Remote Start wiring help

[5uprahboy]

Hey guys,
My car’s not going so I cant do much in the way of testing, or finding out for myself, and spinning the alternator by hand, doesn’t seen to have the desired effect :icon_razz
I’ve search the forums and only found people talking about their alarms and how they were installed for them, however I like to do everything myself, so I know what everything is doing, and why.
I have a remote start alarm that requires a 12v feed when its remote starting to tell the alarm that the engine is running and to stop cranking (the alarm will try up to 6 times otherwise).
I was thinking of running off the oil pressure circuit, but as it turns out, not enough oil pressure is gained while cranking for me to use this, so I’ve decided to use the charge circuit.
Because I require +12v (which is the opposite to the little battery light on the dash as it has +12v when the car isn’t started, but nothing when it is) I was thinking of using a relay to reverse the situation. I realise now though, that this is not really a good way do to this as the charge light circuit is a “light-weight” one.

On the back of the alternator, other than the main charge cable, is a plug with 3 wires going into it. Which one of these is the one I should be “tapping” off?

Attached is a picture of the plug in question.

Thanks

Hunt

 

[kuongie]

hey man if you could specify exactly which wire your trying to hook up from the alarm i could probably help you out a lot more, or anybody else for that matter. i install alarms and anything mobile electronic for a living, if your trying to find out which wire off that plug is a constant 12 try using a multimeter, scratch some paint back behind your driver kick and probe that for ground and probe the wire your trying to find and your multimeter should tell you 12v or 0.

 

[5uprahboy]

hey man if you could specify exactly which wire your trying to hook up from the alarm i could probably help you out a lot more, or anybody else for that matter. i install alarms and anything mobile electronic for a living, if your trying to find out which wire off that plug is a constant 12 try using a multimeter, scratch some paint back behind your driver kick and probe that for ground and probe the wire your trying to find and your multimeter should tell you 12v or 0.

Hey,
I need a feed that has 0v when car is off or when cranking, but this changes to +12v when the car is running.
The alarm uses this +12v so it knows that the engine is started and to not keep cranking.

 

[kuongie]

what kind of alarm are you using?? i shouldve asked you that first sorry

 

[5uprahboy]

I cant remember the name. Its not a known one at all. I dont even think it has a name. There are no wiring diagrams for it online - just a very basic one that came with it. But that's irrelivant anyway as I know how to wire it up, I just don't know what wire in the supra I should use.

 

[kuongie]

I cant remember the name. Its not a known one at all. I dont even think it has a name. There are no wiring diagrams for it online - just a very basic one that came with it. But that's irrelivant anyway as I know how to wire it up, I just don't know what wire in the supra I should use.

Try the tach wire, its in the plug under your hood that has diagnostic on the lid. Its the black wire off that plug. The only reason I asked what model it was is so I could specify my answer and be certain which wire you are trying to tap. Normally on lets say a Viper or Ungo, the brain would reference the learned tach signal and disengage the starter. But the thing is, the tach has only between 1v to 6v and is ac current. Its a shot but I dont want you to fry something unless im absolutley sure it works...:dunno:

 

[Evilempire1.3JZ-GTE]

You should not use your tach it is - pulses or small 5vdc pulses or what ever it shoots them out when #1 fires to the tach

i think you were on the right track use the battery check wire it is yellow green or something it goes to the gauge cluster it will turn off when the runs,
or rune a timer circuit so after roughly the mount of time it takes to start the car once it cranks it stops so if on avg it takes 3.5 seconds to start car from inital cranking just have it hooked to a timer circuit so it cranks for 3.5 seconds the stops.

 

[5uprahboy]

I cant use a timer circuit as the remote start will try for a 2-3 second burst then stop for 2-3 seconds, if it doesnt get signal that the car has started then it will go again. I will just use the charge light with a normally closed relay. Thanks for your help everyone! I'll post up my results once the car is going

 

[5uprahboy]

Hey guys,
Well I have a question.
I tried to use the charge light circuit from the dash board, but, when using remote start, the dash light, or ACC isn't powered up (much like a properly wired in turbo timer does), and as such I cant use the charge light.

So my question is this:
Which one of the wires coming out of the back of the alternator, is +12v when the alternator is running?

Cheers

Hunt

 

[Evilempire1.3JZ-GTE]

time to get a meter there is only 3 4 wires there

 

[5uprahboy]

I don't have a running supra to put the meter on sorry.

 

[5uprahboy]

Found which one to use. Yellow wire in drivers side kick panel. Comes straight from the alternator, along top radiator support, through inner guard and into drivers kick panel.
Sits in a faily large plug but only 3-4 wires are occupied.
It's a pretty chunky wire as well.

 

[Evilempire1.3JZ-GTE]

yes that wire also goes into your charge light behind the gauge cluster and on pre 89 it is yellow/green at the dash

 

[5uprahboy]

Yes but when it's at the charge light, its got power when the car isn't running, and none when it is (hence the light going out when the car's going). However, down at the kick panel, it has power only when the car is running.