Printer Friendly Forum Posts - 07 rx350 is there a tach wire in cabin?

Hi guys,

I started R/S install on my 2007 RX350 today, everything is going good except the tach wire which needs to go to an injector under the hood. Running wires through the firewall has proven to be a total pain in the butt. There's no access at all from under the hood and very poor access from within the cabin. I've spent about two hours trying to do it but have failed so far. The two times I managed to run a cloths hanger through, the pulling back of a taped wire failed. Might try soldering the wire to the hood hanger tomorrow.

Is there a tach wire somewhere in the cabin that I can tap? It seems Highlanders have a ODB2 one on pin 9 but my RX does not have that pin connected.

Thanks :)

Alternative might be instrument panel or engine management, you'd need to either test every wire or obtain circuit diagram/pin outs.
PS wrap the wire round the coat hanger then spray WD 40, that's an alternative.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

3 places for tach wire:

WHITE (AC) behind gauge cluster
WHITE (AC) ECM behind glovebox Second connector pin 1.
WHITE (AC) Steering column Junction Connector towards bottom pin 2 of 12pin plug

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Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert

Thanks

How would you test AC write?

Sorry, meant how would you test a AC wire when all constants are DC.

DMM, set to 20VAC, black probe to ground, red to suspect wire 1.5 -5 VAC on engine run only.
Technically it isn't AC it's a DC pulse but it tests on a meter as AC.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I agree with Howie, and also as a general rule, an installer (especially a novice) should NEVER connect to wires in the car without testing them first.

On the other hand, the tachometer wire on the remote starter is only an input, not an output. So, I think if all else fails, it's OK to connect the tachometer wire to the suspected wire in the car, and try to program tach to the remote starter. If it programs, try the remote starter and make sure it works. If it doesn't program, it's the wrong wire.

X 2 with Chris and sometimes I attach without soldering, the tach wire to suspect wire then program tach. In theory at least on older Cliffords there was a megohm resistance so you are unlikely to do any damage.
But then it's moot, test the wire(s) Ted gave you.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

In case you have an auto ranging meter, don't use the auto feature, set it to manual. Like Howie mentioned, it should range between 1.5-5V (should fluctuate if you rev the engine a little).

To be honest, i don't ever recall testing for tach. I would simply hook up to "tach" wire and try to program the unit. It it doesn't then i start wire hunting.

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Ted
2nd Year Tier 1 Medical School
Still installing as a hobby...pays for groceries
Compustar Expert

That's exactly what I was saying Ted, except you explained it better.
Big secrets.
a) Know where to look, coils (once upon a time) injectors even Camshaft position sensor. Rear of instrument panel on some cars, note 3 wire connections to tach gauge, 12V+ign, ground and tach. Most Toyotas and BMW, pin 9 on OBD ll socket.
b)Rarely use a meter, I use a Mac 120 RED / green LED tester much quicker than using a meter.

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

Thanks guys, I actually managed to run wires through the firewall by soldering them to the clothes hanger and hooked it up to a injector.

I have the remote start part working, car starts just fine.

howie I saw your post regarding RX350 two step door unlock but I'm not quite sure about it. I'm running wires to the driver door switch, I can get them to lock and unlock but the 2-step unlock is a hit and miss. Sometimes it will work and other times it wont, it seems this APS997E doesn't like quick button presses or something.

Any suggestions?

Thanks

Could you remind me? Link etc?

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Amateurs assume, don't test and have problems; pros test first. I am not a free install service.
Read the installation manual, do a search here or online for your vehicle wiring before posting.

I'm more familiar with the "C" line of Prestige and Pursuit starters, as the E series just came out. I've done quite a few of the entry level E stuff, but not yet an APS997E.

I have two suggestions for you, especially with Toyota/Lexus.

1: Go into programming, and change the door lock setting to....I think it's the last setting? The one that has 350ms unlock pulses. That should work better.

2: If that doesn't work, turn 2-step unlock on, and splice the RED / black second-unlock output onto the green first-unlock wire that you already have connected to the car.

howie ll wrote:

Could you remind me? Link etc?

#4 https://www.the12volt.com/installbay/forum_posts.asp?tid=117264

Chris so 500/350 option means 500 lock and 350 unlock?

posted_image

I did play with the 10th feature option for 2-step unlock, but that would simply unlock all doors when hooked up to the green door wire. There's no separate wire driver and passenger doors as far as I know.

Oops I meant grey not green in the driver door for unlock.

Chris ..just saw your post form 2003 (!) regarding RX300 auto headlight shutdown using driver door pin wire. Will try that on my 350, hopefully I can locate the proper wire.

For anyone that comes across this thread looking for RX350 auto headlight solution the driver door pin switch trick worked perfectly.

On my 2007 it's a thin gauge black wire located in driver kick panel at the very bottom. Did a direct connection to my R/S ground pulse after shut down and the lights timed out after 30 seconds just like they normally would have.

Good to know. Is there also an autolight wire from the headlight switch that can be interrupted?

I recall using a relay to interrupt the autolight wire on an IS300.

Most likely there's a wire but will require a relay. The door pin is way simpler and no relay, wire is easy to access and no hacking around.

I used to have an IS300 and had a shop install R/S on it. I guess they were lazy because the lights would not time out.

I'm down to mounting the modules/wire organization and putting the car back together. Was planning on hooking up rear defrost but no clue where the trigger wire for that is so that's it for now. This was an experience that's for sure :)