A diode it is a great solution
Is it a diode that's needed?
Thread Starter
Racer
Joined: Sep 2007
Posts: 265
Likes: 17
From: City of Kawartha Lakes, Ontario
Is it a diode that's needed?
I'm trying to supply power to some lights from more than one source.
One of the sources is from the factory fuse box. I'd like to protect the factory wiring from any problems that power being supplied to the same wire when it's not supposed to be might cause. ..... Confused?
I believe that a diode wired into both of the supplies would be the solution, but I can't find out what diode is needed. Then to add to the confusion, it seems like I might need to add a resistor to protect the diode?
Any help would be appreciated.
Thanks,
Brad
One of the sources is from the factory fuse box. I'd like to protect the factory wiring from any problems that power being supplied to the same wire when it's not supposed to be might cause. ..... Confused?
I believe that a diode wired into both of the supplies would be the solution, but I can't find out what diode is needed. Then to add to the confusion, it seems like I might need to add a resistor to protect the diode?
Any help would be appreciated.
Thanks,
Brad
Le Mans Master
Joined: Nov 2004
Posts: 8,718
Likes: 20
From: Dyer IN
Cruise-In IX Veteran
How much current will lights draw. A. 5 amp diode will be more then enough I would think but I don't know exactly what you are powering. No need for a resistor a diode will do the trick.
Your local radio shack should stock these I use them for diode isolating parking lights in alarm installs.
http://www.radioshack.com/product/in...ductId=2062591
Your local radio shack should stock these I use them for diode isolating parking lights in alarm installs.
http://www.radioshack.com/product/in...ductId=2062591
Thread Starter
Racer
Joined: Sep 2007
Posts: 265
Likes: 17
From: City of Kawartha Lakes, Ontario
Thanks pentavolvo!
I'd like to hook up a switch for my fog lights (HID) that would allow me to power them anytime, but I don't want to loose them coming on when I lock the car or unlock the car. I'd also like to keep them functioning exactly as stock when the switch is off.
It'd be easy just to have them switched only, but I like the stock functions of them.
I'll head to the local radio shack and check them out. Unfortunately our local radio shack has salespeople who know absolutely nothing about electronics, so they where no help.
Thanks,
Brad
I'd like to hook up a switch for my fog lights (HID) that would allow me to power them anytime, but I don't want to loose them coming on when I lock the car or unlock the car. I'd also like to keep them functioning exactly as stock when the switch is off.
It'd be easy just to have them switched only, but I like the stock functions of them.
I'll head to the local radio shack and check them out. Unfortunately our local radio shack has salespeople who know absolutely nothing about electronics, so they where no help.
Thanks,
Brad
Racer
Joined: Oct 2008
Posts: 467
Likes: 102
From: Torrance CA
A relay could be used to switch the fog light's power source.
You could wire it so:
The relay at rest will send power your fog lights normally.
energized the relay with a switch .... to send power to your fog lights when you want.
The lights will be isolated and a relay is capable of handling enough amps to power your fog lights.
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
I wrote up this DIY post a while back that shows how to have the fogs come on any time the brights are on.
For your project, instead of using J4 (brights) as the power supply you can just use B+ via your switch. Connect a wire to any B+ source, install an inline fuse as close to B+ as you can (2 amps is plenty), continue the wire to your switch, run the other switch terminal wire to fuse box pin A4. You can install a diode in the new wire to make sure current only flows from B+ to fog relay, but if you did it this way I believe you'd be fine without one.
Doing it with the control power will make them come on just like normal, or whenever you turned on the switch, and the new wire would only draw 0.125 amps when the switch was on so you could use a very small gauge wire without any issues.
Schematics: FOG LIGHTS & HEADLIGHTS
For your project, instead of using J4 (brights) as the power supply you can just use B+ via your switch. Connect a wire to any B+ source, install an inline fuse as close to B+ as you can (2 amps is plenty), continue the wire to your switch, run the other switch terminal wire to fuse box pin A4. You can install a diode in the new wire to make sure current only flows from B+ to fog relay, but if you did it this way I believe you'd be fine without one.
