Engine not cranking!!! Replaced ign switch??
Engine not cranking!!! Replaced ign switch?? Alright, this started last Thursday night while I was getting ready for a track rental Friday. I went to start the car to back it outside to wash it, and all I got were some clicks under the hood. No big deal, the battery doesnt seem to be the greatest so I just threw the charger on slow charge and left it overnight. Next morning I go to start it to put it on the trailer, just clicks. I search on here for the better part of the day, and figure it must be the starter. Jumped a hot wire to the solenoid, and it fired right up. So, I went to the next step in my research: The ignition switch. Man what a pain in the *** that is. I have the new one on, everything hooked back up, and still get nothing but clicks. Now this car has been stripped out, and a lot of stuff removed. The small black plug in the switch only has 1 orange wire coming out of it, and the BCS has a plug that is not plugged in. Now the car was running perfectly when I parked it a week before I started having the issues. I'm close to just wiring up a relay and having a super cool push button ignition. I snapped some pics of the BCS, some random plugs close to it that arent plugged in, and the ignition switch. I've checked the fuses and relays, and all are ok. I'm stumped, and clueless as to what's going on with this thing. I hate dealing with **** like this.
Cliff notes: car wont crank, starts if solenoid is jumped, replaced ignition switch, still not crank, fuses/relays checked, pissed.
Cliff notes: car wont crank, starts if solenoid is jumped, replaced ignition switch, still not crank, fuses/relays checked, pissed.
Sounds like it's time to get out the multi-meter. Start at the ign switch and work your way forward. I don't think I've ever seen the starting diagram for an ls1. But I have had a harness apart and it's just a purple wire that goes to the starter. It should be the one that get's 12V from ign sw. The wires that go to the BCM are for vats and shouldn't have anything to do with the purple wire going to the starter.
Also make sure all the grounds are nice and tight. (3 behind drivers head, ground strap from engine to frame, battery (-) to engine and shock tower). Also if it's a vats problem I don't think it would cause it to not do anything. It usually lets the engine run for 2 sec or so and the BCM shuts off the PCM from sending power to injectors. So I still think this may be ign switch related or maybe bad connection at one of the terminals.
Also make sure all the grounds are nice and tight. (3 behind drivers head, ground strap from engine to frame, battery (-) to engine and shock tower). Also if it's a vats problem I don't think it would cause it to not do anything. It usually lets the engine run for 2 sec or so and the BCM shuts off the PCM from sending power to injectors. So I still think this may be ign switch related or maybe bad connection at one of the terminals.
I did put the voltmeter on the purple wire on the ignition switch and checked continuity with the one on the starter, no dice. Is is the same wire? They're both about the same size, but the color is a little off. The switch has slotted holes, could it be out of adjustment, and that's causing it not to start?
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Sounds like a classic bad battery. How old is yours? (BTW - Testing the voltage at the battery terminals won't tell you if its good or not but any local auto parts store can put it on their tester can confirm its cranking capacity.)
I'm not sure how old the battery is. I suspected a bad battery the first time it wouldnt crank, so I hooked a charger up to it and set it to "start". It still wouldnt crank. The battery does have enough *** to crank it when I put a hot wire to the solenoid on the starter. I've switched the fan relay with the ignition relay already, no dice. I guess it's getting a push button ignition. 
If the starter clicks, there is not enough voltage to turn the motor. You either have a bad Battery or Battery Cables. Since you said the Battery worked to jump the starter with another Hot Wire, my guess would be the cables.
The clicking seems to be coming from the relay area, not exactly sure where. I'm going to get somebody to turn the switch tonight to see if I can pinpoint the click. Thanks for all the suggestions guys, this thing is whoopin my ***.
Ok, so I went to town with the test light and muiltimeter. What I've found is that I'm not getting a ground, or switched 12v to the starter relay. It looks like the ground is controlled by the N safety switch, and the switched 12v comes from the BCM. Would one going bad affect the other? I find it hard to believe that they would both go bad at the same time.
Look at the diagram I posted above. Actually the BCM supplies the ground, and the dk grn wire is the 12v to activate the relay. So when you have the key in start position 12v should be on the dk green wire.
Dude, that wiring diagram saved my sanity! Something finally clicked in my brain, and I was able to trace the issue down to the BCM. It wasnt providing the ground to the relay. I rigged a ground wire to the relay, and viola! It started. Now my next issue: Should I just ground the relay and not worry about the BCM, or should I replace it. The cars wiring is stripped down to not much more than the essentials now, so I'm leaning towards grounding it. Is there a possibility of negative side affects from just bypassing the BCM?
