470 wiring harness compatibility.

[juicebronco]

So I blew by 85 170MR which we all know is a 470. I picked up a 83 viking deck boat with a 470 in it for $150 and I'm trying to get it running, to make sure everything is good to go prior to installing it into my boat.

Who ever had worked on this thing in the past should be arrested. The wiring is just a mess, it all appears to be hooked up, but wires have been clipped and twisted back together with extensions, and it's just not pretty. I've gotten it to turn over now, and it fires while the starter is engaged, but as soon as I turn the key to run, it shuts down. The ignition switch had already been replaced, and there is a new coil on it. I also noticed that the kind of redish purpleish wire that comes off the coil and eventualy gets to the carb is getting hot with the key in the run position. So obviously I have some electrical issues.

My thought is to pull the harness off the 85, and put it on the 83. They should be the same correct?

 

[achris]

Sounds like a resistance wire problem....

As long as the 83 engine instrument cluster has a voltmeter and not an ammeter, then the harnesses are plug and pray....

Chris..........

 

[juicebronco]

Thank you, install went smooth. Boat still doesn't start, so I guess it's time to do some more research.

 

[nola mike]

That purple wire is the resistance wire, it's supposed to get hot. With the key in the start position you get a full 12v from the slave solenoid. The resistance wire should give you 9v or so in the run position. Your symptoms sound like that isn't happening, though if the resistance wire is getting warm that indicates that you're probably getting voltage.

 

[stonyloam]

When the starter is turning the coil + is getting voltage from the slave solenoid, when the key goes back to "run" it is supposed to get it from the purple resistance wire. Try running a jumper directly from the battery to the coil +. If it keeps running look for a problem between the ignition switch and the resistance wire. The resistance of the resistance wire should be about 1.8 to 2.0 Ohms.

 

[juicebronco]

Thanks for the help, I actually started a new thread with more details of this exact issue. I figured it would help future searchers.