12v with key on

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cdwmotorsports

cdwmotorsports

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I am wanting to wire some 12v keyed accessories in my Demon. What I would like to do is add a blue sea fuse box and run the 12v keyed source to it and then utilize the power through the new fuse box.

Is there any reason I can’t do this?
Where would you draw this keyed power from?
Is there a better way to do this? Relay or otherwise?

I am for sure adding Autometer gauge wiring and the contour fan setup needs to be powered from here too.

The fuse block will have at least 6 spots. I have a second one of these wired hot to starter relay for ignition, fuel pump, water pump and other items I want to be able to run without key on if needed.
 
Just added 2 fuse blocks in mine on switched and the other unswitched. I added a relay to supply power to the switched block. I ran a 10 gauge wire from the starter relay to the unswitched block and then used the feed from the unswitched block to feed the relay for the switched block. I mounted everything to a plate that mounts under the dash. I also mounted the regulator and Mallory ignition box to it as well
IMG_20180113_232216624.jpg
IMG_20180113_232403354.jpg
 
I would use a relay. Your answers are in the service manuals. You can download some years from MyMopar. Some of the manuals there came from the guys on HERE


There are only two 12V sources switched by the key, that is "ignition run" (ign1) and the switched accessory wire going to the acc buss in the fuse panel. The fuse panel has THREE busses.....

1......"hot" on all the time for such as brake lights
2......."ACC" switched by the key
3.......The "trick" fuse for the instrument lamps. This fuse is powered FROM the instrument dimmer control, which is powered off the tail lamp circuit. That is identified by the fuse at one end of the box, with a "bunch" of orange wires. So stay away from that

For your added panel, what sorts of things and what kind of amperage do you expect to draw? If you have a stock ammeter, "it might" be too much to pull off that. One place is to power the relay contacts off the starter relay stud. You will have to "make" a path into the interior. I would put a "master" fuse/ breaker as close to the battery connection as you can
 
If you pull power from the starter relay, make sure you have a wire around in place.

Chad,

If you don't have some accessories in the car, radio for example, use the power wire from there as a 12v keyed source. If this is for switching the fan controller, you should be fine as it's a low load trigger wire.
 
67Dart273, I don’t have an FSM, mine isn’t on mymopar and no one here seems to have a digital copy. Thanks though.

Thanks Rob. I don’t have a radio so that should work if I can locate those wires.
 
Key on 12v also goes to the flashers, that's probably the easiest source to access !
 
Because I now have everything under the. dash (to clean up the engine compartment) I now run a 10 gauge wire from the starter lug to a 30 amp circuit breaker mounted down low near the frame but easily reachable and then on through a rubber grommet to the starter relay lug. It is important to protect the feed wire with a circuit breaker or at least a fuseable link.
 
cdwmotorsports said:
67Dart273, I don’t have an FSM, mine isn’t on mymopar and no one here seems to have a digital copy. Thanks though.

Thanks Rob. I don’t have a radio so that should work if I can locate those wires.
Click to expand...

What year is your car?
 
67Dart273 said:
You didn't look very hard, LOL, there is a 72 manual at MyMopar and it came from AbodyJoe right here
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Crackedback has a good suggestion....to key a relay the radio will work. Only, it will be on in accessory, as well
 
superchargeddrt said:
Because I now have everything under the. dash (to clean up the engine compartment) I now run a 10 gauge wire from the starter lug to a 30 amp circuit breaker mounted down low near the frame but easily reachable and then on through a rubber grommet to the starter relay lug. It is important to protect the feed wire with a circuit breaker or at least a fuseable link.
Click to expand...

Good approach. Sounds as though you don't have the ammeter in place either which is an issue with pulling power at factory starter relay location.

Nice panel and good for powering accessories, etc. Troubleshooting is so much easier when everything is in one spot!
 
Yeah I got tired of the wiring rats nest under my and engine compartment. Yes I have made the ammeter modification. By the way, running your regulator power from the relay eliminates the flickering headlight syndrome.
 
crackedback said:
Good approach. Sounds as though you don't have the ammeter in place either which is an issue with pulling power at factory starter relay location.

Nice panel and good for powering accessories, etc. Troubleshooting is so much easier when everything is in one spot!
Click to expand...
Yeah I got tired of the wiring rats nest under my and engine compartment. Yes I have made the ammeter modification. By the way, running your regulator power from the relay eliminates the flickering headlight syndrome.
 
cdwmotorsports said:
View attachment 1715147167 Can anyone tell me what my fuse block is supposed to be labeled? I can make out turn signals and that’s about it
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Sure......in the 72 shop manual ^^just above this post^^ page 8-127 is a chart showing fuse values and what that fuse serves (Valiant)

Then go to 8-151, the inst. panel diagram the fuse panel is labeled. Some years cars have a pictorial of the fuse block, I don't thing 72 does

fuse.jpg
 
These are quite large pdf's You need to scrouge up a "real computer." Either that or you might bounce around ebay and see if you can find a reprint/ CD, or even old original for sale.

Frankly I cannot imagine attempting to view these on a tiny screen
 
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