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DucRider said:

"Except it's not amperage that triggers the relay, it's voltage. Voltage is what causes the relay circuit to open or close."

Not to quibble, but it's the CURRENT flowing through the relay coil that generates magnetic field that moves the relay's armature.

It's the VOLTAGE that drives the current through the coil's resistance.

The only reason I mentioned the 170ma coil current was to show that for the relay control circuit, you don't need to use heavy-gauge wire to minimize voltage drop.
Correct, but you could put a small amount of current through and not cause a change in the relay if there isn't enough voltage to pull in/drop out the armature. Was simply stating that amperage has no bearing, otherwise it would defeat the purpose of using the relay.
 

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It was a question in reference to the fuse size for my own personal knowledge of the system. Geez! :rolleyes:
Not sure why you're getting offended and rolling eyes, I'm simply offering the correct answers so that someone reading this doesn't get confused. No need to take it the wrong way, but if you did that's unfortunate. Wish you the best in triggering relays using amperage with your soldered connections! :rofl:
 

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Not sure why you're getting offended and rolling eyes, I'm simply offering the correct answers so that someone reading this doesn't get confused. No need to take it the wrong way, but if you did that's unfortunate. Wish you the best in triggering relays using amperage with your soldered connections! :rofl:
No sweat. Was never offended. Was just seeking answers and I wasn't getting it, hence the rolled eyes. I guess that's the problem with forums. Someone asks a question, and everyone just beats around the bush with information that isn't relavent to the question.

In researching this LRA, I didn't see completely how each circuit was wired and how the circuits were fused. It's probably in here, I just didn't see it. I like this setup and plan on going this route if things look to be reliable. The setup for my Tundra uses a 3 amp fuse to trigger the relay, and 30 across the contacts, so I assumed it was similar. I already have a 40 amp circuit going to the rear of the FJ on the driver's side, and a 30 amp on the right side, both of which are currently using accessories. My big concern was whether or not I already had enough power back there to add this LRA, hence the specific questions. The last thing I want to do is overload any circuits. Does this make sense now? I originally thought about mounting my AUX battery in the rear but instead mounted it under the hood. I may rethink this, as most of my "camp" accessories run from the AUX, which are located at the rear of the FJ, but I may not as the weight offset from the battery being up front makes more sense.

Sorry for hacking up your thread, Chris!
 

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No sweat. Was never offended. Was just seeking answers and I wasn't getting it, hence the rolled eyes. I guess that's the problem with forums. Someone asks a question, and everyone just beats around the bush with information that isn't relavent to the question.

In researching this LRA, I didn't see completely how each circuit was wired and how the circuits were fused. It's probably in here, I just didn't see it. I like this setup and plan on going this route if things look to be reliable. The setup for my Tundra uses a 3 amp fuse to trigger the relay, and 30 across the contacts, so I assumed it was similar. I already have a 40 amp circuit going to the rear of the FJ on the driver's side, and a 30 amp on the right side, both of which are currently using accessories. My big concern was whether or not I already had enough power back there to add this LRA, hence the specific questions. The last thing I want to do is overload any circuits. Does this make sense now? I originally thought about mounting my AUX battery in the rear but instead mounted it under the hood. I may rethink this, as most of my "camp" accessories run from the AUX, which are located at the rear of the FJ, but I may not as the weight offset from the battery being up front makes more sense.

Sorry for hacking up your thread, Chris!
Really no reason to mount the aux battery in the back. Plus, if you're doing any sort of DC to DC charging you'll want it up front near the starter battery. My suggestion is you run a 4AWG wire from the engine bay, off your aux batt (with a 100A fuse at the batt) and then use a distribution block in the rear to divide the power out. For example, I have done this and run my ARB Dual compressor, JL Audio amplifier, rear DC power ports, etc. off of this line. Each item is fused at the distribution block as well. You wouldn't want to tap the LRA fuel pump power from this line, but rather do as Chris has done and install a relay off the switch. Keep the relay up near the switch and then run a thicker gauge wire to the pump. You could run this line in parallel with the 4AWG and then you're ready when the time comes to add the LRA tank.
 

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トヨタ Master
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Really no reason to mount the aux battery in the back. Plus, if you're doing any sort of DC to DC charging you'll want it up front near the starter battery. My suggestion is you run a 4AWG wire from the engine bay, off your aux batt (with a 100A fuse at the batt) and then use a distribution block in the rear to divide the power out. For example, I have done this and run my ARB Dual compressor, JL Audio amplifier, rear DC power ports, etc. off of this line. Each item is fused at the distribution block as well. You wouldn't want to tap the LRA fuel pump power from this line, but rather do as Chris has done and install a relay off the switch. Keep the relay up near the switch and then run a thicker gauge wire to the pump. You could run this line in parallel with the 4AWG and then you're ready when the time comes to add the LRA tank.
That's pretty much the way I will go. I originally didn't think that I would use that much power at the rear, but the more I think about it, the more it makes sense.
 

