4Runner4Leon
Senior Member
Thanks for the feedback, the 10 relay option sounds interesting. How much did that custom unit, with the longer wire runs, cost you?
Also, did you go with positive or negative switched?
Strategies for upgrading electrical circuits
- Thread starter 4Runner4Leon
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Thanks for the feedback, the 10 relay option sounds interesting. How much did that custom unit, with the longer wire runs, cost you?
Also, did you go with positive or negative switched?
If I remember the 10 relay ran me about $200ish. I ended up upgrading the positive and negative wire my self. Along with extending the wires my self to my needs. Really hard to know what lenght you’ll need. But it was no biggie.
violation
Member
that's the beauty of this set-up. There is no hassle of going through the firewall.
run lines inside the cab to the dash for switches.
run fat line to battery from under the truck. other than drilling into the plastic next to the fuse box, i used existing holes everywhere else.
drawback is that you will use a lot of wire.
you're not far from me, so we can set up a weekend day for you to drop by and see the set-up.
4Runner4Leon
Senior Member
Funny timing on your reply - I am smack in the middle of this project, drill in hand, preparing to drill a hole in the firewall for the Daystar grommet. I think that will fit my needs pretty well, even though I don't usually like new holes in the body.
I'd be curious to check out your setup regardless, I'm sure I'll learn something. You say "beach" for your location, which beach?
I'm not sure how it's possible to avoid firewall crossings, unless all your accessories are inside the vehicle. Don't you have to run any switched wires to lights through the firewall?
violation
Member
Funny timing on your reply - I am smack in the middle of this project, drill in hand, preparing to drill a hole in the firewall for the Daystar grommet. I think that will fit my needs pretty well, even though I don't usually like new holes in the body.
I'd be curious to check out your setup regardless, I'm sure I'll learn something. You say "beach" for your location, which beach?
I'm not sure how it's possible to avoid firewall crossings, unless all your accessories are inside the vehicle. Don't you have to run any switched wires to lights through the firewall?
i'm in the south bay as well. hell, why dont you just meet me for lunch today? torrance. i am driving the truck today so you can check out the wiring.
if you need to run wires to the front of the truck, those wires run underneath the truck, thereby avoiding punching through the firewall.
some accessories are inside the vehicle, but i run a few lights to (rear + roof).
wires run inside the scuff plates at the bottom of the door.
violation
Member
big yellow box is fuse box
little yellow box is switch panel on the dash
green lines are (+) wires.
- The roof light is run along the scuff plates, out through the antenna hole in front of the passenger seat, then up the inside of the rubber along the a-pillar. there is about 1.5" of exposed wires on the roof. i tried this route for a fat battery wire but there's just not enough room. however, these wires fit with the antenna wires in there too.
- the camp light is run up the rear hatch.
- the USB plug & volt meter run along the scuff plates, under the dash then to the cigarette lighter area.
dashed purples lines are (+) wires i've installed but are dead ends for now.
black lines are (-) ground wires, short and just find a good ground location nearby.
red lines are (+) wires that all run along the scuff plates, under the dash and to the switch panel.
so yea, lots and lots of wires under the scuff plates.
4Runner4Leon
Senior Member
So I'm finally getting around to doing this project, and wanted to get your feedback on the plan before I go down this path too far.
I honestly think that I managed to use bits and pieces of everyone's ideas on this thread, no small matter. See if you can find where your ideas were noted and implemented.
My plan is to place the 100A circuit breaker in the engine compartment, on the driver side fender:
Everything else will go inside the passenger compartment, to keep it away from heat, dust, and moisture. The wire from the circuit breaker will pass through the Daystar grommet in the firewall.
On the inside of the firewall, below the grommet and to the left of the steering column, I'll have a plate to which I'll mount the Blue Sea 6-fuse box with grounds (left), the 100A relay energized by ACC (upper right), and a Corolla fuse and relay box for the few relays that I might need (lower right):
Here they are mocked up on the piece of cardboard, I'll use 1/4" plexiglass:
Any thoughts/comments/criticism? I'd rather hear it now than after I get all the parts and start slinging wires.
