Ken the electrical guy Q n A

Got a quick question for you,
What's the best place online to buy good quality wire and connectors?

 

I use Prowire.com alot

 

Awesome, thank you.

Follow up question. Can you point me to some reading material about different wire types, their applications, and best place to use them? (GXL vs SXL vs GPT)

I'm wiring up a dual battery system with 6 switch accessories, 4 full time on accessories with wiring running to every corner of the truck. My wife and are are preparing for a 3 year pan american trip and I'd like to do the best quality work.

 

So I just wrote you a 3 page response and my web browser glitched and i lost everything. Tell me more about your project. What are you powering? where are you mounting your secondary battery? how are you going to isolate them? are you going to utilize solar? What are you powering, switched and constant.

by the time you reply I'll have gotten over my temper tantrum and I can try again lol

 

You can definitely accomplish what you are trying to do with a relay and the switch you linked above.

Mount your switch in the desired location:
Mount your relay in its desired location:

You'll want to find two wires

1) to tap for keyed on switch input
2) to tap for illumination.

You'll want to grab key on power from a cigarette lighter or other keyed on source. It's really not going to matter because you'll only be adding about 0.2 Amps to the circuit.

When I say illumination. I mean this how the led lights inside the switch will be turned on. Some people like the led to turn on when the head lights turn on. Other like it when the switch input has power. It's really up to you. Considering you have a two led switch I would suggest the upper led get power from the switch output do when the switch is on the light illuminates indicating its on. The lower light I personally have mine turn on when the running/headlights are on. As I said before it's completely up to you.

Now that you have found you keyed on switch input wire and illumination go out and disconnect the battery.

Using a wire tap, making Y or T with some wire and connectors, or soldering you'll want to be able to attach a wire going to your switch from your keyed on source. Wire taps are the easiest but least reliable. If you instal' it and wrap it tight with electrical tape or high ratio heat shrink it'll be ok.
[PRO TIP: Verify your wire tap is functioning nominally and wiggle it around and test with a volt/multimeter before you tape/ heat shrink it].

Keyed on should go to input side of the switch.

switch output should run to your relay position 85 and the upper lead positive terminal

the lower LED positive terminal will connect which ever circuit that "behaves" that way you want. If you want it to light up along with the running/headlights you can grab that from another switch inside the dash. Just remove the connector/switch from the dash and tap off it.

the ground on the back of the switch can go to some bolt in the dash or any sheet metal. Id stay away from self tappers if I were you. try to find a bolt and crimp a ring connector.

The switch is now wired.

Cut the yellow wire that the article you linked called out. Cut it away from the connector you'll want the extra length to work with.

One end goes to 30 and the other 87a. At this point you may or may not want to add a fuse here. I don't have the wiring diagram for that circuit in front of me and I'm not sure of its design. I always like to error on the side of safety. If I was going into this situation "blind" having no idea of the circuits design but trying to do the mod. I'd probably put a inline fuse on the 30 side of the relay. Then Id put the smallest fuse I could find in it. It'll probably blow based off the size of wire I see in the pic. Then Id go up to the next size until they stopped blowing. That way I feel like If something happened it'll at least be protected from the new wires shorting somehow. In reality you really should research what the circuit draws and size the fuse appropriately. That being said most of us won't do that so I try to take that into consideration.

86 will go to ground.

In this configuration when you hit the switch the circuit is broken and it be as if the wire was unplugged. When you turned the switch off it would function as it would before the mod.

boom your done

p.s.

if you need help on how to find which wire is the keyed on power and the "illumination" circuit lemme know I can help explain that

 

yes, pretty much all of the above - I want to power lights, water pump, heater, some 12v ports, possibly an inverter through a

$25 Nilight 90101E 5Gang Multi-Function 5 Gang Rocker Dual USB Charger + Digital Volmeter +12V Outlet Pre-Wired Switch Panel with Circuit Breakers for RV Car Boat Truck Trailer,2 Years Warranty,Blue

switch like one of these. And also have it able to switch On accessories when the truck's off.
I have a dual battery setup, they're both in the front of the truck under the hood and wanted something closer rather than running long wires all the way back to the front.
thanks!

 

Ok Gotcha,

So if I was you this is what I would do.

Id look up everything that I was going to power from that panel. Id go online and look up the specs and it should give you the draw (amps) or wattage (volts x amps).
add them all together and that would be my minimum load considering you had it all on simultaneously. Even though you may not ever have them all on at the same time I build my system as if I would.

Once you have that Id multiply by 25-50% so if I wanted to add more down the road I have plenty of "space".

