Adding in a 3rd light to a 2 leg wire harness
03-01-2015, 06:00 PM
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JK Enthusiast
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Adding in a 3rd light to a 2 leg wire harness
I have 2 3-4 inch pods on my A-pillars. I am going to hook up a 20" light bar on the bumper and I want to put it on the same relay. How I understand it is 18w+18w+120w/12v=13a so I should be fine on a 30a relay correct? Would I just take off the wires on 87 and put a terminal end back on all 3 wires. Then ground the black or do I need to run black back to the relay as well? It might be a stupid question but I'm new to wiring things myself and trying to learn
03-02-2015, 01:50 AM
#2
JK Junkie
The ground does not need to go back to the relay. Adding a third wire to pin 87 will change the requirements of the wire gauge and fuse that connects to pin 30. All 3 lights will now be fed through pin 30 and the wire size and fuse must be rated higher. Use an online calculator to determine what gauge the pin 30 wire needs to be based on length and current. For example, up to 20' can be 10 gauge using the calculator.
Wire Size Calculator
Since the original pods were only 3 amps combined, most likely there is a small gauge wire installed that needs to be replaced.
So you could either upgrade the fuse and wiring that feeds pin 30 as well or use another relay triggered off the same switch.
Wire Size Calculator
Since the original pods were only 3 amps combined, most likely there is a small gauge wire installed that needs to be replaced.
So you could either upgrade the fuse and wiring that feeds pin 30 as well or use another relay triggered off the same switch.
Last edited by 14Sport; 03-02-2015 at 01:54 AM.
03-02-2015, 03:24 AM
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I knew you were going to be the one to jump in! I admire your diagrams. If you don't mind, how would I go about wiring in a relay on the same switch since that would be the same end result
03-02-2015, 04:31 AM
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Actually the wire harness I used was the Rough Country one with 40a relay and 30a fuse that said it could be used for up to a 50 in bar(~300w), I'll go check the wire gauge at lunch but the wires seemed pretty beefy, so it may be good on the 30 pin
Last edited by MDRoots; 03-02-2015 at 04:37 AM.
03-02-2015, 05:07 AM
#5
JK Junkie
As long as the fuse and wiring can handle it you should be good.
To add another relay triggered by the same switch, you would wire it accordingly:
Pin 30 - fused to battery.
Pin 87 - to light positive, light ground directly to ground.
Pin 85 - jumper from pin 85 on a pillar lights (if that is the pin that is switched on the a pillars).
Pin 86 - ground.
Pins 85 and 86 may be reversed on your a pillar lights. If so, wire your new relay the same. The switch jumper from the a pillar relay must come from the pin that has the switch on it.
And thanks. Appreciate it.
To add another relay triggered by the same switch, you would wire it accordingly:
Pin 30 - fused to battery.
Pin 87 - to light positive, light ground directly to ground.
Pin 85 - jumper from pin 85 on a pillar lights (if that is the pin that is switched on the a pillars).
Pin 86 - ground.
Pins 85 and 86 may be reversed on your a pillar lights. If so, wire your new relay the same. The switch jumper from the a pillar relay must come from the pin that has the switch on it.
And thanks. Appreciate it.
Last edited by 14Sport; 03-02-2015 at 06:26 AM.
03-02-2015, 12:33 PM
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Thank you for all your help, I went ahead and ordered the bar with a harness just in case for the future, I think it was 14 or 16 gauge wire but from the battery to pin 30 is less than 2 feet
03-02-2015, 12:48 PM
#7
JK Junkie
