need underhood 12+ switched power

Electronic systems, stereo and Holden iQ, wiring, it all goes here....
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xcidmigs
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need underhood 12+ switched power

Post by xcidmigs »

I'm adding a aftermarket wiring harness for lights, trying to find an underhood hookup for 12+ when car is running only? Not seeing anything like that in the underhood fuse box what can i tap into?
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mercialogo
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Re: need underhood 12+ switched power

Post by mercialogo »

you could use part of the in car ( upfitter ) wiring. There are 2 separate harnesses under the passenger side dash. One has a plug with 2 20 amp Light Green wire power wires. That one also has a power\accessory wire ( brown ). If you connect it to 1 of the 4 leads that go under the hood ( other power connector Brown, Gray, Lt Green, Dark Green ) then you would have your switched power under the hood to use. oh, and those 4 leads are taped and terminated to one of the Air conditioner hoses on the passenger side engine bay on top. What kind of lights are you installing? I ask because that brown power\accessory wire would not handle anything with high amps.
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xcidmigs
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Re: need underhood 12+ switched power

Post by xcidmigs »

its a standard 2 light stand alone harness that uses a relay so the big power draw goes straight to the battery the switched connections are low amps to "turn on" the relay.

I found that these under passenger side harnesses do have several wires that come out on the underhood area there is a 4 connector flat harness on the passenger side fender area that has a empty connector plugged into it. any of the 4 wires can be used for switches etc that are mounted inside the cab to control something underhood. I'm using the single brown wire to get a positive 12v when the car is running only and I got power to it front inside the car by using a small jumper wire from the orange colored wire to the brown. its the lower of the 2 plugs which also contains the green wire for the factory wig wag module turn on.
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I would like to find a better solution to inserting wires into this plug if anyone has a suggestion of a terminal thats commonly availiable at part stores that can be crimped on I'd like to hear it?
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smwalker
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Re: need underhood 12+ switched power

Post by smwalker »

XD I think you are tapped into the vehicle speed sensor wire there, the orange one. From the description of the circuit it states "Output voltage varies with speed from a minimum of 0.5 volts at 100 RPM to more than 100 volts at 8,000 RPM. "

From the listing here (although I think it is not accurate because it says there should be 16 cavities and I only see 12 on that plug) I think the better choice would be the pink and dark blue stripe for a 12 volt ignition source.

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Steve Walker
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xcidmigs
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Re: need underhood 12+ switched power

Post by xcidmigs »

i got a steady 13.4 volts on that oranger terminal with ignition on only.... not sure on your diagram I have made my fog light circuit work using just as described already.
smwalker
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Re: need underhood 12+ switched power

Post by smwalker »

xcidmigs wrote:i got a steady 13.4 volts on that oranger terminal with ignition on only.... not sure on your diagram I have made my fog light circuit work using just as described already.
Oh OK they must have switched it at the other connector to 12 Volt ignition.
Steve Walker
Azusa, CA
'11 PPV 9C3 Huron White
xcidmigs
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Joined: Fri Feb 13, 2015 8:12 pm
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Re: need underhood 12+ switched power

Post by xcidmigs »

Nope you were correct I mis read the voltage meter as telling the whole story, the orange wire isn't giving true ignition switched 12+, the other pink/blue one is... and I just used a vampire tap to connect that to the grey wire which is one of the 4 wires not used that goes from the passenger compartment to the engine bay. No need to make holes or mess with the under hood fuse box.
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