Hot wire for D.U.I. distributor -where to connect?

Ordered a DUI distributor, but am not sure where to connect a hot wire to power it. Boat is a 1990 Ski Nautique with PCM Ford 351W.

I know it needs to be connected to a terminal that's only hot when the key is in the ON position. Would that be the wired end of the (bypassed) ballast resistor or does someone have a better idea?

Thanks

The manufacturer recommends a separate hot wire.

SNobsessed wrote: Separate from what?  Won't the purple wire only be feeding distributor & choke?  Should be able to handle that.

I use a relay to power the choke and the alternator energize.
This frees up the purple wire to juice only the msd energize and the relay
You could do something similar and not have to run another wire from dash

Don't relay the ignition because during cranking the voltage drop won't permit the relay to apply power to ignition and it will sometimes fire only when you stop cranking , if you are lucky

GottaSki wrote: If electricity isn't your bag, I can understand I'm not able to draw something out for a while, but your relay is switching in 12v constant at the engine to the choke and alt.

No hurry. The DUI distributor isn't scheduled for delivery until mid-October.

8122pbrainard wrote: GottaSki wrote: Don't relay the ignition because during cranking the voltage drop won't permit the relay to apply power "<span style="color: rgb17, 17, 17; font-family: Roboto, sans-serif; font-size: 18px;">Typical 12V automotive relays have a "pull in" voltage around </span><span style="font-weight: 700; color: rgb17, 17, 17; font-family: Roboto, sans-serif; font-size: 18px;">8V</span><span style="color: rgb17, 17, 17; font-family: Roboto, sans-serif; font-size: 18px;"> and a drop out voltage somewhat lower."</span> <span style="color: rgb17, 17, 17; font-family: Roboto, sans-serif; font-size: 18px;"> </span> <span style="color: rgb17, 17, 17; font-family: Roboto, sans-serif; font-size: 18px;">If there's less than 8 volts during cranking then I'd say there are other problems with the electrical. </span>

Real world conditions say someday a labored start occurs and the relay won't see enough voltage to close then one trying to start with the ignition off. I stand by ignition must not be relayed

uncle-buck wrote: Ordered a DUI distributor, but am not sure where to connect a hot wire to power it. Boat is a 1990 Ski Nautique with PCM Ford 351W. I know it needs to be connected to a terminal that's only hot when the key is in the ON position. Would that be the wired end of the (bypassed) ballast resistor or does someone have a better idea? Thanks

On my '92 I ran the positive wire for my DUI directly from the 50amp breaker on the engine through two relays.  I used the old ignition wire as the relay control voltage.  It comes directly from the ignition key and is also connected to the "I" terminal through the old fusible link exactly as came originally.  I didn't add any new wires to the dash.   Not sure if a '90 has the link or not although I doubt you need it.  Ran it for the last two summers with zero problems.  This was a Protec conversion so the wiring is a little different than a '90.  The Protec system has two fault sensors which a '90 doesn't have.  I wired the old over temp fault sensor to the second relay so the engine shuts off if it overheats.  The third relay in the picture is just a spare.

So, converting a PCM engine to a DUI and stacking the purple wire, the orange wire to the starter, and the wire to the DUI on one end of the no longer needed resistor is wrong as there might be too much voltage drop to the DUI?

Wire colors are as I posted, but there is no choke wire.  The orange wire to the starter is actually to the solenoid, so it  must be to the I terminal.  I added an hour meter to the stack, so hopefully it won't cause a problem. Guess I should put a meter on it while it's running.

On my 1994, the PCM factory wiring used the starter switch solenoid “I” terminal as the ECM power feed for ProTec. This was a key on/start switched power source.  When I removed ProTec, I used the “I” terminal for 12V power feed to the new dizzy.  It worked very well for my DUI conversion.  I did run a 20 amp in-line breaker...just for fun.