Trailblazer wont start. Please help!

[TopwaterTom21]

Here goes...

A little background for what its worth...

I have a 2003 Trailblazer LT 4.2L 6-cyl with 115,000 miles on it. The fan clutch recently gave out on me making my car roarrr so I replaced that one with a new Dorman model (big mistake). The dorman gave out soon thereafter and after many hours on google I found that Dorman's are known to malfunciton so I changed it with a Hayden and its been running smoothly.

Anyway, I had a check engine light on that I want to try and get rid of, I already know it's because of a temperature senser, so I disconnected my battery to try and clear the codes and I started my car up and it fired up and the check engine light went away. I drove around the block and came home turned it off. Tried to fire it up again and nothing. Wouldn't even turn over. It makes a click like it's trying to and it makes a small noise that sounds like a relay opening up but thats it. The radio works, the gauges come on, but when I try and start it or roll down the window everything shuts off except a flickering check engine light. I've been reading around trying to figure it out and the only things people have mentioned are a bad ignition switch or maybe a passlock from the security system. It's not an aftermarket system and no car starter. Everything is standard. I've check all the fuses and yes the battery is tight and the connection is good with no corrosion, yes it is fully charged. Any ideas? You're help will be greatly appreciated.

[jeffreyd]

sounds like a bad battery to me or a loose cable since you took them off. make sure you did not connect them wrong. removing the cable wont remove the code, only cycle the light until it sees the issue again then will turn on the light.

[Macgyver55]

Make sure the cables are tight on the battery as said.

Do you have a blinking "security" light? That would indicate a Passlock problem.

[TopwaterTom21]

I have double checked the battery and all seems well. I don't have a blinking security light and I kind of ruled that out. I drove home from work just fine before this happened. Could my battery still be bad?

[TopwaterTom21]

Thinking I may have had a dead battery for some reason I had it hooked up to the charger for the last few hours. I went out and tried to start it and still it wouldn't turn over. When I had the key in the on position I could hear clicking in what sounded like the fuse box but couldn't tell. I'm starting to think maybe I could have damaged my starter or starter selenoid?

[Macgyver55]

I'll say battery. Many of the relays and such will make noise when the battery is low. Try jumping it or try a battery from a different vehicle.

[Jeremy airjer W]

I agree you need to take a look at you battery cable ends. Either there loose, corroded, or the terminals in the battery itself have come loose from the battery when you disconnected and reinstalled. I have run into that several times on the side terminal batteries.

When everything goes dead that tells me there is a good enough connection to power up a small load. When you try to start there is an extremely heavier load on that connection. It gets hot, opens up the circuit and everything goes dead until it cools off. Then everything starts to work again.

Surprisingly enough I see this scenario more on fords than anything.

[lichen fox]

I had the same problem on my blazer...turns out to be the battery...I had a dual terminal and when I checked it with my meters it all checked out...top and side terminals...when I re-hooked up the side terminals to the cables I once again lost power...put adapters on, and hooked up to the top posts and everything worked fine...the positive side terminal was corroded or partially broken off inside the battery...when the cables were tightened, it broke the connection inside the battery....