Replaced headlight bulbs and now car will not start

Tiny
JEFFREY BOONE
  • MEMBER
  • 2005 CADILLAC CTS
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 118,000 MILES
Replaced the headlight bulbs in my car. Did not disconnect the battery, put the bumper back on. All lights and systems work however when I crank it it turns over and almost starts but will not run. Symptoms similar to being out of gas. Drove fine the night before the headlight change. Shows 1/4 tank of gas. I even added a gallon to be sure. Where do I start trouble shooting?
Do you
have the same problem?
Yes
No
Saturday, February 8th, 2020 AT 11:57 PM

1 Reply

Tiny
KASEKENNY
  • MECHANIC
  • 18,907 POSTS
We need to start by go back over what you removed and see if there is any chance something is still unhooked.

Then scan for codes. Hopefully there is a code that will give us something to go on.

If there are no codes then we will have to start eliminating things. The first thing is to spray starter fluid in the intake and see if the engine fires. If not, then we need to remove a spark plug and connect it back to the ignition system and hold it against the block to see if it sparks.

The purpose of this, is you need three things to fire an engine. Spark at the right time, fuel, and compression. We can assume that the compression is okay since it was just running and nothing dramatic seemed to happen. However, we may have to come back to this if nothing else pans out.

https://www.2carpros.com/articles/car-cranks-but-wont-start

https://www.2carpros.com/articles/engine-cranks-excessively-before-starting

Here is more information to help you:

If your 2005 Cadillac CTS won't start after replacing the headlight bulbs, there are a few possible causes for the issue. Here's where you can start troubleshooting:

Check for Loose or Disconnected Wires: Start by inspecting the area around the headlight bulbs where you performed the replacement. Make sure all wires and connectors are properly secured and connected. It's possible that during the bulb replacement, a wire may have been inadvertently disconnected or damaged.

Verify Battery Connections: Even though you didn't disconnect the battery during the headlight replacement, it's still worth checking the battery connections. Ensure that the battery terminals are clean and tightly secured. A loose or corroded connection can prevent the car from starting.

Scan for Error Codes: Use an OBD2 scanner to check for any error codes stored in the vehicle's onboard computer. Even if the Check Engine Light is not on, there might be pending codes that could provide valuable information about the issue.

Check Fuel Delivery: Although the fuel gauge shows 1/4 tank of gas, it's possible that there may be a problem with the fuel delivery system. Check the fuel pump, fuel filter, and fuel pressure to ensure that fuel is reaching the engine properly.

Inspect Fuses and Relays: Check the fuses and relays related to the engine and starting system. A blown fuse or faulty relay could be preventing the engine from starting.

Security System Issue: Some vehicles have a security system that can cause starting issues if it becomes activated inadvertently. If your Cadillac CTS has a security system, make sure it is not engaged.

Timing Belt/Chain: If the engine turns over but does not start, it's possible that there may be a problem with the timing belt or timing chain. A broken timing belt/chain can cause engine misalignment and prevent the engine from starting.
Was this
answer
helpful?
Yes
No
Sunday, February 9th, 2020 AT 1:35 PM

Please login or register to post a reply.

Sponsored links