6G Celicas Forums

Nice. So the starter was being powered directly out of the ignition switch. It's a wonder the ignition switch didn't go bad. Actually, it's a wonder that it didn't blow that fuse on that circuit....

-Doc

acutally, it did,...apparently RJB stuck a 10amp fuse in there.
im surprized that held.

But what about those two wires from the efi relay I posted about? Are they soldered into a Y or is just one of them connected? I'm dying to find out how yours was done, and its too cold out to go unwrap mine and check.

Luckily I decided against extending my harness, so all the factory shielding is still there.

Doing this harness from scratch made me really understand how some of these harnesses were hacked up. Not exactly that anything was done wrong or whatever, but that things could have been done differently. For example, in my harness I still have the male and female IG1 and IG2 plugs connected together and then the wiring to the 3rd ecu plug and interior plugs was ran from there. Why? Its WAY cleaner to just cut those plugs off and wire the interior and ecu plugs directly! Arrrg...

It really makes me want to pull out my own harness and clean it up.
I'll be adding a dedicated wire from the battery to the fuel pump soon. Looking at the supra wiring diagrams, that pump is on its own efi relay with a 30amp fuse, while ours shares its power from everything efi related, through a 15amp fuse and really thin wiring.

yea the wires go together

I did a quick voltage drop test between the battery and the fp pin in the diagnostic box. I got 1.6v drop! And thats just at idle! To say that our upgraded fuel pumps shouldn't be hooked up to the factory harness is the understatement of the year!

This post has been edited by lagos: Jan 5, 2009 - 4:31 PM

I need some help figuring this out...

So, the way the whole starting system works on the Alltrac is very different from the way it works on a 6th gen car.
On the Alltrac the clutch start switch acts only as a switched GROUND for the starter relay coil.
On the 6th gen, the clutch start switch acts as a switched 12v line for the starter relay coil.
So since we are dealing with the same car, and the same fuse box, you can simply run a wire directly from the clutch start switch to the relay using IJ1 pin 17.
Simple enough, right?

Here is where it gets tricky.
On the 6th gen the "switch" part of the rely sends power through the fuse box, and directly into a single wire that goes to the starter.
The alltrac on the other hand sends that same wire not only to the starter, but also to the cold start injector, time switch circuit opening rely, and Ecu STA signal, and that wire is actually part of the main harness and does not go directly from the fuse box like it does on the 6th gen.

The 6th gen however uses the actual clutch switch, that then goes to the starter relay's coil, to send power to the COR and STA Ecu pin, and there does not seem to be a cold start injector (excuse my noobness).

So how would you go about wiring this up then. Would you take the starter wire thats part of the 3sgte harness (same wire that goes to eb1 pin 2) and Tee it off to the single wire that just goes to the starters switch, and then run a brand new wire from the clutch start sw IJ1 pin 17 directly to the starter relays coil and to the ecu STA pin ?

This would be the "alltrac way" of doing it, instead of having the coil part of the relay send voltage to the cold start injector, cor,etc...

This post has been edited by lagos: Jan 9, 2009 - 3:50 AM

in my harness we set it up to go from IJ1 pin 17 and taps into the pin 3 (solid black) from the COR.
and yes, we have no cold start injector. the ECU has cold start trims that adds the extra fuel.

right, but if you do that, you are powering the cor, the cold start injector, etc.. from the clutch start sw wire that powers the magnetic coil inside the relay, when in the alltrac its powered from the the "switched" wire that only goes to the starter. If look at the wiring diagrams for both cars, you'll see what I mean. Both of them are wired totally different.

This is also why your starter relay was wired wrong, because on the 6gc the thinner coil wire actually does power the cor and other stuff in the car.

yup. thats how dave wired it up.
we just added in the clutch start switch (dave had it set up to start all the time, didnt have the clutch start switch at all.)

So are you saying you ran a brand new wire from pin 17 clutch start sw, directly to the starter relay and nothing else?
If you do that, then you also would have to take the 3sgte starter sw wire and the 6th gen starter sw wire and join them together. Then wire the cor pin 3 to IG2 pin 20, and the ST ecu pin.

That way when the starter cranks, it will send power through the starter sw wire to the cor, cold start injector, cold start sw, and ecu. That would probably be the proper way of doing this.

This post has been edited by lagos: Jan 9, 2009 - 7:00 PM

Art, was the car that your doing this harness for origianlly an auto or a manual ? (the car it's going into)

This post has been edited by Batman722: Jan 10, 2009 - 12:06 AM

Always a manual. Its just a difference in how the 6th gen powers the starter relay, cor and ecu, vs how the alltrac does it.
On the stock 6th gen, both of those relays and ecu signal are just triggered/powered by the clutch start switch, because they are relatively low powered circuits.
However on the alltrac, you also have the the cold start injector, and time switch on that same starter circuit. So instead of using the clutch switch, the alltrac uses the same wire that goes to the the starter switch.

So what I think I need to do is wire it up so that i run brand new wire from the clutch start sw to trigger the starter relay, and send a starting signal to the ecu. This way the clutch switch is only triggering one relay and sending starting signal to the ecu. Then once the starter relay clicks, I need to Tee off a wire from the 6th gens starter switch wire, to send power back through the harness to the COR, Cold Start Injector, and Time switch. This would be kind of a hybrid way of how the alltrac and 6th gen cars deal with that circuit.

It seems like this would be a very simple thing to wire up, but if you really take a close look at both diagrams and see how the power runs through the harness, you'll see what I mean. I'm willing to bet that a lot of people just power the all of those things though the clutch switch 12v, and thats why a lot of swaps need some extra cranking to get started in the winter.

This post has been edited by lagos: Jan 10, 2009 - 3:08 AM

we added a wire at pin 17, and tapped that into the black COR wire.
dave just had a jumper soldered in.
if i have my way, i wont be using the CSI anyway.

I assume this is what you PMd me about... and yes, that's exactly how we do it also, it seems like it's the safest and most "factory" way to go about it. It also allows for the least number of connections. Well done.

-Doc

This post has been edited by Dr_Tweak: Jan 10, 2009 - 11:32 PM

I was really wondering how you handled that circuit since there are a bunch of different ways someone could wire it up and still make it "work".
All of this really makes me want to tear out my own harness and go over everything, but since the car is my daily, I cant afford the down time.

This post has been edited by lagos: Jan 11, 2009 - 1:49 AM