Electrical schematic needed for 1981 Century Mercruiser 260

1981century

Cadet
Joined
Oct 5, 2011
Messages
22
I need an electrical schematic for my 81 Century 260 Mercruiser (350 GM motor) Breaker Point Ignition, pre alpha drive with power steering. serial number 5879069 I have some "extra wires" that I have no clue where they are supposed to go, but I think they are power trim related. I took this boat apart well over a year ago and I didn't label anything very well. I have always had one or two extra wires on this harness every time I have had this motor out, but I think at least one of these was hooked up when I took this boat apart. See photos of the extra wires. There are three wires without a home. One of the wires in question (shown in the picture), is black and disconnected from a pair of wires which are molded together, one side is still hooked up to the terminal on the shift plate, but the other half of it is not hooked up, and is actually laying on top of the open distributor in the picture)the wire has an eyelet on the end of it and also has a quick disconnect on it like the other half of this dual wire. My guess as to why I didn't disconnect in the same place, is that I was afraid I would confuse it with the other one that has the same type of connector. The second wire in question is purple with a white stripe. The third wire is black and comes out of the same harness as the purple and white wire. The photo didn't turn out so good, so I will get another one and post it as soon as my camara battery gets charged up. Thanks, I added another picture in Adobe. In order to see it correctly you may have to rotate it counterclockwise when viewing it. I put clouds around the wires in question on the picture. Any help I can get will be greatly appreciated. thanks again.
 

Attachments

  • IM006447.jpg
    IM006447.jpg
    145.7 KB · Views: 0
  • wires2.pdf
    286.1 KB · Views: 0
Last edited:

1981century

Cadet
Joined
Oct 5, 2011
Messages
22
Re: Electrical schematic needed for 1981 Century Mercruiser 260

29 views and no replies? Is the answer in the adult section, and I missed it? Can anyone help? It's only 3 wires! Doh!
 

achris

More fish than mountain goat
Joined
May 19, 2004
Messages
27,468
Re: Electrical schematic needed for 1981 Century Mercruiser 260

Do you have an ammeter in the instrument panel or a voltmeter?
 

Pete104

Lieutenant
Joined
Apr 30, 2011
Messages
1,439
Re: Electrical schematic needed for 1981 Century Mercruiser 260

Purple wire is your trim gauge & black is the ground for sender. There is a little nylon block fastened close to the main wiring harness that daisy chains the conections to the dash.
 

1981century

Cadet
Joined
Oct 5, 2011
Messages
22
Re: Electrical schematic needed for 1981 Century Mercruiser 260

Okay I think I understand your response, so the black wire (the wire in the picture that is loose and has an inline connector in addition to the eyelet should go to ground. Is one of the terminals on the shift plate a ground maybe, or are the black and purple wire supposed to be daisy chained together on the nylon block? The nylon block is there and I had both wires labeled with masking tape as going to the plate, but I don't remember having those two together but I have slept since then. Also there are two other wires beside the purple and black wire shown side by side. There is another black wire in the photo with some masking tape on it, (look above the purple and thick black wire) I have not hooked up the black wire in forever, and it may be for an old hour gauge. Also there is a brown wire that has not been hooked up either. The purple and thick black wire were hooked up prior to this motor pull and everything worked with the trim gauges. There could have been something haywire with the up button on the trim, as I vaguely recall possibly having to push both buttons in order to trim the drive up. I am attaching some better photos with notes. Thanks for the help.
 

Attachments

  • wires3.pdf
    179.7 KB · Views: 0
  • wires4.pdf
    287.3 KB · Views: 0

Pete104

Lieutenant
Joined
Apr 30, 2011
Messages
1,439
Re: Electrical schematic needed for 1981 Century Mercruiser 260

Thanks, Don for digging that up!
 
Top