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That's pretty much the way I will go. I originally didn't think that I would use that much power at the rear, but the more I think about it, the more it makes sense.
Sounds good, if you need a list of parts used or any other info reach out and I'll be happy to help. Would highly suggest using Blu Sea MRBF fuses at the battery terminals and then MAXI fuses down line in the distribution blocks.
 

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Sounds good, if you need a list of parts used or any other info reach out and I'll be happy to help. Would highly suggest using Blu Sea MRBF fuses at the battery terminals and then MAXI fuses down line in the distribution blocks.
Thanks! I've already got the Blue Sea and everything else I stock at the shop here. Just need the time and motivation. Spring time so the Mrs has me on honey dos for a bit. Speaking of which, I've still got boxes of stuff for the FJ that I really haven't had time for in over a year. The plan is to finish everything this year. We'll see how that goes.
 

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Discussion Starter #188
No sweat. Was never offended. Was just seeking answers and I wasn't getting it, hence the rolled eyes. I guess that's the problem with forums. Someone asks a question, and everyone just beats around the bush with information that isn't relavent to the question.

In researching this LRA, I didn't see completely how each circuit was wired and how the circuits were fused. It's probably in here, I just didn't see it. I like this setup and plan on going this route if things look to be reliable. The setup for my Tundra uses a 3 amp fuse to trigger the relay, and 30 across the contacts, so I assumed it was similar. I already have a 40 amp circuit going to the rear of the FJ on the driver's side, and a 30 amp on the right side, both of which are currently using accessories. My big concern was whether or not I already had enough power back there to add this LRA, hence the specific questions. The last thing I want to do is overload any circuits. Does this make sense now? I originally thought about mounting my AUX battery in the rear but instead mounted it under the hood. I may rethink this, as most of my "camp" accessories run from the AUX, which are located at the rear of the FJ, but I may not as the weight offset from the battery being up front makes more sense.

Sorry for hacking up your thread, Chris!
No worries, its always interesting to hear how others have wired up their mods. I have to admit I was a little confused about what you were asking also. Makes sense now. The only fuses in the LRA circuit are the fuse for the power wire to the APEXUS switch (which also drives my voltage converter) and the fuse for the power to the relay. The first fuse is 1 amp, the relay fuse is 5amp because the pump shouldn't pull any more than 3 amp.
 

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I'm just a slow old Fa rt........ :rofl::rofl:
Case in point! A guy could trip over his bottle of Geritol tomorrow! :surprise
Gitter dun', son! :eek:ld: :grin
 

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Really no reason to mount the aux battery in the back. Plus, if you're doing any sort of DC to DC charging you'll want it up front near the starter battery. My suggestion is you run a 4AWG wire from the engine bay, off your aux batt (with a 100A fuse at the batt) and then use a distribution block in the rear to divide the power out. For example, I have done this and run my ARB Dual compressor, JL Audio amplifier, rear DC power ports, etc. off of this line. Each item is fused at the distribution block as well. You wouldn't want to tap the LRA fuel pump power from this line, but rather do as Chris has done and install a relay off the switch. Keep the relay up near the switch and then run a thicker gauge wire to the pump. You could run this line in parallel with the 4AWG and then you're ready when the time comes to add the LRA tank.
(Now this is trending back to being more applicable to the original thread topic ...)

DucRider, I'm not sure I would agree with some of your suggestions, maybe you can provide some additional information that would help bring things into focus.

In your own setup you ran a #4 AWG wire to the rear of the vehicle to a power distribution block, which supplies power to a twin ARB compressor, audio amp, and DC power ports. This is all reasonable, and sized to support the 70A full-load current of the compressor. You didn't state if you used a local chassis ground, or ran a second #4 AWG ground wire back from the engine bay.

(Coincidentally, I have an almost identical circuit topology in my FJ, powering a single ARB pump, a fridge, and an aux 12VDC outlet in the rear. I have a 50A marine circuit breaker in the engine bay, and individual aircraft circuit breakers for each load on the rear power distribution panel.)

What I'm not clear on is why you are suggesting NOT to power the LRA fuel pump from this circuit, but instead run another set of conductors back from the engine bay to the pump, with the pump control relay close to the power source and the the manual pump switch.

It's extremely unlikely (and certainly not recommended) that you would be running the compressor and the fuel transfer pump simultaneously. So the concern would be the total load current when powering the audio amp and/or the aux DC outlet at the same time as the fuel transfer pump. I don't know anything about your audio amp or what kind of loads you might be powering from the aux DC outlet, but it would seem that a circuit that could safely supply 70A for the compressor would be more than adequate for these non-compressor loads without experiencing any significant voltage drop.

I think a better setup would be to power the fuel pump from your existing rear DC bus, locating the relay near the rear distribution block, and running only relatively small-gauge wiring back from the cab-mounted pump control switch to the relay coil. Less wire carrying pump load current, less wire cost, less weight, etc. Normally you would want to locate the load control relay as close to the load as possible.