Doing it with the control power will make them come on just like normal, or whenever you turned on the switch, and the new wire would only draw 0.125 amps when the switch was on so you could use a very small gauge wire without any issues.
Schematics: FOG LIGHTS & HEADLIGHTS
Race Director
Joined: Oct 2007
Posts: 11,367
Likes: 211
From: Edgewood Washington
St. Jude Donor '11-'12-'13-'14-'15
Here's some more circuit description/clarification/etc. citing markcz's post.
I haven't done this mod yet, but it's definitely on my radar, especially if /when I retire to the waterfront cabin in the sticks.
6 HID's lighting the way would be just what my aging eyes may need.
http://forums.corvetteforum.com/c6-c...igh-beams.html
I haven't done this mod yet, but it's definitely on my radar, especially if /when I retire to the waterfront cabin in the sticks.
6 HID's lighting the way would be just what my aging eyes may need.
http://forums.corvetteforum.com/c6-c...igh-beams.html
Thread Starter
Racer
Joined: Sep 2007
Posts: 265
Likes: 17
From: City of Kawartha Lakes, Ontario
Thanks for all the help guys!
I am looking at both the diode and the relay way.
Just to clarify. Any B+ in the fuse box means any direct battery connection? If this is the case, I can substitute any ACC source for the B+ source correct?
Could I use the footwell fuse panel as a source to shorten the wiring required? That would leave only one wire going out to the under hood fuse box to trigger the light circuit?
Thanks again,
Brad
I am looking at both the diode and the relay way.
Just to clarify. Any B+ in the fuse box means any direct battery connection? If this is the case, I can substitute any ACC source for the B+ source correct?
Could I use the footwell fuse panel as a source to shorten the wiring required? That would leave only one wire going out to the under hood fuse box to trigger the light circuit?
Thanks again,
Brad
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Thread Starter
Racer
Joined: Sep 2007
Posts: 265
Likes: 17
From: City of Kawartha Lakes, Ontario
Shouldn't attempt wiring after finishing night shifts!
Tech Contributor
Joined: May 2003
Posts: 7,035
Likes: 134
From: North Augusta, SC
The battery itself, any fuse box B+ post, or any terminal on a fuse box that has +12v on it (constant or in ACC) can be used as the "B+" source 
If you use a switched source (only on if car is in ACC or run) then I'd use a diode in the new wire, just to make sure the BCM fog light output doesn't somehow end up powering the ACC line you tap. If you use a terminal that's straight off the battery you probably don't need the diode.
If you use a switched source (only on if car is in ACC or run) then I'd use a diode in the new wire, just to make sure the BCM fog light output doesn't somehow end up powering the ACC line you tap. If you use a terminal that's straight off the battery you probably don't need the diode.
Thread Starter
Racer
Joined: Sep 2007
Posts: 265
Likes: 17
From: City of Kawartha Lakes, Ontario
Thanks for the help guys.
I ended up using the HVAC circuit in the passenger footwell as my supply. The lights work exactly as I wanted them to.
They are not connected to ACC power. When the new switch is on the fogs are on only when the engine is running. The fogs still turn on whenever they would stock, no matter what position the new switch is in. Plus I can have them on whenever I want by flipping the switch.
I went the diode route. Not 100% sure if I even needed the diode, but I'd rather be safe.
Later,
Brad
I ended up using the HVAC circuit in the passenger footwell as my supply. The lights work exactly as I wanted them to.
They are not connected to ACC power. When the new switch is on the fogs are on only when the engine is running. The fogs still turn on whenever they would stock, no matter what position the new switch is in. Plus I can have them on whenever I want by flipping the switch.
I went the diode route. Not 100% sure if I even needed the diode, but I'd rather be safe.
Later,
Brad