Engine swap electrical questions

[Steven D]

Patient - 1969 Sea Ray 185 with 160 inline 6 (bad) and old one drive (serial #2614325) I've been told it was good.

Donor - 1979 Marquis with 165 inline 6 and second generation one drive (serial #5359131). I've had this combo on the lake and it runs good. Rotten transom and floors...

So far I've gotten the 165 mounted in the Sea ray, so much for the easy part...

The electrical connections on the two boats while being the same size, have a different pin configuration. 160 has 2 large pins and 6 smaller pins, 165 has 3 large pins and 6 smaller pins with one of the smaller pins inside the main circle.

The 160 also has two large resistors mounted just behind the connector as well as a plastic bit with fins mounted to the transom just next to the blower that has 3 wires going into the harness behind the engine. The wiring diagram for the Sea ray (many thanks to an original owner who didn't throw anything away) shows this as the transistor voltage regulator.

Seems the best thing is going to be moving the harness from the 160 over to the new motor. Seems easier if practical to move the connector...


Any cautions, ideas or experiences appreciated before I move forward...

Thanks,

Steven

 

[Fishermark]

Re: Engine swap electrical questions

I don't know either engine specifically well enough to know the exact answer... but... if the new engine has an alternator with a built in regulator, (likely), then you do not need the external voltage regulator. I would suggest using the harness that came with the new, good engine and finding a matching boat wiring harness on ebay or somewhere similar. You can usually pick one up for very little coin.

 

[Steven D]

Re: Engine swap electrical questions

I've got the original connector from the donor boat and may well splice it into the Sea Ray. Looks pretty straight forward if the wiring diagram in manual #3 is correct for this engine (should be...).

Anyone who's done this or knows of any "gotchas" please chime in.

Thanks,

Steven

 

[jtybt]

Re: Engine swap electrical questions

Not sure how applicable but I went thru a similar situation when I converted a 1978 points type ignition to a thunderbolt IV electronic ignition. and changed the alternator from a mando to single wire delco.

The main connector was different but the wiring code was the same. Basically, I had to cut one prong off and connect(externally) the orange wire. I also had to tape off 2 or 3 of the alt wires and a few of the sending unit wires that my engine didn't have. It's been like that about 11-12 years and no problem. I recently swapped the TB IV ignition to the delco EST ignition but see no difference in performance.

 

[Steven D]

Re: Engine swap electrical questions

Did the swap over of the plug from the donor boat harness this morning and all seems well. Boat turns over and has fire, can't tell about the gauge functions until I install the manifold and actually see things running which won't happen until the new flapper valve arrives.

Again thanks to all for the assistance...

Steven