Converting always on cigarette lighter to switched power

E

Electrocuted

New Member
So my car's cigarette lighter is always powered even when the car is switched off. I am attempting to make it switched so that the power is only on when the key is turned to accessory. I made a basic drawing of the fuses I want to connect.

I have seen a few ways people are doing this. One way is by using an add-a-circuit fuse tap



where the pigtail end goes to fuse 1B and the plastic part (where the 2 fuses are on top of each other) goes to fuse 2 with the left blade going to 2B. It looks a little something like this

I don't really understand why it's done this way when in my mind, I should get an inline fuse holder

and just connect one end of it to 1B and the other end to 2A. Would that work safely? I would leave fuse 1A and 2B empty and my cigarette lighter become switched on when the key is turned to accessory. Not sure why I need 2 fuses with the add-a-circuit when all I want is switched power.
 
Sort by date Sort by votes
The add-a-circuit fuse holders have two fuses so that one replaces the original fuse and the other provides fusing for the additional circuit. You should still keep fuse 1 with the same value as before to run the item you have called “some device”. You also should have a second fuse to power the cigar lighter socket in case it gets shorted.

One thing you need to check is that 1B does turn off when the ignition turns off. On some cars, some circuits that turn off when the ignition is turned off leave the fuse live, and if that circuit is arranged in that way you will need a different approach.

What you want:-
Battery -> switch controlled by ignition -> fuse -> “some device”

What you don’t want:-
Battery-> fuse -> switch controlled by ignition -> “some device”
 
Upvote 1 Downvote
Thanks, I'll have to double check 1B if it's off but I'm pretty sure it is. If not, I'll look for another location.

I think I messed up when I said the pigtail end should go into 1B when it should go to 1A. I drew up this updated diagram. I'm going to crimp on a spade/blade connector to the end of the pigtail. Does it look right?

 
Upvote 0 Downvote
I think I'm starting to understand this whole add-a-circuit fuse tap. What led me to originally ask the question about this whole install is that I saw some empty fuses in my fuse box and didn't quite understand this fuse tap with empty fuses.

If fuse 1 in my original drawing was empty but still had switched power and "some device" is just to indicate the device side of the fuse, would it be ok if I just use an inline fuse holder and connected one side of that fuse holder to 1B and the other to 2A? 1A and 2B would be empty.

 
Upvote 0 Downvote
That would work as long as fuse 1 wasn’t fitted originally. Also my warning in post #2 applies.
 
Upvote 1 Downvote
You must log in or register to reply here.

Similar threads

C
  • Question
Multiple car cigarette lighter males to 1 female connecting, wiring options
Replies
2
Views
5K
rjenkinsgb
W
My kids ride on Jeep project
Replies
14
Views
4K
Pommie
P
S
  • Question
No output on car amp
Replies
3
Views
5K
Diver300
D
D
Trying to build a 12v stator
Replies
18
Views
2K
Diver300
D
  • Question
Wire designation on complex coloring schemes (Nissan 2000)
Replies
3
Views
5K
Grossel
Menu
Log in
Register
Cookies are required to use this site. You must accept them to continue using the site. Learn more…