Maybe I'm missing some other factor?
 

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(Now this is trending back to being more applicable to the original thread topic ...)

DucRider, I'm not sure I would agree with some of your suggestions, maybe you can provide some additional information that would help bring things into focus.

In your own setup you ran a #4 AWG wire to the rear of the vehicle to a power distribution block, which supplies power to a twin ARB compressor, audio amp, and DC power ports. This is all reasonable, and sized to support the 70A full-load current of the compressor. You didn't state if you used a local chassis ground, or ran a second #4 AWG ground wire back from the engine bay.

(Coincidentally, I have an almost identical circuit topology in my FJ, powering a single ARB pump, a fridge, and an aux 12VDC outlet in the rear. I have a 50A marine circuit breaker in the engine bay, and individual aircraft circuit breakers for each load on the rear power distribution panel.)

What I'm not clear on is why you are suggesting NOT to power the LRA fuel pump from this circuit, but instead run another set of conductors back from the engine bay to the pump, with the pump control relay close to the power source and the the manual pump switch.

It's extremely unlikely (and certainly not recommended) that you would be running the compressor and the fuel transfer pump simultaneously. So the concern would be the total load current when powering the audio amp and/or the aux DC outlet at the same time as the fuel transfer pump. I don't know anything about your audio amp or what kind of loads you might be powering from the aux DC outlet, but it would seem that a circuit that could safely supply 70A for the compressor would be more than adequate for these non-compressor loads without experiencing any significant voltage drop.

I think a better setup would be to power the fuel pump from your existing rear DC bus, locating the relay near the rear distribution block, and running only relatively small-gauge wiring back from the cab-mounted pump control switch to the relay coil. Less wire carrying pump load current, less wire cost, less weight, etc. Normally you would want to locate the load control relay as close to the load as possible.

Maybe I'm missing some other factor?
Good points, here are answers to your questions:

- Grounding: I did all of my grounds locally on the chassis
- Multiple loads at once: Agree, the circuit could handle all of this and it wouldn't overload it
- Where to power pump from: I only suggested putting a relay up front as he'd be able to wire it in near the switch, but you're correct, he could power it further down the line (near back of vehicle) and run the trigger wire for the relay, which would be thinner AWG wire. However, we're taking about 14AWG vs 18/20AWG, so to me it's not really a big deal (not like my winch that is triggered by 18AWG, but runs power across 0AWG).

Good discussion!
 

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I'm in the middle of my tank installation and found something that is different on my 2013 vs. what comes with the kit. The Fuel Pump Control Module on my 2013 has a mounting bracket with screws that come in from the top and bottom vs. the other version which mounts in from the back. The bracket that comes with the LRA kit doesn’t work for my style module, so I had to improvise (big thanks to @rx100 for discussing with me on FaceTime while he was driving!). Drilled some holes and connected them together. Figured others with a 2013-2014 would want to know this before diving in.
 

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Got the tank mounted and all hoses connected today. Will wire the fuel pump tomorrow and be ready to go.

A word of advice when tightening the nuts on the bracket that the U-Bolts go through: Alternate back and forth when tightening the two (front to rear of vehicle). The bracket doesn't give much room to get a socket around the nuts that are closest to the tank, so if you tighten the opposing side of the U-Bolt too much it'll pull the thread closer to the tank and you're screwed.

I found another issue with the LRA kit that needs to be corrected. The white plastic rollover valve that comes with the LRA tank has a 1/4" barb fitting. The side you connect this to on the LRA fill neck is a 5/16" barb fitting. The hose that's provided for this is 5/16". Yes, it's only 1/16 of an inch in difference so you could just tighten it down more, but I want everything to match right so that I don't go throwing codes or having any leaks. I didn't realize this until after the LRA filler neck was installed and connected to the OEM section that I cut-off, otherwise I would get the proper fitting with 1/4" barb and then run 1/4" hose the hole way through (this is the proper way). Instead I took the leftover section of 1/4" hose that I cut-off from the OEM rollover tube to the LRA neck and connected it to the white plastic rollover valve on the LRA tank. I ordered a hose barb adapter that goes from 1/4" to 5/16" (will arrive tomorrow) and will connect the 1/4" hose to a section of 5/16" and then up to the neck. I shouldn't have to be doing this so I'll advise Cruiser Bro's of this, as I believe it needs to be updated in the kit.
 

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Quick update - tested it out last night, put in 5 gallons, transferred it to the main. All went through smooth. Burned some of the fuel, added 10 more gallons, then transferred it. All went well and it filled the main. Started the vehicle this morning and had CEL and TRAC OFF illuminated. Pulled the codes and got P0441 and P0455. These imply something is wrong with the EVAP (charcoal canister) system. I checked and everything looks good from a hose connection perspective, so I'm wondering if it's an issue with the gas cap. I pulled it, tightened it down and cleared the codes. I'm all ears for anyone else that may have experienced these issues. Let's hope it doesn't return!
 
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