Need help, no crank/no start and blinkers on

[CakeBlazer]

2002 Trailblazer LTZ.

Full story - Started having issues a couple months ago. One day had no power at all, key stuck in ignition until the electrical system seemingly reset itself and the alarm started going off. Was then able to remove key from ignition and start car. Didn't happen again.

One day a few weeks later the car wouldn't start at all. Replaced ignition switch which seemed to solve issue, car started fine multiple times, but the low fuel light was staying dimly lit on my instrument cluster. Concerned with this I pulled the cluster and desoldered the light, damaging one of the stepper motors when I pulled its needle.

So I stopped messing with the cluster and sent it to GM Gauge Repair for a full rebuild and just got it back and reinstalled in the car. Car is now not starting or even turning over. Absolutely no noise when key is turned to start.

In addition as soon as the battery is connected all blinkers (turn signal lights) and the signal arrows on the dash turn on and blink, and the radio display is on. Nothing stops this behavior, it continues until the battery is disconnected. Instrument cluster and all other displays seem to be functioning properly though.

Minor note, back-lighting for the gas, battery, temp, and oil pressure gauges turns off along with the climate control display and steering wheel controls back-lighting when turning the key to Start and remains off until moved to Run/On position.

What's the problem here? Alternator? Starter? Starter relay? Something else entirely? I need this car running in a couple days, need to solve this.

 

[Mooseman]

How old is the battery? Did you have it checked? A weak battery can cause all sorts of weirdness.

What brand ignition switch did you use? Some aftermarket ones can fail prematurely.

 

[CakeBlazer]

How old is the battery? Did you have it checked? A weak battery can cause all sorts of weirdness.

What brand ignition switch did you use? Some aftermarket ones can fail prematurely.

Battery was purchased and installed in June of 2017 after my last one died.

Battery voltage jumps up and down between ~12.05 and 11.90 but the blinkers are going and the radio display is on. Averages 11.90 with key in on position. I have not had it checked more thoroughly beyond checking voltage myself. It was charged once during the process with my initial problems (before ignition switch replacement) to see if that would change anything which it didn't.

Ignition switch is a NAPA Echlin and is still practically brand new, the car wasn't driven with the switch in due to the problem with the fuel light and my subsequent removal of the cluster, that all went down in the span of a few hours. It was just started a few times after replacing the switch.

 

[CakeBlazer]

Well something interesting just happened.

After reading this thread I decided to go check and see what other electronics were working/not working. So I reconnected the battery and turned the key to On. Tried the driver and passenger windows to see if they were working and they were.

I then tried starting the car again and it cranked and started. Start up was a bit rough when it was firing up but running appears fine. Instrument panel went from "Unknown Driver" to "Driver 1". All electronics appear fine, gauges working properly. Engine revs as it always has, it shifts fine, etc.

Problem - the blinkers are still on. They remained on all through what just happened and remained on after turning the car off and starting it again (yes, I go it to start twice). Battery has been disconnected until this is solved.

Also took the opportunity to check running voltage, running voltage varied a bit but averaged 14.75 volts.

So, ideas?

 

[mrrsm]

The Turn Signals AND The Emergency Flashers are handled by One Single Module. Remember that the Emergency Flashers are designed to function when the Engine is OFF. So if that Module Bread-Board happens to Short Circuit internally... it may still be drawing power with the Key Off as though the Flashers were intentionally Turned ON:

 

[Blckshdw]

You may have already checked this, but can you confirm the hazard flasher button on top of the steering column is deactivated? I know a number of times when I've disassembled the dash, I've bumped that button by accident.

 

[CakeBlazer]

You may have already checked this, but can you confirm the hazard flasher button on top of the steering column is deactivated? I know a number of times when I've disassembled the dash, I've bumped that button by accident.

Woooooow. I feel sooooooo dumb right now.

That was it. Thanks. Still no idea why it had trouble starting earlier. We'll see if it behaves from now on. For the record I started it again just now after checking that, seems fine.

 

[16vcabman]

I was just thinking about that button on the top of the steering column. I think your ugly nostart is going to rear it's ulgy head soon.

 

[Mooseman]

Maybe a poor connection at the battery terminals and reconnecting it cleared it up. Like I mentioned, bad battery (i.e. bad voltage) causes all sorts of weirdness. Maybe have the alternator checked as a last thing and that should be it.

A new battery means nothing. I've had a bad battery that couldn't start after 3 months. Never eliminate a new-ish part as it can be defective.

Glad you got it sorted out.

 

[DocBrown]

Battery voltage jumps up and down between ~12.05 and 11.90 but the blinkers are going and the radio display is on. Averages 11.90 with key in on position.

Glad to hear it's working now. However, have you checked the battery with the ignition off after it's sat for at least 10 minutes? It should read 12.7 or higher. If it's lower it can cause all kinds of weird havoc. As Mooseman said, don't trust it just because it's not old.