Do i need a relay?
#1
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Year: 1994
Model: Grand Cherokee
Engine: 4.0
Do i need a relay?
If im running some old school kc type lights do I need a relay or can I wire it straight through the switch. Also, are yall using a premade harness or are you bulding as you go? Got some TJ factory lights and some baja offroad lights for dirt cheap.
#2
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Year: 1997
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I recommend a harness. Anything stronger than stock lighting is probably going to burn your switch up. Even upgrading your harness with stock lighting increases light output.
As far as buying or building a harness is up to you. If you have wire and relays laying around I'd say build. Just as easy to buy one online for 20-30 bucks.
As far as buying or building a harness is up to you. If you have wire and relays laying around I'd say build. Just as easy to buy one online for 20-30 bucks.
#4
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Year: 1994
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To clarify, it will be independent of the stock lights, just was curious as to whether most built their own harness or bought one. As for the relays, I have a few laying around. Is there any specific kind I need?
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Year: 1996
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Amp draw is a simple mathematical calculation. Divide the total number of watts by the system's volts. For example, a 100-watt bulb in a 12-volt system will draw 8.3 amps.
(100w / 12v = 8.3a)
(100w / 12v = 8.3a)
#6
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Year: 1994
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@Cane, since you seem to know what youre talking about with electrical and I dont lol.
My plan is to put the two TJ fog lights on my bumper somewhere and run them to one switch.
Then put the 4 baja lights on the roof and run the outside two on a switch and the inside tow on a switch so that I can run 2 or 4. So one relay per switch should be adequate, correct?
My plan is to put the two TJ fog lights on my bumper somewhere and run them to one switch.
Then put the 4 baja lights on the roof and run the outside two on a switch and the inside tow on a switch so that I can run 2 or 4. So one relay per switch should be adequate, correct?
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Year: 1996
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yes, so basically if your fog lights are independent from your baja lights, you'll have 3 4-pin relays, each activated by a switch.
here's a basic example of the wiring (for one relay), using an on/off switch
86 to ground
30 to the 12v source (battery)
85 to switch (your switch needs to transmit a signal to the relay, so it must be wired to a 12v source too)
87 to the load (your lights)
that means that when you flip the switch on, the coil energises and connects 30 and 87 together, making the current go straight from the battery to your lights, through the relay instead of the switch. do that x3 and you should be good to go.
here's a basic example of the wiring (for one relay), using an on/off switch
86 to ground
30 to the 12v source (battery)
85 to switch (your switch needs to transmit a signal to the relay, so it must be wired to a 12v source too)
87 to the load (your lights)
that means that when you flip the switch on, the coil energises and connects 30 and 87 together, making the current go straight from the battery to your lights, through the relay instead of the switch. do that x3 and you should be good to go.
Last edited by Cane; 04-19-2017 at 02:34 PM.
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#8
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Year: 1994
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yes, so basically if your fog lights are independent from your baja lights, you'll have 3 4-pin relays, each activated by a switch.
here's a basic example of the wiring (for one relay), using an on/off switch
86 to ground
30 to the 12v source (battery)
85 to switch (your switch needs to transmit a signal to the relay, so it must be wired to a 12v source too)
87 to the load (your lights)
that means that when you flip the switch on, the coil energises and connects 30 and 87 together, making the current go straight from the battery to your lights, through the relay instead of the switch. do that x3 and you should be good to go.
here's a basic example of the wiring (for one relay), using an on/off switch
86 to ground
30 to the 12v source (battery)
85 to switch (your switch needs to transmit a signal to the relay, so it must be wired to a 12v source too)
87 to the load (your lights)
that means that when you flip the switch on, the coil energises and connects 30 and 87 together, making the current go straight from the battery to your lights, through the relay instead of the switch. do that x3 and you should be good to go.
#9
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Year: 1994
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Any thoughts on where to locate the switches? Im thinking on the front face of the center console. Also, can I just run a single 12v and tie it into all 3 switches?
#10
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You could also run 12v to 30 and 86 and make 85 a switchable ground. Sometimes I use this method for cooling fans etc because if the switch shorts out the device just stays on.
#11
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All three switches can be on the same 12v supply- the amperage needed to throw a relay is minimal and they won't interfere with each other. Your power going out of each switch needs to be isolated, as well as to and from each relay. The supply for your switches should also come from a 12v ignition source or your headlight switch so when you turn the Jeep off and leave the switches on they don't stay on.
And it's great you're using relays, but don't forget the fuses too!
Last edited by alpine.adrenaline; 04-19-2017 at 04:30 PM.
#13
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Year: 1994
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Unless you light the switches, consider putting them somewhere you can easily find them in the dark.
All three switches can be on the same 12v supply- the amperage needed to throw a relay is minimal and they won't interfere with each other. Your power going out of each switch needs to be isolated, as well as to and from each relay. The supply for your switches should also come from a 12v ignition source or your headlight switch so when you turn the Jeep off and leave the switches on they don't stay on.
And it's great you're using relays, but don't forget the fuses too!
All three switches can be on the same 12v supply- the amperage needed to throw a relay is minimal and they won't interfere with each other. Your power going out of each switch needs to be isolated, as well as to and from each relay. The supply for your switches should also come from a 12v ignition source or your headlight switch so when you turn the Jeep off and leave the switches on they don't stay on.
And it's great you're using relays, but don't forget the fuses too!
#14
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#15
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I ran 2 150w lights for a couple minutes without relays once... before the smell of something burning took place . Switch pretty much melted.
I had a after market LED lighted switch on the dash that blinded me, had to put black tape over it. Damn thing would burn a hole in your retina. Didn't notice til nightime when I would actually use the flood lights. Not saying what you picked out will, just a fyi.
I had a after market LED lighted switch on the dash that blinded me, had to put black tape over it. Damn thing would burn a hole in your retina. Didn't notice til nightime when I would actually use the flood lights. Not saying what you picked out will, just a fyi.