Here's an AIM conversation I just had with lecchilo. I'm posting it so if anyone finds this thread later on with a similar question, it'll help clarify the issue further.
lecchilo (1:22:32 AM): i wanted to ask you a couple more questions about the sims
komodo (1:22:42 AM): go for it
lecchilo (1:22:43 AM): cuz i'm planning on getting the one you had and returning the AA ones
komodo (1:23:11 AM): sure thing, however I did buy my sims almost a year ago, so it might not be a bad idea to contact Baker Electronix first and confirm you're ordering the correct one
komodo (1:23:18 AM): and double check that it's compatible with your car
lecchilo (1:23:20 AM): yea true
komodo (1:23:24 AM): wouldn't hurt anything
lecchilo (1:23:25 AM): i will do that before i order
lecchilo (1:23:41 AM): i just wanted to ask a quick question about that diagram you had on the forums
komodo (1:23:52 AM): yep>
komodo (1:23:53 AM): yep?
komodo (1:24:00 AM): sorry, i can't type tonight, heh
lecchilo (1:24:03 AM): haha np man
lecchilo (1:24:07 AM): well what i wanted to ask
lecchilo (1:24:46 AM): where did you put your sim, under the car or under the hood... in other words... did you wire the sim to the ECU down under by the harness or did you follow the actual harness wires to under the hood and splice into them there ??
komodo (1:25:31 AM): nah, i first looked around the ecu near the hood, but the way the wires were run, it wouldn't go there easily
komodo (1:25:50 AM): so i actually mounted it under the car, ziptied to the brake fluid lines
komodo (1:26:10 AM): tucked up under, wrapped in protective tape
lecchilo (1:26:21 AM): oh ok
komodo (1:26:33 AM): of course all wires were very well wrapped and such, completely water proof
lecchilo (1:27:36 AM): so the 4 wires coming out of the sim... it's 2 signal wires, power and ground correct ?
lecchilo (1:28:23 AM): so 1 signal wire would go to 1 harness, 1 to the other, ground would have to be "made" into two wires and 1 go to 1 harness, the other to the 2nd harness, and same for the power wires, is this correct or am i way off ??
komodo (1:28:23 AM): yep, the single sim box outputs the signal returns for both sensors
komodo (1:28:51 AM): you got the signal part, but no need for so many splices on the power and ground
komodo (1:29:13 AM): just double tap one of the o2 sensors power lines (going to the sensor for the heater). it doesn't matter which one, power is power.
komodo (1:29:30 AM): for the ground, just choose one harness and ground there, then wrap up and seal off the other
komodo (1:29:39 AM): if the sim is grounded somewhere, it doesn't matter which harness
komodo (1:30:01 AM): no need to ground the sim to both harnesses, you know?
lecchilo (1:30:07 AM): ok
komodo (1:30:26 AM): and power, only tap into one power wire to one o2 sensor... if you connect all three wires together, it might short something
lecchilo (1:30:41 AM): ohhhhh... i'm dumb, you're basically providing power and ground for the sim right, it doesn't need both harnesses correct ??
komodo (1:30:44 AM): exactly.
komodo (1:30:46 AM):
lecchilo (1:30:48 AM): haha sorry
lecchilo (1:30:49 AM): it's late
komodo (1:30:53 AM): haha, it's fine
lecchilo (1:31:00 AM): ok and then what did you do with the o2 sensors..
komodo (1:31:07 AM): that's why UB is there after all. sharing knowledge and helping each other out
lecchilo (1:31:08 AM): i mean do they need to be good sensors or can they be old ones ?
komodo (1:31:23 AM): i believe old ones should work fine, as long as the heater isn't bad
komodo (1:31:38 AM): usually when an o2 sensor goes, it just doesn't return the correct signal, which wouldn't matter in this situation
komodo (1:31:58 AM): it'd probably just be trial and error for that. i personally used my two good o2 sensors
lecchilo (1:32:05 AM): oh ok
lecchilo (1:32:10 AM): i have like 6 old ones laying around haha
komodo (1:32:18 AM): haha, try them :0
lecchilo (1:32:19 AM): hopefully 2 will work out as i'm selling the 2 good ones
komodo (1:32:19 AM):
lecchilo (1:32:32 AM): and you just taped/zip tied the o2 sensors to the whole bundle ?
