eallanboggs

iTrader: (1)

I don't have the schematic in front of me so I'm just going by what most computer controlled circuits do these days. A relay has two circuits in it. One is the control side(coil) and the other is the LOAD side(High Currrent side which does the actual work). The coil needs 12Vdc and ground to make the connection on the LOAD side for the device(Starter) to work. When you turn the key switch 12Vdc is put on one side of the coil. If all the conditions the ECM says need to be met for the starter motor to work are met you will have ground on the other side of the coil. As I mentioned this might require the transmission to be in Park or Neutral or in the case of a manual the clutch may have to be depressed. There may be other conditions that have to be met as well. You need a schematic to be sure. Are you trying to do this blind? If so, good luck cause you'll need it. Better to play the Powerball instead Once all the ECM conditions are met you should have continuity between the chassis and one side of the relay coil circuit. You'll need a schematic to find out which side of the coil is HOT and which is ground. You do know what a continuity test is, right? You can also make the starter motor crank by putting a jumper wire between pins 30 and 87 with the key in the S position assuming the starter motor is good.

SuperC1

iTrader: (4)

I have the schematics and everything looks good, pin 30 is hot at all times, I'm sure the relay is working cause i can hear it click when the key is turned. I starting to beleive that the pcm ground is not there, because all the hot + connections are fine.

eallanboggs

iTrader: (1)

Ok, next step is jump 30 to 87. Does it crank? Yes:Look for 12Vdc and ground on the relay coil pins 85 and 86 when key is in S position and all ECM conditions for starting are met. No:Test starter motor and associated wiring. I don't want to get you into trouble, but you can confirm your suspicion about the ECM not supplying ground. You have to be able to back probe the ground wire going to the relay coil. You'll have to lift the fuse panel from its' base to backprobe the wire. Put a "T" pin in the wire and take an aligator jumper from the "T" pin to chassis ground. If the ECM is failing to supply ground when asked to the puts the ground on the starter relay coil. If everything else is good the engine should crank when you substitute the ECM ground. If this jumper trick works you'll have to probe ALL the inputs to the ECM for the ground starter circuit. If they're all good the ECM is faulty. If not troubleshoot the missing input. There isn't much else left to check. This isn't a complex circuit by any means.

eallanboggs

iTrader: (1)

I just thought of something after rereading your last post. If you "hear" or "feel" the relay pick that doesn't mean the LOAD side of the relay is good, but the coil circuit(control side) is GOOD. That means the ECM is supplying ground when asked to and the key switch is supplying 12Vdc so don't waste your time troubleshooting the ECM ground feed because it is good. You problem is on the LOAD circuit which is even easier to fix.

SuperC1

iTrader: (4)

Jumped the relay under the hood, car cranks , but still no crank from the driver seat . Tried to ground the relay from the chassis but still no start, running out of ideas.

eallanboggs

iTrader: (1)

You jumped 30 to 87 and it cranks. That eliminates the LOAD side. You can hear the relay energize when you turn the key so that eliminates the coil side. What's left? That's easy. You should have tried that solution first. I always do.

SuperC1

iTrader: (4)

What's that? I'm going to go back and check the ignition switch again tommorrow, but other than that there isn't much left. Battery is good, starter is new, ignition switch has been replaced, can't throw much more money at it. I'm still suspecting vats. I have it tuned out in the pcm but I'm wondering about the key now.I tried grounding the relay, but I'm not sure I was doing it correctly, I'm hesitant when it comes to cutting wires, usually thats a last resort.

eallanboggs

iTrader: (1)

You don't troubleshoot with any consistency. Why go back over things you've already checked? The starter cranks when you jump 30 to87. What does that tell you? You said the relay energized when you turn the key. What does that tell you? Don't retrace those steps if you have PROVED those circuits are NOT the problem. What's left? The relay! Or you're not reporting your results correctly. Don't cut wires. I suggested using a "T" pin for backprobing. They are minimally invasive and you can repair the tiny hole they make with liquid tape or finger nail polish.

SuperC1

iTrader: (4)

Ok, I went back over everything again and this time I found my problem, it was the ignition switch, and actually not the old one but the new one. When I replaced the old one I didnt have the new one lined up just right and I wasnt getting 12v when I turned the key, so I went back and dropped the steering column again and made some minor adjustments and vroom, she came to life. Thanks boggs for all your help, man this was discouraging, I appreciate the patience. For anyone else who runs into this problem all I can say check over everything, and when you think you've checked it all, go back and check again, I garuantee you've looked over something. Thanks again everyone for your input.