So over the last few weeks I've been butting heads with a rogue no crank issue. Picked up my brother's 04 4.2 Trailblazer, mother owned it before him and her man made sure it was serviced liberally and kept in great shape. In the 2.5 years my brother's had it I've hounded him about keeping it in good condition. Of course the 2nd day under my ownership I go to change the oil because ill assume he hasnt in 7-8000 miles. Get some fresh oil in her, go to start it up and..... Nothing? I'm certainly no mechanic, and absolutely worthless with electrical diagnosis, but I tend to enjoy learning by watching and listening to the people who know what to do. This time around however, I'm pretty gassed out. Hoping someone can point me in a good direction. That being said, here are the steps I've taken.
1. Oil change then no crank - gauges light up in ON position, radio, AC, etc. all functioning, as well as a brief series of electrical clicks -> turn key to crank and all dash cluster gauges and lights cut out -> key springs back to ON and gauges/lights reset with battery light remaining on.
2. Battery tested 12.5V w/ multimeter. Then tested at Orielly's, checks out good. Only 4 months old.
3. Replace ignition switch - no effect
4. Pulled starter out & bench test - OK
5. Put back in, no crank still. Full voltage from battery to starter // measure voltage to all fuses
6. Jumped starter from constant to trigger post. Starter clicks in but no spin (trying at ignition no click, same as before)
7. Ignition locks up can't get key to turn, attempt to break through cylinder with screwdriver end up drilling out and
replacing (possible damage to ignition harness?) *really wish I would have done a little more research before
committing to this...*
8. Replaced computer with ordered VIN flashed PCM.
9. Security relearn on new computer/ cylinder & keys
10. Starter now clicks with ignition crank! After many attempts (also a few starter jump attempts) of troubleshooting, starter no longer clicks from ignition....
11. Install new starter - still no crank no changes. Voltage at bottom wires in ignition harness, Red (constant) and with key on - White (transmission) and Orange? Not sure. Yellow wire gets voltage during ignition crank attempt.
12. Vehicle starts flawlessly via remote start with key in on position, wont start without key turned on, it tries three times with the same results as trying with key at ignition. Vehicle dies when brake is depressed (function of remote start system). Successful remote start brings following transmission codes - P0740, P0785, P1860
13. After watching MAY03LT's video I measured voltage at fuse 47 under rear seat fusebox while key is on - battery voltage at each side of fuse.
At this point I'm convinced it's the remote start, an ignition switch issue, or given the codes and the guidance in the video, a transmission solenoid.
Throughout the course of this headache I've swapped the new and old ignition switch 2-3 times trying different things. I lost track of the proper gear alignment from the switch to the ignition harness. Spent hours the other night trying different positions hoping to get a start. Mostly end up with key out and ignition positioned to off while accessories are still running. (Gauge illumination, battery light, stereo etc.)
Ended up calling the company that installed the aftermarket remote start years back, inquiring about how to take it out. The guy I spoke with assured me there's no security/alarm and no starter kill relay in this system, and that there should be no correlation... Though I wonder if the way they've wired it could be causing my issue now, mind you my mom had it installed 4 years back and it hasn't posed an issue in any of that time.
Finally last night as I spent a few more hours adjusting the positioning on the ignition switch I figured, "well I haven't jumped at the new starter yet". I've since saved and cleared the previous codes I got, so I figured I'd see if I get the same thing. Nope. Started right up (key in ON position) with no codes. Being as I wasn't as afraid of my transmission blowing this time I thought I'd try and take her for a ride. Drove around the neighborhood till operating temp, then took to the main roads and put a little strain on er. Nothing. No codes. Drove great. Yet still, no start.
Any idea's on what to pursue here? Appreciate anyone taking the time to give this a read/throw some guidance my way.
1. Oil change then no crank - gauges light up in ON position, radio, AC, etc. all functioning, as well as a brief series of electrical clicks -> turn key to crank and all dash cluster gauges and lights cut out -> key springs back to ON and gauges/lights reset with battery light remaining on.
2. Battery tested 12.5V w/ multimeter. Then tested at Orielly's, checks out good. Only 4 months old.
3. Replace ignition switch - no effect
4. Pulled starter out & bench test - OK
5. Put back in, no crank still. Full voltage from battery to starter // measure voltage to all fuses
6. Jumped starter from constant to trigger post. Starter clicks in but no spin (trying at ignition no click, same as before)
7. Ignition locks up can't get key to turn, attempt to break through cylinder with screwdriver end up drilling out and
replacing (possible damage to ignition harness?) *really wish I would have done a little more research before
committing to this...*
8. Replaced computer with ordered VIN flashed PCM.
9. Security relearn on new computer/ cylinder & keys
10. Starter now clicks with ignition crank! After many attempts (also a few starter jump attempts) of troubleshooting, starter no longer clicks from ignition....
11. Install new starter - still no crank no changes. Voltage at bottom wires in ignition harness, Red (constant) and with key on - White (transmission) and Orange? Not sure. Yellow wire gets voltage during ignition crank attempt.
12. Vehicle starts flawlessly via remote start with key in on position, wont start without key turned on, it tries three times with the same results as trying with key at ignition. Vehicle dies when brake is depressed (function of remote start system). Successful remote start brings following transmission codes - P0740, P0785, P1860
13. After watching MAY03LT's video I measured voltage at fuse 47 under rear seat fusebox while key is on - battery voltage at each side of fuse.
At this point I'm convinced it's the remote start, an ignition switch issue, or given the codes and the guidance in the video, a transmission solenoid.
Throughout the course of this headache I've swapped the new and old ignition switch 2-3 times trying different things. I lost track of the proper gear alignment from the switch to the ignition harness. Spent hours the other night trying different positions hoping to get a start. Mostly end up with key out and ignition positioned to off while accessories are still running. (Gauge illumination, battery light, stereo etc.)
Ended up calling the company that installed the aftermarket remote start years back, inquiring about how to take it out. The guy I spoke with assured me there's no security/alarm and no starter kill relay in this system, and that there should be no correlation... Though I wonder if the way they've wired it could be causing my issue now, mind you my mom had it installed 4 years back and it hasn't posed an issue in any of that time.
Finally last night as I spent a few more hours adjusting the positioning on the ignition switch I figured, "well I haven't jumped at the new starter yet". I've since saved and cleared the previous codes I got, so I figured I'd see if I get the same thing. Nope. Started right up (key in ON position) with no codes. Being as I wasn't as afraid of my transmission blowing this time I thought I'd try and take her for a ride. Drove around the neighborhood till operating temp, then took to the main roads and put a little strain on er. Nothing. No codes. Drove great. Yet still, no start.
Any idea's on what to pursue here? Appreciate anyone taking the time to give this a read/throw some guidance my way.
