Best Place For Firewall Wiring Passthrough??

skolinsk

skolinsk

New member
Hello all,
I am hard-wiring 2 heated seat pads (driver and passenger seats) to my battery on my 2000 4cyl 4runner. I decided to wire each seat separately complete with its own in-line fuse holder (up to 30a). I've got all the parts (wires, wire connectors, terminal connectors, in line fuses, etc). What I do not know is the best place to pass through the firewall?

Also, when it comes to mounting the negative ground wire, should i put it on the one thats already there from factory installation (right next to my battery). Or mount the ground wire on a different spot? i remember there being other ground spots right next to the factory one under the hood on the perimeter of the engine bay.

Any insight from you guys is greatly appreciated as always.

BEST PLACE FOR FIREWALL WIRING PASSTHROUGH??

thanks again,
sk
 
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i know there's one hole on the drivers side that comes in below the drivers side fuse box, but i was having trouble getting a single 10 gauge wire through there, much less all 4 (2 pos, 2 neg). so i guess i should rephrase my question, is there a better place to wire through the firewall? or a better way to thread these wires through that pass through.
thanks yall
 
I know this is not highly recommended at all and you should not do this but. I made a small slice in the rubber fixture, where all the wires run into the interior to fit my wires through from my fog lights. Then i used a Wire hanger and put hockey tape on one end of it and taped my wires to it and pushed it though the small slice.

Now like ive said before i do not recommend doing this. But if you do BE VERY VERY careful. I took every precaution to make sure i didnt damage anything. After i was finished i sealed the small slice back up with some high heat silicone cocking. Turned out pretty nice.
 
i used a coat hanger, cut it up into a rod, stick it threw the grommet and wrap the wire around then pull back threw..


as far as grounds, you can put it any where with metal on metal contact, because the whole body connects back to the batt.
 
what i usually do is drill a new hole and put a grommet in. The reason why is that when you go through existing grommets, you risk damaging the wiring that currently runs through there, you also often ruin the waterproof-ness of this point, and finally when doing other repairs, you can cause yourself a lot more work. just my 2
 
that is true stick, but im a bit lazy when it comes to that... its an easy solution for me, just stick it in and pull it back...
 
my problem is i modify cars professionally, so i will always do things the best way possible. If you fry a module in a rain storm because water follows some wires down through a torn grommet, and you did it to yourself, all you can do is call yourself an idiot. Now if you have someone else do the work and that happens, that means you get to blame them, and then expect them to fix it! So for me never an option of being lazy, do it the right way once and be done.
 
i can understand that! i can cut corners on my own car because i know how they work. i am a mechanic at a local shop that has been in business for over 25 years, and have seen things when people do it themselves and when worker at the shop mess up! (knock on wood) its not good, looses time and money!

but can you agree with me, how much water gets close to that grommet against the firewall where the main wire harness runs threw? not very much i think
 
shootmymime said:
[B, how much water gets close to that grommet against the firewall where the main wire harness runs threw? not very much i think [/B]
Click to expand...

I agree unless your up to your windows with water you wont have to worry about water getting that close to your wires and fuse box and such.
 
thats assuming the owner never washes an engine bay or lets a detail shop near the vehicle as well. There are multiple ways to to get the engine bays wet other than just off road fun. Other things besides water are (if the grommet gets really cut up) dirt and cold air in the winter and hot air in the summer.
 
ok guys, did it all up today. worked out pretty well i think. threaded the wires throught the drivers side, up each kick panel and underneath each seat respectively. both seem to work with 20 amp fuses in place (although i am trying to find the lowest fuse that will power them but not break). looks good, and im pretty happy with it overall.

i decided tohardwire them because they kept blowing out the power accessory fuse when i had them running on the factory cig lighter.

as for making sure power is cut off when the engine is off... that would be my only improvement. its true (im pretty sure) that they are still fed power if they are not actually turned 'off' on the heat seat switch...i would consider having them tied to the engine, but i would ask if this is there a similar setup to what i have now or is it a hole new project?? ideas?
 
you should be using a relay for this .... standard 30amp automotive relay will work, check either car audio shop, or auto parts store.

Wire like this:

Terminal 87: To Fuse at Battery

Terminal 30: To seat heater

Terminal 85: Ground

Terminal 86: Turn on lead, take this to your cig lighter wire. or any ignition wire.

You won't blow fuses this way since the ignition wire will only be powering the relay, and the seats will still be powered off of the battery directly.
 
ok, i like the sound of the relay. few questions though;
can i hook up both seats to the relay or one relay per seat??

second, what line do i tie the relay to?? an ignition wire you say? do i just connect it to some existing wire or redirect it?? can you be a lil more specific.. im not to good with this stuff to be honest

and lastly the placement of the relay(s).. in cabin or in engine bay, but i guess thats dependent on the other 2 questions as well..

anyways, thanks guys.. ilook forward to reading your answers
 
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ok, so i think it will be worth my time (and battery consumption) to install a relay for these seats. I am considering just putting them in under the hood. I hope theres no problem here, as long as there out of the way. The only thing that might be of interest here is that I am in Vermont=COLD.

either way, the only thing im not sure about is if i need 2 relays, since i wired up each seat to its own in-line fuse. (im assuming a 30a relay will be the proper match for the 30a rated in line fuse on each setup.. even though its currently running on 15a fuse)..

Second, what do i want to be my "switch" input. keep in mind that if i do this under the hood, i'd like it to be something close, IE something under the hood near battery... either in the fusebox or somewhere under accessible the hood.

Again, thanks for your help in advance
sK
 
wired it to the cigarette lighter from under the hood. i just kinda wrapped it around the positive lead from the back of the right 12v jack. its a bit sketchy i gotta admit.. but i didnt wanna F&*(^ anything up. i figure it can only start a fire while im in the car.. and i like those odds.

sk

thanks again for the help fellas
 
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