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Discussion Starter · #1 ·
Well, if there is one thing I've learned from modding vehicles over the years............... it's always something.

I figure someone on this forum has dealt with this so I'll ask here before calling PIAA.

I pulled the trigger on a new air dam this week and I bought a second pair of PIAA 520 ATP's to add to the ones already installed.

When I pulled them out of the box, I found the wiring harness is way too short to run up to the roof rack. Apparently it was made with bumper mounting in mind.

So here is my dilemma.

The 520's that are already installed (by a previous owner) are wired up using a piaa relay and a toyota fog light switch. The relay looks identical to the one that came with my new lights.



The problem is there is no information on this relay, or in the instructions that gives any rating information. I also haven't found any using google.

My question is, can I run all 4 lights off the single relay?
Or should I use a single relay for each pair of lights?

No matter what I do, I have to do some splicing and soldering to do the install.

Furthermore, can I use the single OEM switch to activate both relays if I go that route or should I purchase a second switch? I don't like the one PIAA included. I'd like to keep a factory look.
 

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I would not try running both sets of lights off the same relay. What comes in the kit is rated for what comes in the kit. 2 lights to one relay.

You can however use the same switch to trigger both relays thus being able to use the same switch to control all four lights.

It takes milliamps to activate and maintain the relay in an open state. The toy fog light switch will take more then enough amps to run two relays.
 

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Discussion Starter · #3 ·
I would not try running both sets of lights off the same relay. What comes in the kit is rated for what comes in the kit. 2 lights to one relay.

You can however use the same switch to trigger both relays thus being able to use the same switch to control all four lights.

It takes milliamps to activate and maintain the relay in an open state. The toy fog light switch will take more then enough amps to run two relays.
Cool thanks.
I figured the switch would be good enough. But since I didn't install it and don't really know much about it, I wasn't sure.

Sucks, that I need to install 2 relays. They should sell a setup for 4 lights.
 

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Discussion Starter · #5 ·
As suggested above, 1 switch is fine...
Why don`t you just extend existing harness that is too short? all you need is 2 connectors..
That is what I'm going to do.
I was just hoping I could daisy chain the lights to the other 2 currently on the roof.
 

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Cool thanks.
I figured the switch would be good enough. But since I didn't install it and don't really know much about it, I wasn't sure.

Sucks, that I need to install 2 relays. They should sell a setup for 4 lights.
P.S. you can run all 4 in the same circuit if you rebuild the harness with heavier gauge wire and 30A relay and the fuse.
Yes they do make higher rated relays but the ones in the kit are rated for the two lights that come with the kit. My guess is they are 15 amp relays but I don't know what the wattage your lights are so I can't say for sure.

My 2 backup and 2 fog lamps are on 2 separate relays and the 4 lamps on the roof are on one 30 amp and the 4 on the brush bar are on a separate 30 amp relay. That's right I've got 12 lights on my rig :bigthumb:

My wiring is all custom. The only reason I bought the PIAA kits was because they were cheaper then buying the lamps by themselves. All the PIAA wiring went in the trash.
 

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The PIAA relay that came with mine was rated at 30amps and I wired four 520s through one relay and it worked flawlessly for years. I am not suggesting that is the case with your relay but you might be able to find out from PIAA what the relay is rated that you already have. If it is rated at 30 you are more than fine runnign all four light off of it any less and I would think you might burn up a switch depending on what your switch is rated at. If you are using the Toyota I believe it is rated at 20 amps so it is pretty stout switch. That is just my 2 cents.
 

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Discussion Starter · #9 ·
My 2 backup and 2 fog lamps are on 2 separate relays and the 4 lamps on the roof are on one 30 amp and the 4 on the brush bar are on a separate 30 amp relay. That's right I've got 12 lights on my rig :bigthumb:
Damn, I'm only going to have 8. You have officially won the contest. :)

The PIAA relay that came with mine was rated at 30amps and I wired four 520s through one relay and it worked flawlessly for years. I am not suggesting that is the case with your relay but you might be able to find out from PIAA what the relay is rated that you already have. If it is rated at 30 you are more than fine runnign all four light off of it any less and I would think you might burn up a switch depending on what your switch is rated at. If you are using the Toyota I believe it is rated at 20 amps so it is pretty stout switch. That is just my 2 cents.
I called PIAA and still couldn't get the rating of the relay out of them. However, they told me absolutely not to run 4 lights on a single relay/harness as they are only made for 2 lights.

Probably just covering their ass, but I'm going to take everyones advice, play it safe and install both relays.
I'd hate to burn my FJ to the ground.:cheers:
 

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Cool thanks.
I figured the switch would be good enough. But since I didn't install it and don't really know much about it, I wasn't sure.

Sucks, that I need to install 2 relays. They should sell a setup for 4 lights.
The reason they usually limit harnesses to two lights is for protection - with only two lights, it's easier to rate a relay and fuse to blow before causing wiring damage if a short in one light occurs. With four lights, a smaller short could be enough to damage wiring without blowing the much higher rated fuse...so, it's for your protection to use the minimum fuse / relay rating to stop further damage if a problem occurs...:rocker:

you can, however, use one switch to control as many relay circuits as you like without issue....:cheers:
 

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I, too, scrapped all the wiring harnesses I received in the PIAA kits, but I simply used the wiring that Toyota provided in the existing FJ electrical system. I used a 30amp DENSO relay and 30amp fuse, both of which plugged right into the main fuse box in the engine compartment. These, in cooperation with the factory Off-Road light switch (also plug and play), provide clean 12v power to the driver-side A pillar connection I used to take power to the roof. Easy day.
 

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I, too, scrapped all the wiring harnesses I received in the PIAA kits, but I simply used the wiring that Toyota provided in the existing FJ electrical system. I used a 30amp DENSO relay and 30amp fuse, both of which plugged right into the main fuse box in the engine compartment. These, in cooperation with the factory Off-Road light switch (also plug and play), provide clean 12v power to the driver-side A pillar connection I used to take power to the roof. Easy day.
Did you also upgrade the wiring gauge to accomodate the 30amp fuse and relay?
 
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