ScottURnot

iTrader: (33)

Hey guys, I have a problem I was hoping to get some input on. My car has been running great until this morning, I shut it off and went to start it and nothing.

Here is what I know its not.

The battery is good!-I have checked it
The starter is good!-I can jumper the starter poles at the starter relay and start it.
The starter relay is good-I checked it out.
It is not the neutral/park saftey switch- I allready bypassed it.

It is not getting power too the starter relay trigger coil, it just does nothing. everything else acts normal. It acts just like a clutch/park/netral safty switch but I checked. What else could it be? If anyone has a electrical diagram of a 97 sc400 they could send me to help that would be great! Anyone ever had this?

SATXSC400

^ did you measure the voltage at the starter. Sometimes with a worn out/bad contact iginition switch voltage drops by time it reaches the starter. Also make sure your grounds are all good.

LexusFTW

iTrader: (7)

Does the starter solenoid click or make any kind of sound? Did you check the voltage at the starter relay in the fuse box?

RedPhoenix

iTrader: (10)

I just had this problem. When in the ON position does the CEL on the dashboard show up? Mine did not, faulty computer.

Worth a look.

ScottURnot

iTrader: (33)

The starter works perfect if I jumper the pins at the relay. Power from the switch does not go to the starter, it just triggers a relay pulse coil thus tripping a larger power source.

Yes, I am getting no power to the trigger pulse coil side of the relay. Good power on the relay power supply. It just has to be somthing from the switch to the relay.

All dash lights work, I jumpered the start relay poles and started the car and drove it home. The funny thing is the cars dash seemed like it never knew the car started. All the lights stayed on on the cluster like it does when you turn it on before it starts. Probally because I didnt actually start it with the key.

I am starting to wonder about the Anti-Deterrent ECU:anyone know how it functions?

LexusFTW

iTrader: (7)

Scott, that side of the relay is powered by the neutral safety switch when the ignition switch is engaged. Have you double checked your connection you made for the NSS?

Im doubtful that its the theft deterrent ECU. Do your locks work (lock/unlock)?

ScottURnot

iTrader: (33)

Well, That was my first thought. I checked it and even put a jumper right down on on the transmission plug, still nothing, is there another place closer to the fuse block I could jump it?

LexusFTW

iTrader: (7)

Since you're still running the SC400 auto harness, the end of the connector is probably your best bet. Did you double check to make sure all your body plugs are securely fastened?

ScottURnot

iTrader: (33)

Which body plugs? No luck finding anything tonight.

c0wboy

In electronics, where the electricity stops that's where your problems begin. On the Supra, the ground from the start relay is supplied by the theft deterent ecu. One thing goes wrong and the car won't start. Here's what I did to bypass:

Assuming you've checked all fuses,

First, give the start relay a dedicted ground to bypass the theft ecu. Turn the key and see if the car starts.

If not, locate the ign wire and tap into it. Run that hot line to the 12V trigger on the relay. Turn the key again.

If nothing, run the 12V trigger to battery + and TAP on the positive lead. The starter should fire.

If not, run a larger thick line from the relay starter power to the starter itself and again TAP on the battery lead. The starter should fire.

Thanks Scott, let me kow if it works.

Eric

kyoso23

Double check your grounds man.

ihiryu

iTrader: (7)

....what about the ignition switch? I had to rewire mine to a button for temp. purposes until I got one from my toyota dealership.

ScottURnot

iTrader: (33)

I wonder how I could test for that?

ihiryu

iTrader: (7)

on my car it, the wire that starts the car is a white/black wire IIRC. And just bypass it, you are intercepting the ignition switch with another switch

kyoso23

Time for a pushbutton start maybe?