This is a Gen IV 454 and a Thunderbolt 5 with knock sensor. I am trying to figure out where all these wires go as this is an engine swap with a new harness as the last one was quite butchered.

I've got a few I can't figure out so here you go!

purple/wht stripe in the motor harness near the coil.


purple/yellow stripe goes to what color on the alternator?


white from the dash that is in the same bundle as all the wires going into the motor harness.

brown/white stripe and black near the coild in the motor harness.


2 sets of wires from the transom assembly (1986 Alpha):
1st set: 2 black wires 1 with red sleeve 1 with green sleeve


2nd set: 2 black wires 1 with red sleeve 1 with blk sleeve.

Finally, how do I wire the shift interrupt? I see a black lead and a wit/grn lead on the switch but where do I run wires from the two terminals?

Thanks,
Ken

Get the Merc manual and it will spell it out very clearly. If you can waite and post this after the 30th I will email you when I get home.

Jon

Ken, sorry can't help much. It appears you are mixing matching a newer motor harness to an older engine compartment harness. I have an Seloc Mercruiser manual for '86 models that has several different wiring diagrams that I'm sure would help a great deal with the 2 sets of trim wires, but it would make more sense have the book and the boat in the same place. An ohm meter would do wonders here. Or someone who has an alpha drive in your year, that could eyeball it for you. Once you know which is the trim limit, and which is the trim sender, that may help limit some of the possibilities.


from my Merc service manual that covers 90-94.......


These 2 wires are labeled, but not shown.

purple/wht stripe in the motor harness near the coil.
<Trim- "trailer" switch>

purple/yellow stripe goes to what color on the alternator?
< Ballast bypass wire>



white from the dash that is in the same bundle as all the wires going into the motor harness.

< white is now purple, See if under dash you have a white wire going to all gauges. This is a 12v switched wire. Goes to (+) side of coil and to alt. (purple wire)>


brown/white stripe and black near the coil in the motor harness.
<brown/white= oil temp sender, black is ground>


2 sets of wires from the transom assembly (1986 Alpha):

1st set: 2 black wires 1 with red sleeve 1 with green sleeve
2nd set: 2 black wires 1 with red sleeve 1 with blk sleeve.

< All of my manuals do not show these color sleeve combos. Guessing they must be the trim limit and the trim sender wires>


Finally, how do I wire the shift interrupt? I see a black lead and a white/grn lead on the switch but where do I run wires from the two terminals?

<black goes to a ground, white/green goes to the white/green terminal on distributer>

my book blu-knock sensor. pur-wht timing lead. gry- distributor to neg. on coil and to harnes to dash. blk- ground. and three pur- two from distributor one from coil join together on pur-on alt.and harnes to dash. tan-blu audio warning system . lit blu-oil pressure. tan- water temp.brn-wht trim sender. wht-red distributor to module. wht-grn distributor to module. hope you get it . James

purple/wht stripe in the motor harness near the coil.
RE: Oil temperature sounded good till I remembered there aren't enough pins in the harness plug to accomidate it?

purple/yellow stripe goes to what color on the alternator?
RE: Couldn't find reference to that wire anywhere

white from the dash that is in the same bundle as all the wires going into the motor harness.
RE:Maybe connects outside harness to something. Oil Temperature? Proably not hooked to anything in dash. Spare wire status.

brown/white stripe and black near the coild in the motor harness.
RE: Brown-White to Purple Sleved Trim Sender Wire from gimbal

2 sets of wires from the transom assembly (1986 Alpha):
1st set: 2 black wires 1 with red sleeve 1 with green sleeve
RE: Purple sleve and blue sleve are trim limit switch Purple to purple-whiite on the trim pump and Blue to Blue-white

2nd set: 2 black wires 1 with red sleeve 1 with blk sleeve.
RE: Purple Sleve to Brown-White and Black Sleve to ground

Finally, how do I wire the shift interrupt? I see a black lead and a wit/grn lead on the switch but where do I run wires from the two terminals?
RE: White-Green to post on distributor and black to ground

That's by best shot at it, good luck