Engine Not Cranking Over?

Its sounds like the BCM has gone bad, this is a common problem with GM. Please check it and get back to me ;-)

This guide can help as well

https://www.2carpros.com/articles/starter-not-working-repair

Please run down this guide and report back.

I tried to put a new stereo in my car not knowing the factory radio had an security system on it! Now my car wont fully turn over what do i need to do i have the new harness

the security means that the radio will not work in any other vehicle.

check your wiring as you may have blown a fuse installing the radio preventing starting

Roy

Electrical problem
2003 Oldsmobile Alero 6 cyl Front Wheel Drive Automatic

wiht the fuses and relays in place the vehicle will not crank at all. battery power at starter but no power to solenoid wire with key in start position. have confirmed power at relay for both the signal and the battery power for solenoid. bypassed the nuetral safety switch with no good result. was able to get the engine to crank with term 86 of the starter relay grounded which makes the car turn over with the key in the on positoin. seems to me that the pcm is not grounding the starter relay. has anyone had this issue. am i on the right track?

Sounds like you're on the right track -also see below

car will not crank in morning or when wet.

check for clean battery terminal ends and good connections. check battery including load test most places do for free. check grounds on engine and body from battery for good clean connections.

hello I have a Oldsmobile Alero 2003 it will crank but it wont start. the engine is turning over and the fuel pump hums but nothing happens. I recently had a new ignition switch installed maybe 3 weeks ago thinking that would solve the problem. Now the car won't start at all again. Do I need to replace the ignition module, ignition coil, or bcm? or what? losing money...not being able to go to work...please help!!! bg

Have you checked for codes yet?Also have you checked actual fuel pressure?Just because the fuel pump turns on doesn't mean its making the correct pressure.

*** I may need to add that it happens alot when its very hot outside.

So does anything else not work fuel gauge keyless entry door locks etc when there is no start? Also we still need to know if there is spark proper fuel pressure etc.

i dont even turn the car off until im at work or home so i cant afford to be stranded at the auto parts store. its really annoying not being able to go somewhere on a wheem. i thought the fuel pressure was cool though if you hear the hum.

Just because a fuel pump runs doesnt mean its supplying the proper fuel pressure.With checking for codes checking spark fuel pressure etc Its really hard to say what's going on.I would get a scan on the computers with a professional scan tool that can readcode on all the computers

My car cranks and cranks but wont turn over. Before I had the security issue and got that taken care of. Now it just cranks. Mechanic said needs to engine because the comprssion. But once i do get it to start it runs great. I can mess with the key in the ignition and I know when it will start because I can hear the fuel pump priming the other times it does not. PLEASE HELP!

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine at least 3/16 away from ground -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard it.

I have replaced the fuel filter, which I can hear power up, and the fuel filter. The car will not start, I have used starter fluid to see if it has spark and it does. I am at my ropes end here, help.

Thanks

So the engine DOES crank and run if starting fluid is used? Check the injectors and see if there is power to them, they make a noid light that plugs into the harness for this, but a test light can be used. If no power to the injectors check fuses and PCM power and ground. You can try a Passkey relearn if it's the security system.
Have you done a relearn on the pass-key?
GM PASS LOCK RELEARN- Ignition to "run" position, try to start and let key return to "run" position
Approx ten minutes security light will go off
Turn key "off" and wait 5 seconds
Repeat 2 more times for a total of 3 relearns.
Turn key off, then start it

My car will not start. However, the engine cranks but does not fire. I checked under the hood and there was two red wires connected with a fuse at the bottom of wires just lying underneath my hood between the alarm siren and battery. Should this red wire be attached and if so where? Could this red wire not being connecting be the culprit?? Please HELP!!

Try hooking it up to the battery positive post and see what happens-if it continues cranking and no start do below to determine if its fuel or spark.

Get a helper disconnect a sparkplug wire or 2 and ground it to the engine -have helper crank engine over-do you have a snapping blue spark? If so-you have a fuel related problem, check the fuel pressure to rule out the fuel filter/fuel pump/pressure regulator and listen to the injector/s are they pulsing or hook up a noid light. No snapping blue spark continue to troubleshoot the ignition system-power input to the coil/coil packs,coil's resistances,distributor pick-up coil, ignition control module, cam and crank sensors and computer Note: If it doesn't apply disregard

Thank you for your response. How do I hook it up to the positive battery post?? I know where the positive battery post is but how does the wire stay in place??

Attached is a picture of the red wire in question. Please explain how I connect this red wire to the positive battery post? Thank you.

Did you do my 1st suggestion if not do so and get back disregard the red wire at this time, Not familiar with that gadget

Thank you but I am confused. I thought the first suggestion was to connect the red wire(in the picture) to the positive battery post. Which I could not figure out how to do that so I sent the picture of the red wire. The other suggestions I have not tired because I just had a diagnostic and an inspection two days prior to my car not starting and everything checked out. So I thought that this red wire(in the picture) that I found under my hood on the day that my car would not start had something to do with my car alarm like the power wire for the car alarm or something and that it somehow got disconnected and is now preventing the car from starting. I don't know. What do you think?

car will not turn over does not need a battery, has gas. did the same thing last week sat for two days than strted up wit no problem> cuts off sometimes when i drive but will start back up.

hi, ok, we need to establish a few things, hopefully you have a friend that can help you with this, we need to establish if the fuel pressure is low and if you are having and ignition problem, so we need to check fuel and spark.....i'll send you info on how to do this

https://www.2carpros.com/how_to/how_to_test_an_ignition_system.htm

https://www.2carpros.com/how_to/how_to_check_fuel_pressure.htm