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1967 - 1972 F-100 & Larger F-Series Trucks Discuss the Bumpsides Ford Truck

DUI wiring?

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Old Aug 18, 2015 | 08:15 AM
  #1  
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DUI wiring?

Is wiring the power to the DUI unit as simple as coming off the ignition switch with a replacement wire for the pink resistor wire?
 
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Old Aug 18, 2015 | 08:48 AM
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I'd love to help but truthfully I have no idea what you are talking about. There is no question others have way more knowledge than me, but I bet you would get more answers if you post a little more information - what you are working on, year, model ,engine, etc...

Just a friendly suggestion.
 
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Old Aug 18, 2015 | 09:01 AM
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I ran mine to the starter solenoid terminal that is only hot when the ignition switch is on. Use a thicker gauge wire like 12 gauge I believe. Only one wire to deal with unless you have a tach then you wire the other terminal up to it too. This is my DUI and I assume you are using the same?

 
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Old Aug 22, 2015 | 02:19 PM
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Originally Posted by DLW-70-F100
I ran mine to the starter solenoid terminal that is only hot when the ignition switch is on. Use a thicker gauge wire like 12 gauge I believe. Only one wire to deal with unless you have a tach then you wire the other terminal up to it too. This is my DUI and I assume you are using the same?
Huh? You better check your voltage at that DUI. On the solenoid the "s" terminal gets power from the ignition switch (in the "start" position) to energize that solenoid. The "I" terminal then sends 12V to a wire connector that has the pink wire and a wire going to the factory coil. This is to give the coil a full 12V to help start the engine. After that the pink wire drops it down to 6-8V to help the points last longer. So the "I" terminal only has a full 12V when the ignition switch is in the "start" position. After that would be 6-8 volts back feeding from the connector I mentioned above.
 
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Old Aug 22, 2015 | 02:36 PM
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Thanks man, I'll check that out. I only ran it there as the instructions from DUI gave that as a place to connect to..


"Where do I connect the hot wire to make sure I get 12 volts to my DUI?
A: Your hot wire for the DUI must be at least 12 gauge and it can be connected to the starter solenoid or a fuse. The solenoid is usually
the easiest place to connect your hot wire to but make sure you use the terminal that is hot only when the key switch is in the start and
run position. Same with using a fuse, just make sure the voltage is present only in the start and run position. In most applications, we do
not recommend using the existing ignition hot wire. It may be too small or a resisted wire thus reducing the voltage. 1974 and later GM
vehicles can use the existing hot wire with the DUI as they were originally set up for HEI distributors."



I may have misread it? None the less. I will check the voltage. The truck runs great though right now.
 
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Old Aug 22, 2015 | 03:21 PM
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You didn't misread it. There may be an ignition terminal on a GM solenoid. I Dunno. Those are prolly universal instructions. If it were me I'd use that wire to trip a relay. 12V from the battery side of the solenoid, through the relay, then over to the DUI.
 
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Old Aug 26, 2015 | 03:17 PM
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That's exactly what I will do. Actually what I was expecting to do until I read the instructions, figured there would be some specific warning for the DUI for a FE...Should have went with my original idea. I'm still going to measure the voltage at the I terminal as the truck runs pretty good. It does have an aftermarket solenoid so I will be sure to at least check it out first. Thanks for the heads up about the I terminal 8 volt deal.
 
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Old Aug 30, 2015 | 01:44 AM
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FYI, I measured the voltage at the solenoid 'I" side, and I get 12 volts constant at idle. rev'd up it drops to 10 volts. I do have an aftermarket solenoid. None the less, I now have a relay supplying the voltage from the battery, which runs a pretty constant at 14.6 volts.


Not sure what happened to the OP here not showing back up to there own thread?
 
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Old Aug 31, 2015 | 05:41 PM
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Originally Posted by DLW-70-F100
FYI, I measured the voltage at the solenoid 'I" side, and I get 12 volts constant at idle. rev'd up it drops to 10 volts. I do have an aftermarket solenoid. None the less, I now have a relay supplying the voltage from the battery, which runs a pretty constant at 14.6 volts.


Not sure what happened to the OP here not showing back up to there own thread?
Glad to hear you now have 14.6. But I'm surprised at the 12 then 10. Did you shorten,replace(alter), or delete the pink resistance wire from the switch?
 
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Old Sep 1, 2015 | 12:48 AM
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Originally Posted by JEFFFAFA
Glad to hear you now have 14.6. But I'm surprised at the 12 then 10. Did you shorten,replace(alter), or delete the pink resistance wire from the switch?
Nope, it's all as it was when I got the truck. I didn't really notice a pink wire, but there is a wire that is attached to the "I" terminal and looks stock, maybe the wire is discolored now. I ran an all new wire (12 Gauge) from the new coil to the "I" terminal when I did the DUI install, which is now on a relay.
 
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