Wiring in a Relay to Ignition Switch

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plumkrazee70

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I wanted to wire in a relay to take the load off the ignition switch, but I am not sure I understand how to wire it, due to the start vs accessories.

I have an EZ wire harness and it is all wired and working fine.

Here is how the ignition switch is wired, how would I introduce a relay?

Mopar -------Ez
Red -------> Ign main power (red)
Yellow ----> Ign Switch start (Purple)
Black -----> Accessories (Orange)
Blue/brown (jumped together) ---> Brown/Pink (jumped together)
 
I wanted to wire in a relay to take the load off the ignition switch, but I am not sure I understand how to wire it, due to the start vs accessories.

I have an EZ wire harness and it is all wired and working fine.

Here is how the ignition switch is wired, how would I introduce a relay?

Mopar -------Ez
Red -------> Ign main power (red)
Yellow ----> Ign Switch start (Purple)
Black -----> Accessories (Orange)
Blue/brown (jumped together) ---> Brown/Pink (jumped together)

You mean for the starter function or the power to everything?
Starter function already has one.
 
Sorry, to power everything.

Then you want the relay to be in the red wire and and the current ignition ON wire to activate the relay.

Give me a few here and I can do a diagram for you and post it here.
Keep in mind it will be a basic diagram.
 
Electrically cut everything fed off the blue/ brown where it enters the engine bay
86....Trigger the relay with the blue / brown. IT IS IMPORTANT with some relays to trigger the 86 and ground the 85 because some/ many/ most contain an internal "spike" diode. Reversing polarity on the coil terminals will create a direct short.......until milliseconds later when the diode explodes

85.....Ground the relay coil or feed it through an "unobtrusive" switch which will make a simple anti--theft device

30....Feed the relay power through a fuse / breaker off the "big stud" on the starter relay

87....Connect the engine bay end of the "electrically cut" blue/ brown ---the load end, and connect that to the relay out contace, the NO or normally open.

mini-automotive-relay-wiring-840x.jpg
 
Last edited:
Sorry, to power everything.

You know, after thinking about this for a minute I realized there is more to it than I originally thought because the circuit that powers everything also powers other wires for other things.
If this ignition switch is a stock type it also has two different circuits for the ignition system requiring both circuits be powered in the "start and run" positions of the key.

Sorry, but I can't even start to imagine what it would take to do that on someones car over the internet.

Oh, good.
Del is going to try it.:D
 
Electrically cut everything fed off the blue/ brown
86....Trigger the relay with the blue / brown. IT IS IMPORTANT with some relays to trigger the 86 and ground the 85 because some/ many/ most contain an internal "spike" diode. Reversing polarity on the coil terminals will create a direct short.......until milliseconds later when the diode explodes

85.....Ground the relay coil or feed it through an "unobtrusive" switch which will make a simple anti--theft device

30....Feed the relay power through a fuse / breaker off the "big stud" on the starter relay

87....Connect the engine bay end of the "electrically cut" blue/ brown ---the load end, and connect that to the relay out contace, the NO or normally open.

mini-automotive-relay-wiring-840x.jpg

And this is why I bailed.
Even if the person knows what all the terminology used means, it's an involved process of wire cutting and circuit rerouting.
 
Electrically cut everything fed off the blue/ brown
86....Trigger the relay with the blue / brown. IT IS IMPORTANT with some relays to trigger the 86 and ground the 85 because some/ many/ most contain an internal "spike" diode. Reversing polarity on the coil terminals will create a direct short.......until milliseconds later when the diode explodes

85.....Ground the relay coil or feed it through an "unobtrusive" switch which will make a simple anti--theft device

30....Feed the relay power through a fuse / breaker off the "big stud" on the starter relay

87....Connect the engine bay end of the "electrically cut" blue/ brown ---the load end, and connect that to the relay out contace, the NO or normally open.

mini-automotive-relay-wiring-840x.jpg

And this is why I bailed.
Even if the person knows what all the terminology used means, it's an involved process of wire cutting and circuit rerouting.
 
Electrically cut everything fed off the blue/ brown
86....Trigger the relay with the blue / brown. IT IS IMPORTANT with some relays to trigger the 86 and ground the 85 because some/ many/ most contain an internal "spike" diode. Reversing polarity on the coil terminals will create a direct short.......until milliseconds later when the diode explodes

85.....Ground the relay coil or feed it through an "unobtrusive" switch which will make a simple anti--theft device

30....Feed the relay power through a fuse / breaker off the "big stud" on the starter relay

87....Connect the engine bay end of the "electrically cut" blue/ brown ---the load end, and connect that to the relay out contace, the NO or normally open.

mini-automotive-relay-wiring-840x.jpg

And this is why I bailed.
Even if the person knows what all the terminology used means, it's an involved process of wire cutting and circuit rerouting.
 
20A should be enough. Bear in mind the original circuit was not protected at all LOL What is normally on that line (depending on year model) is the ignition circuit, the alternator field and regulator circuit, electric choke if used, some years "a couple" of smog doo dads.
 
Accessory load ( black wire feeding fuse box ) will still be on/through the ignition switch, less a second relay.
 
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