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Discussion Starter · #1 ·
I have 5 new hella 55W flood lights for under the FJ. I plan to place two up front two in the middle and one just behind the rear diff. I have the bud built skids and I am having an issue with where best to place the middle ones. Does anyone have any ideas?
I am also new at all the auto electrical so here come the questions....

1. How many lights can I place on one relay and what size relay do I need to get? I looked at the bosch ones online http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=330-073[/URL] they seem to be 30-40amps?
2. What gage wire is needed for this set up?
3. If I have more then one relay what is the best way to wire it to the same switch?
4. Anything else I should look at?

I have a basic understanding of this but I am by no means an expert if someone has a design that works let me know the details. Also if there are any electrical experts out there that would like to send a wiring diagram I would more than happily buy them a beer:cheers: in Ouray!

Thanks:bigthumb:
 

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Discussion Starter · #3 ·
Check out what one of our esteemed AZFJ'ers did!

You'll like it. ;)

Add up the amperage of the lights. Get a relay rated to an amperage greater than that.

AZFJ › Forums › Technical Discussion › FJ 4x4 tech › Not quite rock lights
Thanks for the link. I am reading through it right now. I have also seen these mounted with heavy magnets that work? My lights are grounded through the mounts my only concern is if I have a magnet on the top side of my skid is a magnet a good ground contact?
 

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If you sanded the paint from the metal underneath, a magnet would probably conduct enough current, or at least hold a conductor steady enough to conduct... but why? If you're going to wire the things in, then why have a flimsy mount? Why worry about knocking the things off with jarring rock hits?
 

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Discussion Starter · #5 ·
Check out what one of our esteemed AZFJ'ers did!

You'll like it. ;)

Add up the amperage of the lights. Get a relay rated to an amperage greater than that.

AZFJ › Forums › Technical Discussion › FJ 4x4 tech › Not quite rock lights
With the amperage you get 4.8 or so with five lights less than 25 so my questions is that a 30 amp relay should cover it. However, most people seem to wire each light or only a few light to each relay is there a benefit to this or just over kill?
 

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It's not so much about the capacity of the relay as it is the options available with more switches. Some light kits come with a pre-existing wiring harness packaged together with 2 lamps. Typically, if someone were to buy 2 sets, they'd end up with 4 lamps, 2 relays, and 2 switches. If these are all forward facing, they could easily be wired to one relay safely.

However, if you run a set of driving lights, a set of side-facing trail lights, and a set of reverse facing lights... you probably want to put these on three separate switches (forward, side and rear) just to be able to make a choice of what needs to be on and what needs to be off. The guy behind you on the trail might have an opinion on the matter, for example.

If you're doing down-facing crawl lights, then there's no reason not to have them on the same switch/relay. I can't think of a reason that you'd want some but not all of the lights on.
 

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Personally I would prefer the option to at least set them up on two seperate circuits. This would require two 30 AMP relays. You can pick up the relays at most automotive stores. I dont think that a magnet will serve your purpose well, but worth a try if you choose. Check out the thread below for a wiring diagram that will work for you. You stated that your lights ground through the mount so disregard the ground going back to the battery.

http://www.fjcruiserforums.com/forums/stereo-electronics/49156-basic-aux-lighting-wiring.html
 

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Discussion Starter · #8 ·
Personally I would prefer the option to at least set them up on two seperate circuits. This would require two 30 AMP relays. You can pick up the relays at most automotive stores. I dont think that a magnet will serve your purpose well, but worth a try if you choose. Check out the thread below for a wiring diagram that will work for you. You stated that your lights ground through the mount so disregard the ground going back to the battery.

http://www.fjcruiserforums.com/forums/stereo-electronics/49156-basic-aux-lighting-wiring.html
I have seen the relays at the store are most of these waterproof or at least water resistant? Most have five terminals what is the fifth one for?
I also noticed in your link http://www.fjcruiserforums.com/forums/attachments/stereo-electronics/20775d1204083344-basic-aux-lighting-wiring-aux-light-custom-.jpgthat you do not use a fuse or ground from the switch are there advantages to do this or is it not needed?
If I use two or three relays what is the best way to tie them all in so that I only need one switch. Can I just take and solder them together to the positive lead on the switch?
If I had two lights on my relay that would be about 10 amps, so a 10 or 20 amp fuse should be more than enough to the battery correct?
Also one final question I seem to be running out or room on the positive battery terminal post for mounts with driving lights, cb, winch, and now rock lights. I know this means that I should be running dual batteries. Is there a way to extend that mounting bolt about a 1/8" by replacing it or should I go to a fuse block off the battery for a cleaner and better look?
Thanks for all the help I have no issue with drilling holes in the side of the fender for a snorkel or tearing the engine apart but, electrical is like voodoo to me plus I am anal and I need to have all the answers before I do anything, oh wait that is most of us!:lol:

