C-5 wont start, no power to anything

[dadaroo]

Assuming they did a load test and the battery is good, then you have some kind of MAJOR battery drain/short going on. When you connect the battery you should get a small spark at hookup on the final/last connection. If you are getting a BIG spark something is really wrong. One thing big enough to cause this type of drain would be a short in the starter.

You might want to try and disconnect the starter and see what happens.

 

[Pags]

Im about to re connect the new battery up now. Reads 12.46v from my voltmeter. Ill post what it reads as soon as i hook it up

 

[Pags]

12.38 as soon as i hook it up

 

[Pags]

Youve got to be shitting me! It was the damn battery the whole time! It cranked right over but i didnt do it long enough to fire up. Im gonna put the dash back together first. Ill post back in a few mins

 

[LLC5]

12.38 as soon as i hook it up

Your fine so far. See if everything works now.

 

[Pags]

Well my 6 month old daughter decided to take a nap now, and the garage is directly under her room. So im gonna have to wait a while to try and start it up

 

[Toms007]

Sometimes it's the simplest of things.

 

[LLC5]

Well my 6 month old daughter decided to take a nap now, and the garage is directly under her room. So im gonna have to wait a while to try and start it up

I know that scenario all too well. I used to roll my Harley down the driveway to the street to start it (opening and closing the garage door VERY slowly). I have also been known to push my Vette (driver door open, pushing with left foot, making sure not to hit the garage with my open door) out of the garage before starting. Makes life interesting.

 

[Pags]

Hahaha, and i thought i was the only one who had to do that!

 

[Pags]

Well I tried to start it but it wouldn't fire, still doing the same thing as before. Checked the DTCs and everything says no Comm.

 

[Pags]

So it has power and will crank now, it just won't start.

 

[Pags]

So im still at square 1 as far as the no comm issue. (Which is what made me take the ignition apart in the first place). Everything is saying no comm in diagnostic mode. Battery is brand new, load tested, and good, Every fuse is good, every ground checked, star connector for doors&seats is disconnected to rule that out, and ignition switch contacts are clean. When i turn the key to "on" there is a slight 2 second hesitation for the display to turn on that isnt there during normal operation, also once i remove the key from the ignition completely the display is still flashing service engine soon, low fuel, trans fluid and all that. Any ideas on what it could be?

 

[Pags]

So after some messing around i noticed that the ignition relay under the hood was buzzing like crazy when i turned the key to the on position, so im gonna get a new one in the morning to see if that solves the issue

 

[dadaroo]

Please provide what it shows for each of the module designations unless you are saying every one of the 11 modules says no comm.

Once I get that I can recommend how to proceed.

 

[Pags]

Every single one says no comm. Would that buzzing ignition relay mean I may have a ground issue?

 

[dadaroo]

OK, did not see your earlier post, just the email update. Since you know how to access the star connectors I recommend you pull the tops of off both at the same time. Then jumper just the PCM and the BCM together and see if it will run. Those two wires are Dark Green and Light Green wire colors.

 

[Pags]

Awesome. Ill try that as soon as i get home from work

 

[dadaroo]

Every single one says no comm. Would that buzzing ignition relay mean I may have a ground issue?

Could be. Low voltage can cause that and a bad ground can create a low voltage.

Here is a list of all the grounds and what they serve.



Ground locations - Corvette Forum

 

[LLC5]

So im still at square 1 as far as the no comm issue. (Which is what made me take the ignition apart in the first place). Everything is saying no comm in diagnostic mode. Battery is brand new, load tested, and good, Every fuse is good, every ground checked, star connector for doors&seats is disconnected to rule that out, and ignition switch contacts are clean. When i turn the key to "on" there is a slight 2 second hesitation for the display to turn on that isnt there during normal operation, also once i remove the key from the ignition completely the display is still flashing service engine soon, low fuel, trans fluid and all that. Any ideas on what it could be?

What exactly is disconnected?

 

[Pags]

The only thing i disconnected was the star connector for the doors and seats. Im going to jumper the pcm amd bcm together later from the other star connector as dadaroo suggested to see if that sovles the issue