komodo (1:33:00 AM): yep, ziptied and tucked it up under. it wasn't going anywhere
komodo (1:33:11 AM): just make sure you seal all the wires very well, waterproofing any connections
komodo (1:33:25 AM): if you drive through the rain.. it could be bad unless done correctly
lecchilo (1:34:59 AM): yea
lecchilo (1:35:02 AM): i'll do that
lecchilo (1:35:10 AM): ok last question i promise
lecchilo (1:35:14 AM): the o2 sensors...
komodo (1:35:21 AM): no problem, ask all you want
lecchilo (1:35:38 AM): each of them goes to the different harness, and only 2 wires from each are used, power and ground aren't used??
komodo (1:36:39 AM): well, power is for the heater, so power is going to be used. signal and ground aren't
komodo (1:36:53 AM): the 4 wires from an o2 sensor are heater power, heater signal, o2 signal, and ground
komodo (1:37:04 AM): both heater wires are staying attached normally
komodo (1:37:19 AM): except for one power and one ground being tapped into (but not cut)
komodo (1:37:35 AM): (the ground on the harness side)
lecchilo (1:37:43 AM): sorry that's what i meant, signal isn't being used
komodo (1:37:48 AM): yep, you got it
lecchilo (1:37:55 AM): i didn't get the last part though... what do you mean except for one power and one ground being tapped into ?
komodo (1:39:18 AM): let me rephrase that. the ground isn't being tapped into, but rather redirected to the sim from the harness (to ground the sim to the car). take one of the heater power wires running from the harness to the o2 sensor, shave off a bit of the rubber, and tap into it with another wire, running that wire to the sim... thus giving the sim a constant 12v of power
komodo (1:40:03 AM): so the 4 wires coming out of the sim go to 1) a ground on the harness 2) a double-tap on one of the heater power wires, and 3+4) the two signal return wires to the harnesses
lecchilo (1:41:11 AM): haha man i'm sorry i'm so dumb
lecchilo (1:41:16 AM): what does double-tap mean ?
komodo (1:41:17 AM): actually, thinking back, i'm not positive on one thing. you MAY need to keep the ground going to the o2 sensor also
lecchilo (1:41:26 AM): ok ok
komodo (1:41:30 AM): so the only wire being cut from the sim would be the signal
lecchilo (1:41:35 AM): let's do it this way so we don't have to do it too long
komodo (1:41:40 AM): because now that i think about it, the heater circuit would need to be cut also
lecchilo (1:41:41 AM): ok
komodo (1:41:46 AM): erm
komodo (1:41:53 AM): the heater circuit would need to be grounded also*
komodo (1:41:53 AM): sorry
lecchilo (1:42:01 AM): ok ok
komodo (1:42:10 AM): haha, i didn't confuse you did i?
komodo (1:42:11 AM):
lecchilo (1:42:17 AM): completely
lecchilo (1:42:21 AM): but here
komodo (1:42:21 AM): haha
komodo (1:42:24 AM): okay...
lecchilo (1:42:29 AM): i'll get it now just bare with me for 2 more mins
lecchilo (1:42:30 AM): ...
lecchilo (1:43:00 AM): we have 4 wires coming out of each of the 5 things... simulator, 1 harness, 2nd harness, 1 o2 sensor, 2nd o2 sensor
lecchilo (1:43:01 AM): right?
komodo (1:43:22 AM): yes, but more than 4 wires... lol
lecchilo (1:43:26 AM): how so ?
komodo (1:43:28 AM): first of all, doubletap
lecchilo (1:43:32 AM): no no
lecchilo (1:43:35 AM): i mean separately
komodo (1:43:40 AM): ?
lecchilo (1:43:41 AM): everything has 4 wires
komodo (1:43:45 AM): ah, yes.