Jeremy
 

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I have seen the relays at the store are most of these waterproof or at least water resistant? Most have five terminals what is the fifth one for?
I also noticed in your link http://www.fjcruiserforums.com/forums/attachments/stereo-electronics/20775d1204083344-basic-aux-lighting-wiring-aux-light-custom-.jpgthat you do not use a fuse or ground from the switch are there advantages to do this or is it not needed?
If I use two or three relays what is the best way to tie them all in so that I only need one switch. Can I just take and solder them together to the positive lead on the switch?
If I had two lights on my relay that would be about 10 amps, so a 10 or 20 amp fuse should be more than enough to the battery correct?
Also one final question I seem to be running out or room on the positive battery terminal post for mounts with driving lights, cb, winch, and now rock lights. I know this means that I should be running dual batteries. Is there a way to extend that mounting bolt about a 1/8" by replacing it or should I go to a fuse block off the battery for a cleaner and better look?
Thanks for all the help I have no issue with drilling holes in the side of the fender for a snorkel or tearing the engine apart but, electrical is like voodoo to me plus I am anal and I need to have all the answers before I do anything, oh wait that is most of us!:lol:

Jeremy
I'm not going to address all of your questions because you deserve a higher level of expertise than I can offer, on several of them. In regard to the multiple relays from one switch, there are some choices. One option would be to run the switch legs in series. If you do this, I'd measure the voltage drop across each to make sure it didn't fall off too much. They should offer measureable voltage drop because of resistance. They activate an electromagnet against a spring.

I would advise NOT to wire them in parallel. This could make your switch into the most resistant part of the curcuit... which would be embarassing.

Another way is to daisy chain them. You can incorporate a relay in parallel with a set of lights off of another relay. You throw the switch, it activates the relay which turns on two lights AND a relay for another set of lights... Whatever you do, put a fuse in line with the power leg of each circuit.

As to the battery terminal... think about it for a sec. The battery is the power soucre when the engine isn't cranking the alternator. However, most of the time, the engine/alternator is driving your lights and electrical systems AND charging the battery. The battery terminal is a convenient location to find the positive side of the electrical system, but there's no magic. If you build an appropriately insulated junction box, you can put it anywhere.

If you want to deep discharge the accumulated energy stored in the battery frequently, then a dual battery setup isn't a bad idea. I'd recommend this if you do a lot of winching at night under the full use of all your lights.
 

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Discussion Starter · #10 ·
Thanks for all the help. Found mounting points for all but one light I need to find what the bolt size and thread count is for the nuts welded in the frame? I then ran 14 gauge wire to relays and the relays to a switch.
55W / 12V = about 4.8 AMPS if I wire the lights in series than the AMPS are not added correct it is just a straight 4.8AMPS? So the wire should just have 4.8 AMPS so a 30 AMP relay should have no problem. My only questions is if I wire all lights in series I should be able to run 10 lights on one relay correct? I know the set up I have works for now I just want to make sure I am smart on all this and you save money and space under the FJ hood for more mods. I am down two the last place to mount wires on the positive terminal on the battery. I should finish this up on Mon and I will have pics.
One final question is there a pic of the interior fuse box that labels the blank ignitions fuse holes? I have the add a fuses but I already have two in there. Thanks for any links or pics on the open holes.
 

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Thanks for all the help. Found mounting points for all but one light I need to find what the bolt size and thread count is for the nuts welded in the frame? I then ran 14 gauge wire to relays and the relays to a switch.
55W / 12V = about 4.8 AMPS if I wire the lights in series than the AMPS are not added correct it is just a straight 4.8AMPS? So the wire should just have 4.8 AMPS so a 30 AMP relay should have no problem. My only questions is if I wire all lights in series I should be able to run 10 lights on one relay correct? I know the set up I have works for now I just want to make sure I am smart on all this and you save money and space under the FJ hood for more mods. I am down two the last place to mount wires on the positive terminal on the battery. I should finish this up on Mon and I will have pics.
One final question is there a pic of the interior fuse box that labels the blank ignitions fuse holes? I have the add a fuses but I already have two in there. Thanks for any links or pics on the open holes.
Wiring them in series is a bad idea. If they're all about the same resistance then you'll have the same fraction of the 13.2 nominal volts across each one. They'll barely shine. You need the FULL voltage across each one. You can't get something for nothing.