Now with this new number (Total calculated load @ 12v + (50% total calculated load @ 12v). well call this Load Net

I would measure from the battery I'm going to power my accessories off of to the switch panel. Then using the chart I attached I would find the appropriate size for the run I'm going to have.

Then I would find a service/power switch that met or exceeded my Load Net calculation. [Important! A lot of companies advertise their switches max load capacity, not their continuous. Net load needs to meet or exceed continuous rating ]

Assuming your dual battery has a isolator/ACR set up.

I would then mount all of my accessories in the places that they will go. I can then decide how I'm going to route my wires and measure the distances taking into account for corners, having to go under and over things, etc...

I would record all of my measurements as I'll need them for harness construction later.

Now I would build my harness(s) for each or all of my accessories. You can build multiple harnesses for each accessory or one big one with branches that go to each accessory. This will depend on your situation and what makes the most sense.

after I got all of the harness/sub harness wired,loomed, and heat shrunk, I would start tucking/stuff/hiding/mounting/clamping them in place all the way back to my switch panel location.

I would do my final mount of switch panel, install my master switch, mount any relays or any other components. I would run my circuits to my switch panel and make a service loop here. The idea here is you should be able to remove you panel easily without disconnecting anything. If you have to fight to get behind your switch panel its too tight. Another benefit of the service loop is if its done correctly can act as a drip point in the case that the loom gets water inside of or on it. The service loop should be made in such a way that it water would run down to the bottom and have to run upward against gravity in order to get to the switch where it plug in.

I would hook it all up, test, and trouble shoot any issues.

how and when the switches work is a matter of where they get their power from and what load they will carry. If they are energizing a relay the input can be basically anything. If its a load carry switch then it'll need a fuse. If this part is confusing or you have questions please let me know I'll be happy to go over switch design, fusing, and relaying.

-Kenny

 

Typing on my phone so parden the mistakes.
System meant for long term travel. Full time
overlanding for 2-4 years. wife and I are doing the pan american at a slow pace. I want everything to be A+ quality. Down to the last little wire and connectors.

Systems set up:
Off grid engineering split battery system
northstar group 35 battery for 2nd batt
Redarc BCDC 1225D
Switchpros 9100
Blue sea 6 circuit fuse block
Power trays for cable management

Starting battery running:
-Winch independent
-Switchpros controlling(ignition controlled)
DD SSC2 pro ditch
Viair compressor (via relay- hard mounted in bed)
(6) KC cyclone rock lights (used for camp lighting)
TDB light bar in bumper
2 Ridged scene lights

House battery-passanger side engine bay--constant
Dometic CFX55IM(in cab)
Camp lights-3 national luna touch lights
2-12v outlets inside tent(used to run cpap 1.09amp draw and fan)
Small water pump and UV filtration unit. (In cab)

Solar- 100w solar on the roof.-permanently wired.

The two biggest issues I'm running into is what types of wire to run (not size, I got that figured out)
And what the best connectors are to use, I need to be able to disconnect everything in the tent and everything on the roof rack (solar). Are Anderson plugs good enough?

Other minor issues
-- decent dual battery level monitor that has to be cheaper than the $200 redarc one.
--best location for disconnects to isolate everything for water crossings.

 

Looks like you have a great foundation and quality products to work with.

I would start by moving anything that will be ran while the truck is not running to the house battery. Also If you are going to be spending three years on the road I would consider either bumping up your house battery bank and or doubling your solar. I know these aren't cheap upgrades but based off your electrical loads, assuming you'd like to stay in an area without driving for a few days or so. I think you'd really like the extra reserve capacity. I would recommend having a removable solar panel mounted to the vehicle. Also have an extension harness for that panel in the turck so if you are in an area where you would really like the truck in the shade, but need the solar you can have both. Lithium batteries are a great option and will soon be replacing most Lead Acid/AGM batteries in the near future as the primary house battery unit. They are expensive so you'll have to cross cost vs space vs reserve capacity. It would just be nice for you to be able have the electrical capacity to add something you find on the road and or need while ur out there. Without modifying your foundation of course.

I personally run 200 watts of solar with 1 battery and I'm tip top. I also don't have as many accessories as you do.

When it comes to wire for most automotive situations and camping rigs any standard "primary" wire will work.

There are so many different styles,specifications, and manufactures out there that knowing everyone is kind of a waste IMO.

I use TXL or better for anything connected with a ECU/PCM, Sensor, CAN /communications, etc...

Welding cable is a great price vs quality for high current large gauge situations. You can use this for almost all of your large distribution needs. However, For the starter cable I prefer thick wall high heat starter cable. If it's close to the exhaust headers i'll also sleeve it or wrap it with 2000
F wrap. Cooper does not like to heat cycle a lot. Extreme heat cycles will cause it to work harden and become brittle.

For all of your 12-20 gauge needs that aren't mentioned above you can basically use any stranded copper wire you find on Amazon. Stay away from copper clad / aluminum. Copper only.

The only time you really need to start worrying about what type of wire you use is when you get into high heat situations, racing situation where weight is critical, high level automotive wiring where everything must be aesthetically perfect, and sensitive communicating circuits. If it's stranded copper you're good bud don't over complicate it.

I will say that I do run into certain situations where I need a specific specification of wire. In that situation I will refer to google and manufactures for a conductor that will work. Like i said above though its very rare and it's because I'm doing something super trick or odd.

Here's a little to short read about different metals and their use as electrical conductors
https://www.calmont.com/resources/types-of-conductors/


https://www.lapptannehill.com/what-are-the-differences-between-the-types-of-primary-automotive-wires
Here's another link that goes over different primary wires.

 

Yeah part of the reason I went with the red arc BCDC was the ability to change batteries and upgrade the lithium if needed. I also have room on the roof rack for an additional hundred watts of solar.
I'm still in the process of installing most of the stuff. My wife and I are going to test run it over the next two year before we leave.

I appreciate the advice on the type of wiring. Sounds like I don't need to be as picky as I'm thinking I do.

Any recommendations for a good dual battery voltmeter that's cheaper than the $200 redarc one?
I don't mind spending a decent amount of money on it but the red arc one seems like the overkill.

 

If your looking to just motor the voltage of each battery bank just grab one off Amazon. Doesn’t need to be super fancy.

 

Hi Ken!

I have some questions related to the yellow Wire mod in my 2010 dc sr5.

from my understanding I need to cut the 9-pc wire (yellow/black) behind the glovebox, then tap it into a +12 wire.

here is my thread post with more details:
https://www.tacomaworld.com/threads/yellow-wire-mod-12v-tap.697291/

The thing is...I don’t know which wire is 12v and ignition activated, nor which 100ohm resistor to buy for placing between yellow/black wire (9-PC) and the 12v.

is this something you can help with??

 

Hey @ardrummer292 check this out...

Hey dude, Yeah I can help you out

So you have two options. You can use a relay with on off switch or a On-ON SPDT switch. Depending on the switch you would like to use either will work the same.

If you want to use the on off switch you'll wire it like this.

Relay
85=ground

86= 12v+ output from switch

30= Section of yellow/black wire heading to TRAC ECU "yellow wire"

87a= Section of yellow/black wire heading to transfer case "yellow wire"

87= 12v+ and resistor

Personally, I might suggest creating a "fresh" 12V circuit for this. When it comes to modifying circuits that are tied into the engine/drivetrain computers I really don't like taking chances as far as possible noise invasion into the circuit. I'm probably paranoid but I feel like it's better to be safe than sorry. Use an add a fuse at the battery and make a new 12v+ source for this.

Switch.

Input- Key on 12v+
output- 87 on relay

You can wire in the resistor a few different ways.

1) You can use non insulated crimp connectors and crimp it then heat shrink it with some heavy duty heat shrink

2) You can solder it to the wire and then heat shrink it

3) you can buy a relay holder/mount and wrap one end around the philips screw terminal and either crimp or solder the other end to the wire.


The SPDT switch is

Common input=Section of yellow/black wire heading to TRAC ECU "yellow wire"

Output low=Section of yellow/black wire heading to transfer case "yellow wire"

Output High=12v+ and resistor

Illumination will be up to you.


You can get the resistor off Amazon.

You'll need to buy a volt meter and or power probe. If you want to know which circuits are key on, constant, ground, or any other information you may want to know about anything electrical in your vehicle.

 

Holy smokes you’re the man @Kens04Taco

Many thanks for the thorough insight! I feel 10 steps closer to my objective.

I will absolutely run a separate 12v..biggest concern was tapping in and screwing something up and without 12v this version of the mod won’t work. Want the TRAC in 4lo but not blinking light or transmission shift side effects of the ywm v1.

Also...just curious..have you ever done this mod yourself or do you just know these trucks like the back of your hand?

 

no problem bud. I don’t own a second gen but I do own a first gen. I also work as custom electrical system designer and car builder.

This stuff
Isn’t Tacoma specific it’s all information that applies to all modern vehicles.

I haven’t done the mod but going off the link you sent me I wouldn’t have an issue doing it for a customer either way I described above. I personally would download the wiring schematic before I did the work because when it comes to my customers I don’t guess. I’m a professional so they get my best. But if it was my personal vehicle I’d do what I said above and send it without thinking twice.

 

@Kens04Taco, thanks for the highly informative replies. I really need some more coffee before I try to decipher what it all means.

Your comment about adding noise to the circuit definitely piqued my interest. I am concerned that the TRAC ECU "yellow wire" carries a digital signal, which I would assume to be highly susceptible to corruption from EMI. Since relays are electromagnetically operated, I can only assume that serious issues are a very real possibility when introducing one to a digital circuit (which the TRAC ECU "yellow wire" may be). I imagine this can be "designed around" by only energizing the relay when breaking the circuit, minimizing the potential of signal corruption when in an operating (closed circuit) state.

Either that, or I'm massively overthinking this whole thing and need to chug a couple beers and just do it.

 

I think as long as the skid control ecu receives an ignition activated +12v via the yellow/black cut from 9-PC this will be a seamless effort. Based on @Kens04Taco responses that should be supplied from a fresh circuit added to the fuse box. With an 09-11 I don’t think a switch is required since 4h standard is equal to TRAC OFF 4h in 2012-2015 but would allow the mod to be toggled at will.

The details of that process aside...this mod is simply blocking the skid control ecu from knowing when we switch from 4hi to 4lo, while allowing 4wd ecu to still communicate hi/lo switch to 1. Stop blinking light issue with 4lo indicator and 2. Allow 4wd ecu to inform ECM adopt proper shift pattern in 4lo.

neither of these were possible on the initial version of this mod (cut PA21)

@Kens04Taco: can you confirm if a switch is needed for the 12v since the goal is to always send a +12v to the skid control ecu while the truck is running?

If it isn’t. Steps should be:
-Unhook battery
-Cut 9-pc
-Install dedicated 12v wire via new circuit
-Connect the new 12v to y/b wire 9-pc that connects to skid control ecu
-Reconnect battery
-Turn on truck
-have TRAC in 4lo

if I’m wrong or spewing fake news please tell me

 

Most things that communicate with the ECU are going to transmit an digital or analog signal. This is the message that gives the ecu its information. Wether that information. Is yes or no. How fast are we going from yes to no. How long are we on yes compared to no, and where are we along the way from no to yes.

something important to note. In the mod the resistor is an important piece because the wire is communicating with the ecu. The resistor is being used to “pull up” the voltage from zero. ECU read 0v as undefined and they don’t know what to do with it. An error (value outside of it’s preprogrammed range of values) is observed and a code will then be generated and the check engine light will turn on.

Modern ECu and control circuits can be complex in design at times and as I mentioned before I’m basing my suggestion off of the links that were added to the thread. I’ve never done the mod. I’m just taking the authors words that it works and nothing happens lol

If I had a second gen in front of me it would be different but I don’t. I’m still rocking out like it’s 2004 .


My suggestion about making a fresh 12V+ Input source was a way for me to feel that the input going into the ecu would be clean meaning not infested with electrical noise (distorting the message i mentioned about). Considering you are talking about a component that controls when the truck shifts this could potentially be dangerous.
How the computer interprets and uses this message may have a failsafe but without knowing we'll error on the safe side.

If you were to grab 12V+ from somewhere inside the cab who’s
To say you or the previous owner of your truck didn’t tap this or “grab” power here. I can’t be sure so if you make a new 12V+I feel like we’d be ok. Unless you ran it alongside a high load carrying wire or a particularly noisey circuit which are both doubtful considering your factory harnesses should be intact and functioning.


So look that’s a lot of words and electrical non sense lol.

You want the switch because
you want the ability for the system to function as it was intended during normal operation. Then "hack" it when you want to crawl out or over something. Just like you would treat a locker.

 

I can't speculate on this because I'm not familiar with the TRAC System and its electrical or mechanical design. I'm currently building a 34 Ford Victoria using Tesla parts so I'm at about maximum learning capacity with that lol. Maybe when If I make the jump to 2nd or 3rd Gen i'll look into it more closely.

If it was me and I wasnt sure Id run the switch just in case something happened and got weird I could always go back to factory circuit design.

 

I need to take another look at the yellow wire mod thread. I don’t recall seeing anything about a resistor, only guys yanking the yellow wire out of the connector and taping up the loose end.