engine will not turn over

Good afternoon,

I attached a wiring diagram for you to view.

Do you have a test light or voltmeter to do checks on the starting system?

https://www.2carpros.com/articles/how-to-check-wiring

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Roy

Yes I do. I have also been advised that it could have something to do with security system? When I turn the key on, the icon for that stays lit. I don’t know if it’s supposed to though.

Okay, it should go out after about 10 seconds. Does it do that?

I attached a guide to reset for you to try as well.

https://www.2carpros.com/articles/how-to-reset-a-security-system

Roy

The security stays on as long as the key is on. I will try the reset steps you sent me.

Okay, sounds good.

Keep us updated with the results.

Roy

I tried all the steps you forwarded to me and they didn’t work. I left the battery disconnected overnight, still nothing. I turned the key in this morning and after just 2 or 3 minutes, it started doing this (see video). As of now, the security light is not on, but it still won’t turn over.

Okay, I could not hear a thing. What was being done during that video?

Roy

I was just sitting with the key in the on position. The security light and a couple other lights started flashing rapidly and then the security light turned off. It was staying on and solid (not flashing) before this occurred.

Okay, does the engine crank over now?

Roy

Okay. The security light has gone out. I’m not getting power to the solenoid. Battery is fully charged. Checked fuses, all good. Swapped relays around. Still nothing.

Okay, you need to go to the relay.

With the key on, remove the relay and test for power at one of the pins. You should have 1 pin with power.

Then have someone hold the key to the start position and there should be power to another pin.

I posted the wire diagram in my first response.

Roy

I am getting power to two pins with the key on and when turned to start position.

Okay, with the key on, only one should have power. The second power should only be there when the key is in the start position.

Okay, install the relay again. Have someone turn the key to start and see if the relay clicks.

Roy

Yes it does click.

Okay, the control side is working.

Go to the starter itself and the little wire on the solenoid. The little purple wire should have power in the start position.

If it does, you need a starter motor.

If it does not, then you have a wiring issue between the fuse block and the starter solenoid.

Roy

The wire to the solenoid doesn’t have power. I also want to note the start fuse next to the relay doesn’t have power to it either.

You stated you had 2 powers at the relay, one in the start position. If you did have that power, then it passes through that fuse. That fuse is only hot in the start position.

If the relay clicked, power has to go through that fuse.

Roy

Okay. I didn’t know that, so I wanted to point it out.

I would have gone there if you had to power to the relay in start position.

Roy

Just re reading some of your responses. Relay has two pins with power whether the key is just on and in start position both.

I’m leaning towards the problem being in the fuse block itself. Would you think the same?

If the relay energizes when you turn to start, the control side is working.

Did you verify no power to the purple wire at the starter solenoid?

Roy

Relay has two pins energized in start and on position. No other pins energize when in start position.

There should not be any power on the other 2.

We are beyond that now and working on the purple wire to the solenoid.

Again, if you have no power to the solenoid, and the relay is clicking, you have an open in the purple wire from the relay to the solenoid.

Roy

10-4. Will let you know what I figure out.

Sounds good.

Keep me updated.

Roy

Yesterday after I got home from work, just for grins, I tried starting the car. All the warning lights in the dash came on as expected, including the security light. It went back out as it should. When I tried turning the key to start, the security light began flashing rapidly, just like it did in the video I sent you a couple days ago. I’m thinking the issue may still be with the security system. Thoughts?

Yes, I agree.

Can you check for any codes set and did you try the reset for the system?

https://www.2carpros.com/articles/how-to-reset-a-security-system

Roy

Code reader shows no codes. I erased codes after fixing an overheating problem. I did go through the steps you sent me for resetting the security system. But I will give them another try and let you know the results.

Okay, keep us updated.

Roy

So, it ended up being the ignition switch... I appreciate all the guidance I’ve received from y’all.

Good deal.

Glad it is fixed.

Always glad to help.

Roy

Hello again, I’m back to having an engine that won’t turn over. Security light stays on solid when key is in on position. No power to relay or starter fuse. Reset steps you sent me a while back have no effect. Last time, I replaced the ignition starter switch and it fixed the problem. This time, as of now, I’ve replaced the key cylinder and put another ignition starter switch in. Starter fuse isn’t blown. Relay has continuity across 2 points. But no power getting to them at all when key is turned on.

Okay, can you check for codes again and see if anything is set?

Roy

It was registering an engine misfire code. But I replaced the plugs and plug wires and that stopped that problem. Now it’s showing engine speed input circuit no signal (P0727) and crankshaft position sensor (P0335).

Okay, the 727 code has only 1 result. You need a ECM. It has failed. You need to replace that first before looking at the 335. The 727 could take care of that code as well.

It also take care of all you other issues.

Roy

Ouch!! Okay, how difficult is it to program to the vehicle?

You need an advanced scan tool with access to GM technical web site to download the software.

Otherwise, you need a shop to do this for you.

Roy

Alright. I figured as much. I appreciate your help.

You are welcome.

Always glad to help.

Roy