Will not start?

Hi,

Does the starter engage and turn the engine or does nothing happen? Also, is the security light staying on?

If the starter is engaging, try this. See if the engine starts with starting fluid. If it does and then stalls, we know it is a fuel-related issue. If there is no change, then it is likely ignition related. At that point, I suggest checking to see if there is spark to the plugs.

Here is a link that explains how that is done:

https://www.2carpros.com/articles/how-to-check-for-ignition-spark

Let me know if that helps and exactly what is going on. I will do my best to help.

Take care,

Joe

Good morning. The starter does not engage and the security light is off.

Hi,

No problem. Do you hear any noise such as a clicking sound from the starter? Does it start if you place the transmission in neutral?

If your answers are no, to both questions, we need to trace things to determine where power is lost.

I attached the wiring schematic below for the starter circuit. First, I need you to check the three fuses that I highlighted. In addition to checking the fuse, confirm there is power to and from it.

Here is a link that explains how it's done:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

If the fuses are good and have power both in and out, then I want you to switch the starter relay with a different one in the box having the same part number to see if it makes a difference.

If there isn't one, here is a link that explains how to test a relay:

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

Let me know what you find or if you have questions.

Take care,

Joe

See pics below. Note: Pic 3 shows the fuses and relay to check in the under-hood fuse box.

Good evening. No starter clicking nor is the shift interlock releasing when I press the brake pedal, so I can't place the transmission in neutral.

Hi,

Okay, then we need to check the fuse I mentioned. Also, and don't laugh, do the brake lights work? I ask because the shift interlock solenoid is actuated by power from the brake lamp switch. Check to see if they are working.

Joe

Good evening again. No power to fuse 17 but fuse 34 and 22 have power to both sides verified by a digital test light. And the brake lights are working.

Hi,

When you checked power at fuse 17, was the key in the start position? If that is the case, the problem may be the ignition switch.

Let me know.

Joe

Good evening, key was in the run position but not the start position. I will have a helper assist me in the morning and I'll reply back to you. Thank you and enjoy your evening.

Good morning. Fuse 17 has power coming to and out once the key is in the start position.

Hi,

Okay, we have a power supply from the battery everywhere it is needed. Next would be the starter relay. It is in the under-hood fuse box. Remove it and switch it with a different one in the box having the same part number.

If there isn't one, here is a link that explains how to test one:

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

If you have already tried this, then go to the starter motor and locate the purple wire. That is the smaller gauge wire and is the trigger wire. It has no power unless the key is in the start position. Have a helper turn the key to the start position and check if the purple wire has battery voltage.

Let me know what you find.

Take care,

Joe

Good evening. I have no power at the signal wire on the starter when the key is turned. Also, still no key/cluster chime while the key is turned.

Hi,

Have you checked the relay and the relay power supply? If you remove the starter relay, there should be power all the time to one of the pins and another one that only has power in the start position.

We must be missing something simple. Everything that should have power does. Other than the ECM isn't providing a ground path for the relay to complete the circuit.

Let me know about the relay.

Joe

See pic below.

Good morning. I have 12V at fuse 34, 12V at leg 30 on the starter relay ,and 12V at fuse 17 when the key is in the start position. Fuse 22 has roughly 5V at all times.

Fuse 22 should have 12v when the key is in the run or start position. With the key off, there should be no power.

Do me a favor. Turn the key off. Confirm there is 5V to that fuse. If there is, remove the fuse. Turn the key on the run position and with the fuse removed, check one connector at a time to see if both have power.

Let me know.

Joe

Good evening, sir. My apologies, fuse 22 doesn't have power when the key is off. And it has 5V with the key in the run position.

Hi,

The fuse should have 12v. I suspect there is a poor connection under the fuse block. Are you comfortable checking that? My guess is It will either be at the fuse block or the supply or at the ignition switch.

Before we jump into checking wiring, do me a favor. I need you to check the pink wire on the neutral position switch. See if you are getting 5v there with the key in the start position. Also, check fuse 16 in the under-hood fuse box and see if it is getting 5v as well.

The circuit starts with the ignition key. It runs through several different fuses. I'm trying to see where the loss of power may be. Actually, power to the ignition switch for these circuits starts at both the ignition A (34) and ignition B (36) fuses in the under-hood fuse box. It is likely you have already checked fuse 34. Check fuse 36.

I'm sorry for the confusion. They have power running in all different directions. Let me know what you find. Also, make sure to check fuse 36

Take care,

Joe

see pic below.

Good afternoon. Where is the pink wire in question located? Is it on the transmission or on a fuse block?

Hi,

The PNP switch is on the side of the transmission. I wanted to confirm there is power to it.

I attached a pic below. Let me know if this helps.

Take care,

Joe

See pic below.

Good morning, sir. I need to verify if 5V is present at the pink wire with the key in start position, correct?

Hi,

Yes, that is correct.

Let me know what you find.

Joe

Good afternoon. I don't see a pink wire in that harness. Just to verify the vehicle is a 2006 trailblazer with a 5.3 and 2WD transmission.

Hi,

That is the correct vehicle. The wire could be faded. Is there anything there that appears it may have been pink?

Sorry, I know this must be frustrating.


Joe

I will check all the wire that resemble pink and report back to you with my results. Thank you

Good afternoon. There isn't power going to the pink wire.

Have you checked fuse 22 in the under-hood fuse box to make sure it is good and there is power to and from it? See pic below

Also, here is a link you may find helpful:

https://www.2carpros.com/articles/how-to-check-a-car-fuse

Let me know.

Take care,

Joe

See pic below.

Good afternoon. There is roughly 5V going to and from fuse 22 under the hood. Also, there is 5V only going to 2 wires on the neutral safety switch with the key in the run position.

Hi,

You should have 12v or battery voltage. Is the battery fully charged and in good condition?

Let me know.

Joe

Good evening, battery is fully charged at 12.6V.

Hi,

If the battery is fully charged, then we have a connection issue. If you remove fuse 22, check to see if there is corrosion, damage, or if a pin was pressed in and not making contact.

If it is in good condition and you only have 5v at the fuse, we need to disconnect the battery and remove the fuse box to inspect it from the underside to make sure there isn't a wiring issue.

Let me know your thoughts.

Joe

Good afternoon, to remove the fuse box I unscrew the three 7mm bolts and unsnap it correct?

Here are the pics of what I came up with. I really appreciate all your help

Hi,

It's hard to tell in the pics. Do you see any evidence of corrosion? Also, is the wiring in good condition?

Let me know.

Joe

I don't see any corrosion. I will peel the wire loom back tomorrow and check the wires.

Hi,

If the connector pins are good, I need you to check the power to the connector wire on both sides of the connection to see if there is a drop in voltage or if there is low voltage going to it.

Let me know.

joe

Would you mind sending me a diagram of which pin(s) to check?

Hi,

I attached the connector pin info below. You are looking for connector 2, pin B6.

Take a look at what I attached and let me know if it helps.

Joe

See pics below. Make sure to check the box where that pin connects. It should be easy since it is near the bolt hole.