I honestly think that I managed to use bits and pieces of everyone's ideas on this thread, no small matter. See if you can find where your ideas were noted and implemented
.My plan is to place the 100A circuit breaker in the engine compartment, on the driver side fender:
Everything else will go inside the passenger compartment, to keep it away from heat, dust, and moisture. The wire from the circuit breaker will pass through the Daystar grommet in the firewall.
On the inside of the firewall, below the grommet and to the left of the steering column, I'll have a plate to which I'll mount the Blue Sea 6-fuse box with grounds (left), the 100A relay energized by ACC (upper right), and a Corolla fuse and relay box for the few relays that I might need (lower right):
Here they are mocked up on the piece of cardboard, I'll use 1/4" plexiglass:
Any thoughts/comments/criticism? I'd rather hear it now than after I get all the parts and start slinging wires
.
theesotericone
New member
Any thoughts/comments/criticism? I'd rather hear it now than after I get all the parts and start slinging wires
IDK man, I would keep all the big wires in the engine bay. That's the whole point of using the relay. Small trigger wire opens the larger circuit. The less distance between the battery, circuit breaker, relay and Blue Sea box the better IMO.
sleepydad
Senior Member
So I'm finally getting around to doing this project, and wanted to get your feedback on the plan before I go down this path too far.
Any thoughts/comments/criticism? I'd rather hear it now than after I get all the parts and start slinging wires
if you need any extra connections... I have always wondered if one could get the entire non engine wiring harness out intact. spoiler alert, you can.
<a href="https://imgur.com/dyA4JY3"><img src="https://i.imgur.com/dyA4JY3l.jpg" title="source: imgur.com" /></a>
4Runner4Leon
Senior Member
I hear you, and I considered a number of locations for the Blue Sea box. Everything from right above the existing fuse box in the engine bay (like your build), to right next to the driver side fender hinge (sleepydad), to under the rear seat (kolelt), to all the way back in the rear cargo panel (violation).
I'm leaning towards the under dash location because in my case, that's where most of the loads will tie in - seat heaters, mirror heaters, power outlet circuit, etc. So I'll have one big 8 ga wire come through the grommet to the fuse box, but then the individual load circuits will tie right into the box without having to go through the grommet and into the engine bay.
I've always read that you want the fuse box to be closer to your loads, not to your supply. Sort of like why you put a subpanel in a home if you want to have a bunch of breakers in a distant location, and run a big cable from the main panel to the subpanel. So if most of my loads were under the hood, I'd probably mount the fuse box there, but I think mine will mostly be in the passenger compartment.
In the end I think it's a toss up (it's only about a three foot difference in cable length), so provided the cable is sized adequately, it doesn't make a difference. I did think that it'd be nicer to have the fuse box away from heat and moisture, so that's why I'm leaning towards the under dash area.
I do think that I may move the 100A relay into the engine bay, near the circuit breaker. First, I bet that sucker is loud when it clicks (I'll test it tonight), so I don't know if I want that clicking under my feet every time I start the truck. And second, it would mean that the portion of cable in the engine bay from the relay to the fuse box under the dash will not be "live" when the key is off. I don't really see an issue with having a "live" cable (the starter cable is "live" too if you decide to cut through it
), but it does seem like a small benefit, so why not.What do you think?
That's quite the spaghetti of wires! I actually did consider pilfering a newer (99+) harness and fuse box for my '97, thus getting the OEM fog light, heated mirror, and power outlet relays and fuses that mine doesn't have - but in the end decided it's too much of a project. You're obviously braver than me!
I do plan to snag a long section of an OEM harness at the junkyard to have some OEM wires on hand. Just makes the job look cleaner IMO.
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sleepydad
Senior Member
I hear you, and I considered a number of locations for the Blue Sea box. Everything from right above the existing fuse box in the engine bay (like your build), to right next to the driver side fender hinge (sleepydad), to under the rear seat (kolelt), to all the way back to the rear cargo panel (violation).
I'm leaning towards the under dash location because in my case, that's where most of the loads will tie in - seat heaters, mirror heaters, power outlet circuit, etc. So I'll have one big 8 ga wire come through the grommet to the fuse box, but then the individual load circuits will tie right into the box without having to go through the grommet and into the engine bay.
