Need 12 Volt To Install Fuse Box I Engine Compartment

DocUsn

New Member
Jan 9, 2015
15
0
1
I'm trying to run 12 volts to an auxillary fuse block in the engine compartment. where can I hook into get 12 volts. I'm doing this so I can access future accessories that need power. I'm a newbie need help! I have 1972 Mustang covertible with 351 cleveland. Do I hook in just after ignition switch?
Is there a guide I can get? I'm also installing a procompt distributor that requires 12 volts. Any one with ideas? Thanks in advance! from DocUsn
 
  • Sponsors (?)


I'm trying to run 12 volts to an auxillary fuse block in the engine compartment. where can I hook into get 12 volts. I'm doing this so I can access future accessories that need power. I'm a newbie need help! I have 1972 Mustang covertible with 351 cleveland. Do I hook in just after ignition switch?
Is there a guide I can get? I'm also installing a procompt distributor that requires 12 volts. Any one with ideas? Thanks in advance! from DocUsn
Horse sence If I hook the new power source into the positive side of the selinoide can I hook up my new procomp distributor that needs 12 volts into new power source and work okay? I'm a newbie
thanks for your patience!
 
Dont know what i was thinking ,the 12 volt needs to come from the key switch or the 12 volt to the dist will be hot all the time
That means I can hook into the red/green or is it pink, just after ignition switch, right? I will use 10 gauge wire for the hook up, any other suggestions that I'm not thinking of?
 
For the dist. wire you will not need a wire as big as 10 gauge . You will need the wire on the key switch that has power when the key is in on position and the start position but nothing in the off position. I don't think the wire is pink right at the key switch but farther in the loom it is pink .
 
2012-04-30_112741_121212.jpg
I can tell you what I did. I used an 80 amp relay wired direct from the battery pos. This relay is triggered off my ignition switch. That relay powers my aux fuse box mounted in my engine bay. The fuse box has all the blades for power hookups and ground hookups and slots for each blade type fuse for individual circuits. I have my fuel pump, coil, rad fan, and fog lights hooked to it. Makes it real easy to troubleshoot and change a fuse. I'll see if I can post a pic later.
 
Last edited:
  • Like
Reactions: 1 user
2012-04-30_112741_121212.jpg
I can tell you what I did. I used an 80 amp relay wired direct from the battery pos. This relay is triggered off my ignition switch. That relay powers my aux fuse box mounted in my engine bay. The fuse box has all the blades for power hookups and ground hookups and slots for each blade type fuse for individual circuits. I have my fuel pump, coil, rad fan, and fog lights hooked to it. Makes it real easy to troubleshoot and change a fuse. I'll see if I can post a pic later.
Tos: thank you so much, you taught a valuable lesson to me. You've help me solve a pressing electrical problem!
My Mustang is a 1972 Mustang convertible with a 351 cleveland 4 barrel edlebrock 1406 carb. I switched it to electronic ignition which was a pain. I need to convert to disc brakes, give a Ruby red #2 paint thats on the new Ford
PU, redo my seats, put new circuit board behind the dash gauges, new turn signals, so I've got a lot to do but I have the time and I am enjoying the car greatly. So once again thank you for time you spent showing me how to solve future electrical needs under the hood.
 
No problem, That's what this board is for, we all help one another.
Just to add to my post, make sure you calculate the amperage you will be pulling by adding up all the components you're going to plug into your fuse box cause that relay will be the passage way for those components. I would do 80 amps as a minimum so you have room to add items later.
 
No problem, That's what this board is for, we all help one another.
Just to add to my post, make sure you calculate the amperage you will be pulling by adding up all the components you're going to plug into your fuse box cause that relay will be the passage way for those components. I would do 80 amps as a minimum so you have room to add items later.
would 100 amps be good?
 
I actually meant to say 40 amps as a minimum, I used 80 myself but will never load that much amperage all at once myself. Also keep in mind that if you have a stock alternator you might want to get one that puts out more amperage cause you don't want to overload the alternator. Stock alternators only put out between 35 and 55 amps. I upgraded to a 120 amp one i believe. it depends on you and all you want to hook up to it. Add up everything you have plans for and decide what all will be operating at the same time and then get a big enough relay to handle a little more than that. If your needs add up to lets say 38 amps then you don't want to only put a 40 amp relay in, more like 60 in this example.
Some electric radiator fans take approx. 30 amps to run but 100 amps would probly be over doing it in most cases unless your adding heavy duty stereo equipment too?
 
Just another option. I installed a Painless Performance 7 fuse relay/auxiliary fuse box in my '67 and would highly recommend it. One line to battery, one tapped off a fuse in the main fuse block, and boom, 3 constant hot circuits, 4 switched circuits all for 12V. Nice and neat way to wire in electric choke, electric fans and an aftermarket stereo.

CirKit Boss Auxiliary Fuse Block/7 Circuits/WeatherproofDetails | Painless Performance
 
I actually meant to say 40 amps as a minimum, I used 80 myself but will never load that much amperage all at once myself. Also keep in mind that if you have a stock alternator you might want to get one that puts out more amperage cause you don't want to overload the alternator. Stock alternators only put out between 35 and 55 amps. I upgraded to a 120 amp one i believe. it depends on you and all you want to hook up to it. Add up everything you have plans for and decide what all will be operating at the same time and then get a big enough relay to handle a little more than that. If your needs add up to lets say 38 amps then you don't want to only put a 40 amp relay in, more like 60 in this example.
Some electric radiator fans take approx. 30 amps to run but 100 amps would probly be over doing it in most cases unless your adding heavy duty stereo equipment too?
tons thank you once again for great advice. Can you tell me what brand of alternator you used?I need one that i can use V belt pulley. Is there a model year that has this alternator? Can use the advice.
 
I ordered mine thru one of the mustang websites, Probly CJponyparts or NPD and got it in chrome. You should be able to order a higher amp alternator for your car and it should come with the v-belt pully.
Here is one for your car from Summit Racing.
http://www.summitracing.com/parts/tff-7069fbull/overview/year/1972/make/ford/model/mustang
Im not suggesting this particular one just showing an example cause they have several to choose from. They have very quick shipping and the best return policy where cjpony has always givin me flack about returns even if its their screw up. Summit will pay return shipping even if you screwed up. I know that from experience.
 
sorry for the answer delay. I've ordered a 140 amp alternator this should meet my future electrical needs.
I'm also going to put inlne manuel 140 amp braker between alternator and battery to keep system from
overload. My personal thanks for the great ideas everyone has given me!!!!!!!!!
 
When I hooked up my one wire alternator, how do i get my alt dash lamp to work? Also I got rid of the old regulator harness and had 2 wires left , red carb choke wire, and a green\red wire that was in the harness plug in on the external regulator that i removed. Where does the red/green wire go? Thank you for your help in advance! The info received from all you guys was perfect!
 
That green/red wire I believe was your charge indicator wire. Im not exactly sure how or if you can use that because it was on its own individual regulated circuit. it was activated by the regulator when the alternator showed low charge output. There is a series of relays/switches inside the original regulator that do different things and one of those swithes turns that light on under low or no charge. I don't think it will work properly now unless you were to hook up some sort of relay to activate it the same way. My suggestion now would be to install a gauge.

As for your choke wire hook it to any 12v switched power source - Power source that turns on and off with the ignition switch.
 
Last edited: