Wiring harness info

[old islander]

Hi All,
I'm in the process of restoring my 1977 StarCraft islander. I just finished the rebuild on the motor and will soon be returning it to it's home in the hull. I bought the boat a few years back and over the years po's have butchered, spliced, taped, repaired with lamp cord, cut, abused and melted a lot of the wires in the boat. The boat has a 120HP 153CI mercruiser in line 4 serial#4511052 with an MC1 outdrive serial#2970347. I would like to replace the 37 year old wires with new. I found a lot of harnesses on line that were called "old style" harnesses. How can I desifer what harness I need. Does it go by pin count? They all have different part #'s. Can I find this info in one of the merc manuals? Any help would be much appreciated.

 

[Grandad]

Re: Wiring harness info

Are you planning to replace the engine and gauge wiring harness or the boat's wiring or both? I would expect that most of the previous transgressions were done to the boat wiring system, not the engine wiring system. Unless the engines wire harness has been abused somehow, I'd leave it alone. I have no problem with my 1972 120 HP engine wiring. The only thing I did to this harness was to add a stainless steel gear clamp to the plug at the engine and to the plug hidden near the gauges. I did this after trouble-shooting a loose plug hidden in the sidewall of my Holiday. I doubt that you will find a harness specifically made for your boat's wiring system. I'd recommend making your own. Even if you find a suitable harness, most of the work will be making the terminations at each end anyway. - Grandad

 

[old islander]

Re: Wiring harness info

I was looking for the harness that goes between the dash and the pin connector at the motor. I was hoping to get a new pin connector end and figure the rest out with the wiring diagrams from my manuals. I believe it's a 9 pin, however I will have to verify that next time i'm at the boat. I guess a universal harness is just a pipe dream.

 

[gm280]

Re: Wiring harness info

There are places on the net that do such harness work, but they are certainly not cheap either. Custom replacement (or after market) harnesses are available but are also usually custom made to your specs. You could buy some quality weatherproof connectors, and of course the needed colored wires, and make them yourself. I actually did that for my replacement on my '76 Johnson 40 HP harness on the OB. I bought the original wire connectors which are still available and easy to find, and replaced all the wires and built a new harness for that OB. And after reviewing the connection harness between the OB and dash setup, I'll probably be doing that for that harness as well... Not hard, but time consuming!

 

[Fishermark]

Re: Wiring harness info

I have replaced a couple of wiring harnesses over the years with harnesses I found on ebay. Most of the ones for sale have pictures of the ends... just make sure they look like yours. Not a terribly difficult job.

 

[998cc]

Re: Wiring harness info

I was looking for the harness that goes between the dash and the pin connector at the motor. I was hoping to get a new pin connector end and figure the rest out with the wiring diagrams from my manuals. I believe it's a 9 pin, however I will have to verify that next time i'm at the boat. I guess a universal harness is just a pipe dream.

Do you have a picture of the plug you are trying to match? I have one from a donor engine, a 165HP inline L6, that may (or may not) fit.

Russ
998cc

 

[old islander]

Re: Wiring harness info

Do you have a picture of the plug you are trying to match? I have one from a donor engine, a 165HP inline L6, that may (or may not) fit.

Russ
998cc

I do not at this time. I'm in Wisconsin, and the boat is covered in the yard with roughly 16 inches of snow on it. The last week here temps have been between -16 and -8 with 40 to 50 below zero wind chill factors. I may not be able to get a pick inside the boat till spring....

 

[Bondo]

Re: Wiring harness info

I was looking for the harness that goes between the dash and the pin connector at the motor. I was hoping to get a new pin connector end and figure the rest out with the wiring diagrams from my manuals. I believe it's a 9 pin, however I will have to verify that next time i'm at the boat. I guess a universal harness is just a pipe dream.

Ayuh,..... I believe you'll find the biggest variable in those harnesses is 2 things,...

The Vintage, 'n the Length,....

I'm pretty sure the pin count changed as Merc changed vintages, not so much motor type or family,....

'n of course Length is self-explanatory,... a harness for a 14' hull won't fit a 22' hull, too short,...

I'd think the manuals would work better than a trip to the boat,...
Ya already know yer startin' out with a 1977 vintage,...
The manuals of newer motors, should point out when yer harness became Obsolete, if it has,...

 

[littlebookworm]

Re: Wiring harness info

Whatever you do, just remember to use marine grade wire and connectors. The stuff you can buy at Home Depot or Lowes or such will not last in a marine environment. I had to rewire much of the boat when i rebuilt a 1980 24' Classic (manufacturer's name) cruiser. I replaced much of the harness from the dash to the engine and parts of the engine wiring harness. The plastic flexixible wire harness covering , slit on one side, is much better for protection than just running electrical tape over the harnesses. That covering can be found in most auto parts supply stores. Remember to support any harnesses at regular spots so there's no strain on the wires. Follow the color code and wire size charts to prevent problems later. Good luck. Hy