guno89

This isn't for my Corvette, this forum is the best so i figured I would post here. On my 2003 mustang (station car) if I don't drive it for 3-4 days the battery dies. I hooked up my multimeter and starting pulling fuses and the amps dropped. The fuse is a 5 amp fuse called GEM (general electric module) I just pulled it to solve the problem since I sometimes go 2 week s w/o driving the car. Problem is that fuse controls the wipers, interior lights and one touch drivers side window.

I want to wire a switch to that fuse so I can turn it off and on.

I really don't know much about wiring and electric. I got a switch at radioshack it has 3 prongs I assume they are for voltage item power. Best part was somehow it was on clearance and cost me 14 cents. I had a bunch of 12v wire I spliced it wrapped it around the fuse put the fuse in box then I grounded it to some metal. The switch lights up when switched on but it doesn't kill the fuse.

My question is what am I missing or is the way I went about this is completely wrong. I was wondering if I wired the the middle prong to the fuse would that make any difference?

Proff

I have one of these on all of my vehicles ('09 C6, '67 Shelby, & streetrod). It kills the current when it drops below 12 volt. When I hit the remote, the battery reconnects and the car has enough juice to start. Works like a charm!

http://www.summitracing.com/search/p...battery-brains

bobeast

The switch needs to be wired in a series with the fuse. From your description, it sounds like you tried to wire it in parallel, which won't do anything.

Also, with a three pin switch (SPDT) you will only be using 2 pins. The middle, and one end.

Think of the current like water going through a hose. It will go from one side of where fuse normally plugs in -> middle prong of switch -> through switch to one end prong -> one side of fuse -> through fuse and out to remaining terminal where fuse normally plugs in.

guno89

I did a little reading on series vs parallel, ( I know nothing about wiring)

Now my idea is

1) find the wire from the harness going to that fuse cut it
2) run a wire from the tail of wire from the fuse box to the switch
3) run a wire from the wiring harness to the switch
4) ***I assume I don't need to ground it as the harness is grounded?**

In theory this should kill the power, does this sound like it would work?

bobeast

Sounds like you've got the idea. Yeah. That would work.

However there is a way where you can avoid cutting into the harness. The idea is to find a couple of small spade lugs (about the size of the lugs on a fuse). Solder or crimp a wire onto each. Plug them into the fuse location (one for each leg) and then wire in a switch in series with a fuse. The pattern is lug1->switch - switch->fuse - fuse to lug2 and then plug the two lugs into where the legs of the fuse used to go, thus completing the loop.

Of course you can always by one of several kits that do all this work for you. I went with the exhaust commander from Sunset Orange Creations. It allows me to program one of my visor buttons to toggle the exhaust baffles. This should work for the mustang as long as it has the HomeLink feature. If not, then you order the one that uses a key fob to do the same.

guno89

That would be way better I really don't want to splice the harness.

Below is my diagram does this look correct?




Bobeast thanks for the help on this!

bobeast

Yup the wiring looks correct. For the fuse box lugs, consider using so you can just use some slide-on wiring terminals.

markcz

Since you mentioned that the switch you have lights up, I'm going to guess that the third terminal should be grounded to make the light work. Otherwise, diagram above works for what you want to do.

bobeast

@markcz makes a good point. I didn't realize you were using a lighted switch. With a lighted switch, you need to make sure the the correct switch leg goes to ground. Its usually marked with G , - or a symbol that resembles the signal strength bars you see on a cellphone. When you hook up the other two legs, if the switch stays lit up all the time (on or off), just reverse the connections to those two legs.

guno89

Thanks I was wondering if I needed a ground, the switch in the pic is the switch I got from radio shack it came labeled, the 3rd prong with no wire in the diagram is the ground,

Instead of using a fuse breakout or lugs, I just took the metal prongs out of a blown fuse that I had, they are long enough to remove if needed and to add a wire. I can't wire this up until Thursday, amazingly every store I went to only sells the mini fuses for $11 with a variety of fuses I need two 5 amp's so I ordered 10 off em off ebay for $3

guno89

Thanks all for the help, I hooked up the switch yesterday and now am able to kill the circuit when the car will be sitting for more than 2-3 days at a time. I knew zilch about wiring and circuits before, now I have a basic understanding on how things work.