I've always read that you want the fuse box to be closer to your loads, not to your supply. Sort of like why you put a subpanel in a home if you want to have a bunch of breakers in a distant location, and run a big cable from the main panel to the subpanel. So if most of my loads were under the hood, I'd probably mount the fuse box there, but I think mine will mostly be in the passenger compartment.
In the end I think it's a toss up (it's only about a three foot difference in cable length), so provided the cable is sized adequately, it doesn't make a difference. I did think that it'd be nicer to have the fuse box away from heat and moisture, so that's why I'm leaning towards the under dash area.
I do think that I may move the 100A relay into the engine bay, near the circuit breaker. First, I bet that sucker is loud when it clicks (I'll test it tonight), so I don't know if I want that clicking under my feet every time I start the truck. And second, it would mean that the portion of cable in the engine bay from the relay to the fuse box under the dash will not be "live" when the key is off. I don't really see an issue with having a "live" cable (the starter cable is "live" too if you decide to cut through it
What do you think?
That's quite the spaghetti of wires! I actually did consider pilfering a newer (99+) harness and fuse box for my '97, thus getting the OEM fog light, heated mirror, and power outlet relays and fuses that mine doesn't have - but in the end decided it's too much of a project. You're obviously braver than me!
I do plan to snag a long section of an OEM harness at the junkyard to have some OEM wires on hand. Just makes the job look cleaner IMO.
no idea why but now I have a complete intact engine/cabin wire harness from a 99 sport on hand.
if you look at the way Toyota did it, the battery and alternator are very close to the fuse box. then loads go out from fuse box with correctly sized wires. I think that is a good pattern, they seem to know what they are doing. most of their relays are also very close to the fuse box, except the transmission relays and they are scattered around the truck. transmission guys missed the memo.
I have more experience with marine wiring than auto. In marine stuff long runs are more common. fuses have resistance and they are designed to blow so putting them farther away from their source voltage might not be best practice. If you had to design an entire truck system you would take a different path than us crazy owners. putting a fuse right before each load and then having to dig or tear things apart to find the blown fuse, yea not good.
having a one stop location for under the hood and inside the cabin was really my motivation.
your plan looks good to me, it's a pain but it's worth it. future you will thank past you, maybe.
another thing... check out this vid. I learned some things from Weber auto. I'm sub'ed to his channel, he's a great resource.
https://www.youtube.com/watch?v=nELwmfAOz_I
4Runner4Leon
Senior Member
But they also have some fuses and relays under the dash (4WD, ECU, Wiper, Turn, etc). I can't find a pattern for why some are under the dash and others are in the main fuse box under the hood. I see both high and low power circuits in both locations. The ones inside seem to be controlled by ignition switch, but so do some of the ones under the hood
.Great video! Now I have to go and check every fuse I ever installed to make sure they're not the cheapo kind. Weeeee!
4Runner4Leon
Senior Member
I forgot to update the thread once I finished the project, as I often seem to do.
I installed some rivnuts in the inner fender to mount the 100A circuit breaker and 100A relay:
Then attached them with M6 screws:
Everything was connected with 4AWG welding cable - from the battery to the circuit breaker, to the relay, and to the fuse box inside the passenger compartment.
I added the Daystar grommet as recommended by others to provide an opening in the firewall. Below is the grommet with some wires going through, and the mounting brackets I fabricated for the plastic plate on which the BlueSea box and Corolla relay box will be mounted:
Here is how the fuse box and relay box are mounted to the plastic plate:
All the circuits completed:
I installed some rivnuts in the inner fender to mount the 100A circuit breaker and 100A relay:
Then attached them with M6 screws:
Everything was connected with 4AWG welding cable - from the battery to the circuit breaker, to the relay, and to the fuse box inside the passenger compartment.
I added the Daystar grommet as recommended by others to provide an opening in the firewall. Below is the grommet with some wires going through, and the mounting brackets I fabricated for the plastic plate on which the BlueSea box and Corolla relay box will be mounted:
Here is how the fuse box and relay box are mounted to the plastic plate:
All the circuits completed:
