To switch or not to switch...

Hey team!

Last Sept, I decided to add an 8 inch LED to my bull-bar mainly for the aesthetic aspect of it. When I did that some mistakes were made that cost me plenty but I also learned a valuable lesson. During the illuminated switch (from AOB) installation/wiring portion, I allowed my 12V interior lighting feed to cross over to the 'Dimmer dial (rheostat)' Gnd circuit. This was because I was unsure of the new switch wiring color code; it's different on the "slee off-road" brand. Though it was only for a split second and didn't even blow the courtesy circuit fuse, it was all it took to cause major problems. A few days later, I was seeing the 'ABS' light come on 'momentarily', and then go out.

Next it was the '4low' lamp doing the same thing. Eventually almost ALL of the different (unrelated) warning system lights were showing up (intermittently), including the airbag, steering, skid, TRAC, compass, econo... etc. So I spent a substantial amount of time with the electrical systems manual learning where all of those warning system signals were coming from. It turned out to be my 'Main body ECU'; which manages the interior lighting system, dashboard courtesy lamps and instrument cluster.

FST FWD: ...Since then, I've had a number of 'Hands-on' forum members (very capable guys) P.M. me, requesting assistance with dash lights that went out during an illuminated switch install, but failed to come back on; there were a lot us that participated in the A.O.B. Group buy several months back ("Not saying that this had anything to do with the A.O.B switches themselves"). My point: If you happen to be doing a 'Factory style switch' install and you're going to use the inst cluster circuit to feed the illuminated LED icon on the face of your new switch, 'DO NOT' allow the 12V (HOT) to go ANYWHERE NEAR the "Dimmer dial" ground side; that circuit goes directly to the "Instrument cluster & main body ECU!

PS: If by chance you are already having trouble w/ your courtesy lighting 'dimmer circuit' or you're getting False system warnings; which aren't stored as DTC logs, and think the trouble may be 'MB ECU' or instrument cluster related, here are those part numbers/prices (2010-2015):

'Main Body ECU' (aka-Multiplex Body compu)#89220-35021 $476.00

'Instrument Clust.'(2010-2013... '14 and '15 speedos are different) Toyota 4Runn #83800-35N01-RP $900.00

"These prices are from Toyota dealerships that sell on EBAY so shop around; you could pay as much as double these prices if you buy locally!" Rgds

This is excellent information. Any chance you are willing to help explain how to properly wire these switches in, or do you not want to be responsible to someone screwing something up, because that would be completely understandable.

Thanks for the info. I get very deflated when electrical install does not work properly.

When it's time for me to add switches I am going this route.
Group Buy: Trail Toys NSA Switch Panel - Tacoma World Forums

tigger said:

This is excellent information. Any chance you are willing to help explain how to properly wire these switches in, or do you not want to be responsible to someone screwing something up, because that would be completely understandable.

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It's very simple. Just splice into the illumination wire feeding one of the existing switches. I can't remember the color but it is easy to identify with a meter... Just make sure you see + on the meter as you flip the lights on...

You should be able to use this one wire to illuminate all the switches you would ever have (the amp draw is extremely low).

OUCH, this sounds really expensive to fix. I never bothered to wire up the light activator wire on my switches, I guess thats a good thing at this point. Maybe Im missing something but this sounds like a very easy thing to damage for a $25 switch install?

Man this sounds like an expensive and easy mistake to make. I will be making a custom harness soon for all my lights and other add-ons. I will definitely use extra caution here!!
Thanks for the heads up!!

tigger said:

"This is excellent information. Any chance you are willing to help explain how to properly wire these switches in, or do you not want to be responsible to someone screwing something up, because that would be completely understandable."

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Hi tigger,

I don't mean to imply that these 'factory style' buttons are problematic or particularly difficult to install. It's just that I'm starting to see a pattern of folks making the very same mistake that I made myself. Now because I understand why I made that mistake, I see how easy it is for others to do the same and so I thought it important to discuss it BEFORE anyone else gets blindsided.

This same rule that we must follow regarding the implementing of these switches, applies to the installation of any switch in general be it 12V, 24V, 120V, 208/230, 460 or 480V... Never wire a switch across an electrical circuit (or POS to NEG), it gets wired "IN-LINE" ...always!

NOTE: What I did wrong was to trust the A.O.B harness wiring color code/assignment that I looked up online (some are 'apparently' different than others), and so accidentally assigned the switch contacts across the courtesy illumination circuit; which is how I surged the instrument cluster/Main body ECU; and because I know that others are doing the very same thing, I thought it important enough to create an awareness or else it will keep happening.

So... in answer to your original question: Carefully identify and separate your two switch contact wires and Prove them with a multimeter!. Now identify the illum. circuit; These two must be confirmed with a 12V battery because there's a diode in there and so only allows the current to flow in one direction. So if you connect these two wires across the truck's battery and nothing happens, reverse the two wires and it should light up. If it still doesn't turn on then there's a different problem.

Some harnesses have five wires but the middle wire is a spare (goes nowhere). Tap into whichever stock button on the dash is easiest to get to... I chose the RSCA (restraint system curtain airbag). The Green wire is the courtesy lighting circuit (HOT), which connects to your parking lights. The Gray wire connects to the GND junction and ultimately the 'Dimmer dial' or rheostat. Be particularly careful NOT to hit this wire with 12V... or else lol!

Cheers!

So what I gather here is that you referenced an incorrect wire schematic and connected a hot wire to a ground and caused the damage when activating the switch?

tigger said:

"This is excellent information. Any chance you are willing to help explain how to properly wire these switches in..."

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I'm sorry tigger, 'my bad',

Because you asked the question I assumed that you already know how to remove the driverside "lower airbag knee bolster panel", 'again this is my fault'.

First, using a flathead screwdriver, lift the plastic door-sill (you may want to wrap the tip w/vinyl electrical tape to prevent scratching the paint). Next, slide the "Kick panel" to the right; no need to remove it all the way to get at the 10mm screwhead behind it, so remove the screw. Then using a "Trim panel removal tool" (cost $5 bucks) pictured below:


...gently slide the flat surface of the tip underneath the leftside 'Temperature control trim panel'; not too sure if the SR5/Trail's have the very same trim as the limited.

Now look down at the panel that you're removing and locate a small rectangle insert on it's lower rightside. Insert a small tip screwdriver at it's edge and gently pry it open and you'll see another 10mm screwhead there, remove it and the lower bolster panel will be ready to come off. You'll need to grab it from underneath and pull straight back (gently so none of the clips break). Continue pulling back and work your way up the panel until all of the clips have been released. The trim panel just above this one (where the Inst clust. dimmer dial and sideview mirror controls are), can now be removed as well by pulling it away from the dash; should you decide to add your new switch to that panel's blank-off.

The blank-offs are held in by two clips in back. Just squeeze them and push the blank-off out... your new switches will slide right in and latch. Hope this helps you approach some of the Unknowns of this job with confidence! Rgds

Jhalko said:

So what I gather here is that you referenced an incorrect wire schematic and connected a hot wire to a ground and caused the damage when activating the switch?

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That's exactly right, and I suspect that some others have done the same. There are a few different wiring diagrams online but I don't remember which are bad and which are correct; I wish that I had caught that when I did the install but by the time that I found out about the flaw, the damage had already been done in the weeks prior! If I see it again I'll post it here... the main thing to remember is to Double-check 'your own work' with a meter and battery so there's no room for error!

That really blows Greg :boltsorry, couldn’t resist buddy). Unfortunate it was a costly repair, but glad you were able to get the problem resolved. Glad you shared your experience so others could be aware of the potential issues caused by back feeding an ECU, most wouldn’t so kudos to you. Modern vehicle are very sophisticated and complicated, containing multiple computers, modules, Multiplex / Can-Bus wiring, one misstep can prove costly.

I too have received several PM’s asking about illumination interfaces, in my case (2012 SR5) green wire is positive (+) when parking lights/headlights are turned on, gray wire is illumination ground (-). Gray wire controls light dimming function. These wires can be found at any switch that illuminates when you turn on your lights, again in my case, there was an unused harness (with white plug) behind dash panel that I tapped into. Always test wires with a multimeter before interfaced to insure they a correct as different year Runner’s or different trim levels may differ in color.

Both Slee and AOB switches are low amperage switches (3 amp max), meaning you must install a relay to control whatever component you want to turn on/off. Switch is basically a trigger, load is handled through relay (generally rated around 30/40 amps). Illumination portion of switch are LED, which means they only draw milliamps when energized, so they will not overrate the factory system. Keep in mind if you’re adding lots of switches and additional dash lighting, measure draw prior to installation as you may need to add a relay, factory wire is trigger, relay handles load.

To those of you who have limited 12 volt experience might I offer a few suggestions? Have a plan on what you want to add to your vehicle especially when it comes to wiring, fewer connections are better’er. Review all wiring diagrams and/or schematics, if you don’t understand or are confused on what needs to be done, stop, seek help or pay to have it done. Plan how you will run your wires, if routing through the firewall, try to use factory grommets whenever possible, once wire(s) pass through grommet seal with silicone. Don’t push grommet to the side then run wire between edge of grommet and metal firewall, causing wire insulation to rub on metal edge cutting insulation causing a short circuit. If none are available, drill a hole in firewall and add a grommet, rubber or plastic are acceptable. All external wire connections should be waterproof! When installing ground wires, ensure metal to metal contact, remove any paint that may between connector and metal surface, use a nut and bolt whenever possible, then coat with a sealant like undercoating. Most electrical issues are caused by loose or corroded connections. Encase all wires in wire loom to protect them from possible chaffing or cutting on sharp metal edges. Route all wires away from moving components or heat sources. Fuse all power wires to prevent an electrical fire! When cutting wires to length, cut longer then you need, I like to use the analogy “measure twice, cut once”, better too long then too short.

Verify switch wires and factory wires are correct before interfacing. When making wire connections, I prefer to use solder and heat shrink or high quality electrical tape (3M Super 88), butt connectors can also be used, but require cutting of factory wires. T-Tap’s are the worst type of connection, yes they are quick and easy to use, but they cut the wire when crimping and over time will cause intermittent connection issues. Route wires to connection point, make connection, protect connections, and then test for correct operation. Once verified, protect harness with wire loom, nothing worse than opening up a dash only to find wires running everywhere “wire spaghetti”. If done correctly, the only failure should be because the item you added failed, not you’re wiring. Reassemble and enjoy years of operation.

Here are schematics for both switches...................
Slee
View attachment Slee Wiring Diagram.pdf
AOB
View attachment AOB-SW800 Wiring Diagram.pdf

I have multiple AOB and one slee switch, the aob were ordered at different times and had two different wiring sheets, since Im electrically challenged I studied for awhile before install. Still blew a fuse on my power wire since I have ridiculously large hands that slipped while testing. Glad for the info here, I was planning to connect that last light wire sooner or later.

barryhiram said:

That really blows Greg :boltsorry, couldn’t resist buddy).

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Hi Barry,

Very nice write-up pal, wish I'd said it that way, that was GREAT!! :hatsoff:

...(show-off!) :spam2:

rigtec said:

Hi Barry,

Very nice write-up pal, wish I'd said it that way, that was GREAT!! :hatsoff:

...(show-off!) :spam2:

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Ha-ha-ha, thanks man. Been awhile, hope you've been well.

...(show-off!) :spam2:

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:ban: me

rigtec said:

"...Now look down at the panel that you're removing and locate a small rectangle insert on it's lower rightside. Insert a small tip screwdriver at it's edge and gently pry it open and you'll see another 10mm screwhead there, remove it and the lower bolster panel will ready to come off. You'll need to grab it from underneath and pull straight back (gently so none of the clips break). Continue pulling back and work your way up the panel until all of the clips have been released..."

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Because I realize that we have some members here that aren't yet familiar with removing any parts from their trucks; much less parts from the interior and dash (some of you folks are AMAZING with what you do w/ your rigs... ), I thought that these photos may serve to assist in the removal of the 'Lower airbag knee bolster panel' as mentioned in an earlier post, "See below":


The first photo (above) is to show the two mounting screw holes at the lower left and right of the panel; the one on the right has a 'Hinged plastic insert' to cover it, just use a miniature flat tip screwdriver to pry it open.



This photo should help to illustrate the location of all of the Pink and white push clips arranged throughout the backside of this panel... and again you see the two mounting screw holes at the lower left and right... to reinstall this panel, line it up w/ the dash, push in and tap; you should hear it snap in. Then replace the two 10mm screws and that portion is done. Replace the "Temperature control trim panel by lining-up and tap in. Now slide the leftside 'kick-panel' back in place, and then re-install the door sill by lining it up and tapping it down w/ your hand... DONE!
:cheers:

Hi folks,

If by chance anyone is having a problem with your Main Body ECU Multi-plex Network, shoot me a PM, I may be able to help you with a spare that I have, "Brand new (un-used) still in-box from Toyota". 'Main Body ECU' (aka-Multiplex Body compu)#89220-35021

Cheers!

Hi [MENTION=68685]Ducmonsta[/MENTION],

I was hoping you would voice your concerns 'on this thread' since it addresses the issue(s) that created this trouble and so others might observe some precautions. Back in Dec '14, I purchased a new 'Main Body ECU Multiplex Net' to get this repaired but the installation of this part was delayed, due to the EXTREME winter we've had here in NJ. Waiting created a great deal of anxiety for me because I really needed to get this depressing chapter behind me. But (as it turns out), the 'Patience did have her virtue'... During that time waiting, the trouble with the 'MBECU' ...Has disappeared! That's right... All of the quirky dropping out of the Speed-o-meter, Tach-o-meter, Instrument Cluster and 20 other warning light prompts just went away as if it had never happened.

I've taken most of the dash apart to learn what could have happened but I didn't see anything obvious like broken, uninsulated wiring or potentially shorting circuitry, and everything works. So to reiterate, I do know how/when I created this problem... I just don't know how/why it went away (Quite mysterious). Now it's been about three months (that's longer than the problem persisted) and things 'seem to be' back to normal. And now I still have a brand new MBECU which I paid nearly $500 bucks to get, and it's in the closet... "So I guess we'll see."
:couch2: Best to you!

Rgds

My concerns actually have nothing to do with switches. I was mainly concerned with your alternator upgrade causing issues with your electrical system (other thread).

My dual battery system has been acting up so I was considering putting a upgraded alternator in my system. I didn't realize that your problem was the installation of aftermarket switches.

I bet that correcting that situation is why you are no longer experiencing the christmas light dash symptoms. It was probably a small enough voltage trigger that caused the lights to come on and not be significant enough to actually damage your ECU. It's too bad that electrical components are non-returnable for most companies/dealers.

In my situation, I've had a constant 2 amp draw on my accy battery and while it recharged while running, the factory alternator never got it back up to spec. So for the past 2 years of constant draw, recharge, draw, recharge, finally took it's toll on my aux battery. I've spent the past several weeks leaving the aux battery disconnected and charging on a wall type system at .2 amps. It gets the battery up to spec but as soon as I have a load on it, it drops to 10v. I'm glad it's not the main battery and I can actually still use it to run all the accys while the truck is on. I just can't run my 40" Rigid or ARB dual compressor or strobes with the truck off. So, it's not a big deal and I'll eventually replace that battery.

Ducmonsta said:

My concerns actually have nothing to do with switches. I was mainly concerned with your alternator upgrade causing issues with your electrical system (other thread).

My dual battery system has been acting up so I was considering putting a upgraded alternator in my system. I didn't realize that your problem was the installation of aftermarket switches.

I bet that correcting that situation is why you are no longer experiencing the christmas light dash symptoms. It was probably a small enough voltage trigger that caused the lights to come on and not be significant enough to actually damage your ECU. It's too bad that electrical components are non-returnable for most companies/dealers.

In my situation, I've had a constant 2 amp draw on my accy battery and while it recharged while running, the factory alternator never got it back up to spec. So for the past 2 years of constant draw, recharge, draw, recharge, finally took it's toll on my aux battery. I've spent the past several weeks leaving the aux battery disconnected and charging on a wall type system at .2 amps. It gets the battery up to spec but as soon as I have a load on it, it drops to 10v. I'm glad it's not the main battery and I can actually still use it to run all the accys while the truck is on. I just can't run my 40" Rigid or ARB dual compressor or strobes with the truck off. So, it's not a big deal and I'll eventually replace that battery.

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Bobby, My alternator won't keep my 27 group dual purpose battery fully charged either- especially when I run my ARB fridge 24/7. Even after a long trip it won't be 100%. I never have a problem starting the truck, just bothers me that it can't top off the battery fully. I know it's not designed to do this so no surprise really.
I picked up a small battery maintainer with a harness/plug that stays attached to the battery. I just plug it up about once per month and it brings the battery up to 100% overnight. Kind of a pain but it works...

BTW- Constant draw shouldn't be an issue for those deep cycles if they are maintained. I regularly discharge my trolling motor battery on my boat (same deep cycle 27 group) to below 50% and it has been going strong for 6 years now. I have an onboard charger that keeps it healthy between weekly fishing trips.

Just my experiences!