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Rewiring Headlights To Only Work With Ignition On

  • Thread starter Thread starter TheUser
  • Start date Start date Jun 3, 2007
T

TheUser

Active Member
Jul 25, 2003
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Springfield, MO
Jun 3, 2007
#1
  • Jun 3, 2007
  • #1
I want to rewire my headlights to only be able to come on when the ignition is on whether the switch is on or not. The reason I want to do this is because I have a very bad habit of leaving my headlights on, which obviously drains the battery. I don't remember if stock fox's had the chime when the headlights were left on or not, but mine doesn't work. Either way, this is what I want to do.

I've searched a bit on Stangnet and came across the thread about the foglight fix. Jrichker posted a diagram, which is essentially what I want to do with my headlights. I edited the diagram and it is presented below for a few of you guys to look over for any errors or misunderstandings. It seems fairly straight forward to me. I'd have to basically do the same thing to the high and low beams, which would require 2 relays.

I suppose the SPST 30Amp Relay would be ok? I realize the headlights should only be a 10amp load (55watts each IIRC x2 = 110/12v=9.17amps.

Also, can anyone suggest a good location to place the relay for my application? Without looking, I'm not real sure how the headlight wiring is routed.

Here's the diagram:
 

Aryan15

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Sep 22, 2003
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Jun 3, 2007
#2
  • Jun 3, 2007
  • #2
I would probably mount the relays on the fender or in the dash somewhere. If it were one relay, I would say where the headlight switch is, but I don't know if two of three would fit in there. I used a fuel pump relay for the headlights on my tempo because I don't like the blade connections on those radioshack relays and it has a bracket for mounting purposes.
 

jrichker

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#3
  • Jun 3, 2007
  • #3
TheUser said:
I want to rewire my headlights to only be able to come on when the ignition is on whether the switch is on or not. The reason I want to do this is because I have a very bad habit of leaving my headlights on, which obviously drains the battery. I don't remember if stock fox's had the chime when the headlights were left on or not, but mine doesn't work. Either way, this is what I want to do.

I've searched a bit on Stangnet and came across the thread about the foglight fix. Jrichker posted a diagram, which is essentially what I want to do with my headlights. I edited the diagram and it is presented below for a few of you guys to look over for any errors or misunderstandings. It seems fairly straight forward to me. I'd have to basically do the same thing to the high and low beams, which would require 2 relays.

I suppose the SPST 30Amp Relay would be ok? I realize the headlights should only be a 10amp load (55watts each IIRC x2 = 110/12v=9.17amps.

Also, can anyone suggest a good location to place the relay for my application? Without looking, I'm not real sure how the headlight wiring is routed.

Here's the diagram:
Click to expand...

Eliminate the fuse, since the headlight power is already fused at the fuse box (fuse #4).
Change the power source for the relay coil (#86) to connect to the red/ green wire that connects to the ignition coil and you are all set. The red/green wire can also be tapped at the ignition switch if it is easier for you to get to.
 
T

TheUser

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Jul 25, 2003
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Springfield, MO
Jun 3, 2007
#4
  • Jun 3, 2007
  • #4
Thanks guys

Jrichker, I suppose in my haste I typo'd...I meant 12v from ignition source...nice find I'll prob. pull it from the ignition switch as you suggest, but we'll see.

Hmm...Fuse #9 for the AC/Heater Blower Motor should only have power when the ignition is on, correct? Could I use one of those piggyback (forgot the name) type of connectors to pull power from there for the relay coil power side?
 

HISSIN50

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#5
  • Jun 3, 2007
  • #5
TheUser said:
Hmm...Fuse #9 for the AC/Heater Blower Motor should only have power when the ignition is on, correct? Could I use one of those piggyback (forgot the name) type of connectors to pull power from there for the relay coil power side?
Click to expand...

It's not super optimal for a permanently tractable connection, but should work well for years. If you like that location and source, if you ever have the fusebox out, you can solder into the same wire but at the rear of the box. This will clean things up and be a stronger connection.

Good luck James.
 
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