re: Source for Wiring Harness Merc 85? Pic Included

Chuck,<br /><br />Start at the point where your battery cable comes into the motor, look at what you have to remove should be some small cover plate and 4 screws that hold the plug for the harness. Disconnect the plug then all the points where the wires are connected. Remember to mark down clors and locations. One the plug is disconnected and all the eye connectors are disconnected you can snake the harness back towards the plug with little effort. The harness just goes under the flywheel and should be no problem removing. <br />P.S. send me an e-mail address and I can send you pics of my harness before I removed it and where it runs through the engine.<br />Joe B.

 

[SeaKaye12]

Re: Source for Wiring Harness Merc 85? Pic Included

Thanks again Joe and all the others who replied earlier.<br /><br />I don't see any way if e-mailing you through this board; although the board FAQ talks of this being possible if a member sets it up that way. I looked at my set-up and yours (profile) and don't see what they mean./<br /><br />Anyway...my e-mail is cwwk at cox.net<br /><br />Substitute the @ for the "at"....my lame attempt to avoid spam...<br /><br />Thanks, Chuck