For MORE LIGHT you need to use MORE ELECTRICITY.

Wire them in parallel. Add the currents. Make sure the current draw on your proposed wire runs is less than the capacity of the relay feeding it.

For that matter, make sure that you use wire that's sufficient for the current you plan to run through the relay too! 14 may be a bit small. Consider 12.
 

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Discussion Starter · #12 · (Edited)
Wiring them in series is a bad idea. If they're all about the same resistance then you'll have the same fraction of the 13.2 nominal volts across each one. They'll barely shine. You need the FULL voltage across each one. You can't get something for nothing.

For MORE LIGHT you need to use MORE ELECTRICITY.

Wire them in parallel. Add the currents. Make sure the current draw on your proposed wire runs is less than the capacity of the relay feeding it.

For that matter, make sure that you use wire that's sufficient for the current you plan to run through the relay too! 14 may be a bit small. Consider 12.
Thanks

It was late last night I meant parallel for the lights I got that from the previous post. Looking at the AWG chart here: http://www.eskimo.com/%7Ebillb/tesla/wire1.txt It almost seems that I should be using 10 or 11 AWG if there are 4.6 Amps / light two lights would be just over 9 Amps. I think that might be overkill? However, if you look at the chart at the bottom of this page it seems for a 12V system with 10 AMPS at 10 feet 14 AWG is more than enough? It is always nice to have someone check your work it gives me the piece of mind that I need to sleep at night thanks for sticking with all the questions once I do it right the first time all other mods will be a breeze.

Jeremy
 

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I have seen the relays at the store are most of these waterproof or at least water resistant? Most have five terminals what is the fifth one for?
I also noticed in your link http://www.fjcruiserforums.com/forums/attachments/stereo-electronics/20775d1204083344-basic-aux-lighting-wiring-aux-light-custom-.jpgthat you do not use a fuse or ground from the switch are there advantages to do this or is it not needed?
If I use two or three relays what is the best way to tie them all in so that I only need one switch. Can I just take and solder them together to the positive lead on the switch?
If I had two lights on my relay that would be about 10 amps, so a 10 or 20 amp fuse should be more than enough to the battery correct?
Also one final question I seem to be running out or room on the positive battery terminal post for mounts with driving lights, cb, winch, and now rock lights. I know this means that I should be running dual batteries. Is there a way to extend that mounting bolt about a 1/8" by replacing it or should I go to a fuse block off the battery for a cleaner and better look?
Thanks for all the help I have no issue with drilling holes in the side of the fender for a snorkel or tearing the engine apart but, electrical is like voodoo to me plus I am anal and I need to have all the answers before I do anything, oh wait that is most of us!:lol:

Jeremy

If your switch has a light(s) that come on when activated and or with the dash lights the switch will require it's own ground. I was remiss in not showing a fuse in the power source to the switch.

The easiest way to fire two relays from on switch is to use a DPST switch. This is a Double Pole Single Throw. This swith will have two outputs rather than one as on a SPST switch.

A 20 AMp fuse on the power to the relay is fine.

Running out of space on the Pos terminal of the battery is quite common. You may wish to consider a dual battery setup and would certainly help with winching and use of multiple lighting. It may save you in case you drain the main battery and require a backup for starting. There are several options for increasing how many leads you can attach to the POS side of your battery. Check out the battery section of your local auto parts store, they generally have several differnt battery post connectors to chose from.
 

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Discussion Starter · #15 ·
Thanks to everyone for the help on this install. :bigthumb:Here is the final verdict: 4 Hella flood lights 55W waterproof housing with 12 AWG two lights on each relay and a switch mounted inside. Thanks to everyone that stuck with me on the questions. I will get some pics of the lights and the locations soon the important part is now my FJ is sitting out in driveway burning a hole in the blacktop :rocker: I will have my 3 year old on fire watch tonight just to make sure the install is trail ready. He has to earn his 4x4 in this house:rofl:
 

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I am interested in what Hella light you mounted by the diff and how you mounted it, i.e., existing hole, bracket, etc. A picture would be great. I have the MAF tank but still have a little room by the diff.


Thanks to everyone for the help on this install. :bigthumb:Here is the final verdict: 4 Hella flood lights 55W waterproof housing with 12 AWG two lights on each relay and a switch mounted inside. Thanks to everyone that stuck with me on the questions. I will get some pics of the lights and the locations soon the important part is now my FJ is sitting out in driveway burning a hole in the blacktop :rocker: I will have my 3 year old on fire watch tonight just to make sure the install is trail ready. He has to earn his 4x4 in this house:rofl:
 
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