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Discussion Starter #1
Intro: What's up guys! I'm doing a full Supra USDM GTE 6 speed SC300 swap for my buddy. Everything is already installed! Wiring already done via $200 manual from the dood from Hawaii.

Problem: Starter will NOT crank over!!!

Note:
-The starter is properly installed, ground and power properly hooked up and getting voltage.
-EFI fuse and coilpacks pulled for first time start up.
-Ground connected via block/chassis just like stock.
Turn key, nothing!

Troubleshooting:
-Battery is fully charged and can deliver proper amount of power.
-We tried different positive/negative lines to starter. No damage lines.
-All fuses fine.
-Starter is working perfectly. We even brought them both to AutoZone/Kragen's.
-Bypassed the EB-connectors right behind the battery and tried getting the starter to spin on the floor. Wired the starter straight to the battery on the floor, still won't spin.

Note:
-This all is being done with the ECU disconnected and 1 or 2 sensors of the chassis harness unclipped/unconnected in the ECU location. Reason being: I still want to double check the thousands of wires I soldered.

-We finally got the starter to spin on the floor by: grounding the starter's actually housing and not the ground location, power connected to the opposite end of the starter, NOT where the stock spade would normally connect to.

My question is:
1. WTF am I missing here? The ECU doesn't need to be connected for it to at least crank over correct? Hell, I disconnected my alternator/ECU on my own Supra to just make sure. Only thing is, when we ran into this problem, his ECU was connected except for 2 sensors near the ECU area which were probably stuck half way down the firewall when we were feeding the loom. If that matters at all, I'm going to most likely finish double checking the wires and connect everything else in the passenger leg area since that was the only thing, touched inside the car itself.

Any ideas?

-Vince
 

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Swing on deezz!!!
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Hey Vince...if you're hooking a ground wire directly to the starter that's the issue. The starter grounds through it's casing to the engine block and bellhousing. If you didn't put all the little ground straps back on the engine, that's why it won't turn over. There is no ground terminal on a Toyota starter. The ground cables go from the battery to the engine block(or mount) to the body. There are multiple ground straps from the engine to the body so that the various engine managment systems and starter will work properly. Proper grounding also prohibits the onset of electrolysis in the cylinder head. You should only have two wires to the starter.. key on 12V power at the soliniod terminal to activate the bendix, and the heavy gauge load wire directly from the battery to the large copper terminal post on the starter. Hope that helps you out. Most commonly ditched ground strap is the one at the transmission...and I've had no start conditions from it being absent in the past.

Mark
 

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Discussion Starter #4
Ok I found the problem. In regards to the GTE/SC300 swap, there will most definitely be 2 or 3 harness clips left over in the ECU area along with 1 unused female clip for the chassis harness. I haven't checked out the schematics for the Supra yet to compare with the SC300's starter wiring to see if they are identical in terms of location because nearly 95% of the engine harness needs to be cut. The problem was the Starter wire to the chassis harness, directly in the ECU area was disconnected. I assume it runs to the fuse box and relay that triggers the switch when the key is turned. Sighs, I knew it was right under my nose.

SJ - Thanks for the link bud! If it's not posted as a sticky, it should be!

ra24man - Many thanks! Even though I already fixed the problem, I still read every word. Very informative for future references also. Btw, absolutely all ground were connected, checked, double checked, triple checked. :)

-Vince
 
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