lecchilo (1:43:47 AM): ok
lecchilo (1:43:50 AM): haha i know i know
lecchilo (1:43:51 AM): you hate me
komodo (1:43:52 AM): sorry, i misunderstood you
komodo (1:43:52 AM): lol
lecchilo (1:43:54 AM): i'm dumb
komodo (1:43:55 AM): nah, it's fine
lecchilo (1:44:00 AM): ok then
komodo (1:44:01 AM): first of all, a doubletap
lecchilo (1:44:13 AM): ...
komodo (1:44:34 AM): that's when you take an existing wire, and without cutting it, you shave off a bit of the insulation and wrap a new wire around it, then tape it off (thus having a 3 way intersection of wires)
komodo (1:44:49 AM): this way if you have a power wire, you can tap into it like that and pull power to another circuit
lecchilo (1:44:56 AM): gotcha
komodo (1:45:00 AM): so the power coming from the car now goes two places
komodo (1:45:01 AM): cool
komodo (1:45:09 AM): now our setup...
lecchilo (1:45:11 AM): why is it called double tap, i thought of it as just tapping into a wire..?
komodo (1:46:01 AM): same thing. double for two circuits, but it's the same thing as tapping into a wire, just the verbage
komodo (1:46:08 AM): sorry
lecchilo (1:46:23 AM): ok ok
lecchilo (1:46:28 AM): ok now back to my noob setup...
lecchilo (1:46:31 AM): of all those wires
lecchilo (1:46:42 AM): which wire(s) will not be used whatsoever ??
komodo (1:48:39 AM): imagine the two o2 sensors plugged in normally. now cut both signal wires. leave the ground, and both heater wires connected normally.
the sim has 4 wires coming out of it.
wire 1: tap into on one of the heater power wires going (uncut) from the harness to one of the o2 sensors. this wire powers the sim with a constant 12 volts.
wire 2: tap into the ground wire (uncut) running from the harness to one of the o2 sensors. this grounds the sim.
wire 3 and 4: where you cut the signal wire on the two sensors, tape off the end on the sensor side, and connect wire 3 and 4 from the sim to the other sides, so the sim sends the signal output to the two harness signal wires, and thus tells the ecu everything's great.
lecchilo (1:49:33 AM): you're the best man
komodo (1:49:37 AM): got it?
lecchilo (1:50:04 AM): it doesn't matter where i tap into the heater wires and ground as in before or after the harness/sensor connection ??
komodo (1:50:16 AM): doesn't matter... it's the same wire
lecchilo (1:50:31 AM): that's what i thought
lecchilo (1:50:37 AM): yea i think i finally got it
lecchilo (1:50:38 AM): haha
komodo (1:50:48 AM): i'd recommend past the connector, on the sensor side. that way if you ever go back to o2 sensors, your harness (expensive to replace), isn't all cut up
komodo (1:50:49 AM):
lecchilo (1:50:58 AM): yea
komodo (1:51:25 AM): all right, awesome. mind if post this aim convo in that thread, so if anyone later on has any problems, they can read over this and hopefully understand it, and solve their problem?
lecchilo (1:51:30 AM): do you recommend doing it like that... plugging in the o2 sensors and cutting their wires, then tapping into their wires with the sim wires...
lecchilo (1:51:36 AM): n/m haha
lecchilo (1:51:39 AM): YES
komodo (1:51:51 AM): yes you mind, or yes i can? lol
lecchilo (1:52:19 AM): no no that was i dumb question
lecchilo (1:52:23 AM): so i'm asnwering it myself
lecchilo (1:52:52 AM): i mean all the wiring would basically go on on the wires betweent he o2 sensor and the harness right?
komodo (1:53:09 AM): pretty much. if possible, leave your actual harness untouched
komodo (1:53:21 AM): because that goes deep into the car, and to replace it costs a lot
komodo (1:53:31 AM): but the sensor wire is cheap'ish
lecchilo (1:53:47 AM): yea
lecchilo (1:53:51 AM): especially since i have 6
komodo (1:53:58 AM): there you go, lo
komodo (1:53:59 AM): lol
lecchilo (1:54:02 AM): thanks again man, i'm going to order this tomorrow
komodo (1:54:12 AM): cool, i'm gonna post this up for others
lecchilo (1:54:14 AM): i emailed them tonight asking what i need to order
komodo (1:54:18 AM): good luck, and let us know how it goes