Please help...won't start

[Comptons04LS]

I drove the ls home from work and parked it then came back out to leave and it won't start. The battery is fully charged and the fuses are good. The car won't even turn over...no radio lights my key fob won't even work. Any suggestions on what it could be?

 

[stugots]

How do you know your battery is good? Is the pats light blinking on the top of the dash?

 

[Comptons04LS]

I tested the battery with a volt meter

 

[Comptons04LS]

And I have no power of any kind

 

[stugots]

A volt meter won't tell you if your battery is good.

 

[joegr]

I tested the battery with a volt meter

Open circuit battery voltage tells you very little about your battery. It needs to be load tested.

I assume that no lights come on, not even the light in the trunk?

How do you know the fuses are good? Did you test them, or just look at them? Did you check all the fuses in all three fuse boxes? Did you check the battery cables and clamps?

 

[Comptons04LS]

Yes I have checked all the fuses in all 3 locations and I also checked the relays.

 

[Comptons04LS]

And yes your correct...I have no lights at all

 

[joegr]

Battery or main cable.

What is the voltage at the battery with the car battery cables attached? (Trunk open, of course.)

 

[Comptons04LS]

12.8

 

[joegr]

12.8

If you have 12.8V at the battery, all of your fuses tested good (not just looking at them), all of your relays tested good, and your battery clamps and cables are good, then your problem is impossible.

I suggest that you didn't really test all of these things.

Next test, measure voltage between a piece of unpainted metal in the trunk (one of the ground points is good for this, but don't use the battery cable ground point), and one of the main fuses in the trunk fuse box.

 

[Comptons04LS]

I ohmed all of them

 

[joegr]

I ohmed all of them

There is, of course, no way to completely (or even mostly) test a relay with just an ohm meter. You would have to power the coil to test the normally open contacts.

Anyway how about the voltage measurement I asked for? (It's to verify the battery cables and clamps.)

Something is wrong (your car has no electrical power) so something is wrong. If nothing is wrong as you say, then it's a localized disturbance in the laws of nature, or it's a supernatural event. I can't help with either of those.

 

[stugots]

then it's a localized disturbance in the laws of nature, or it's a supernatural event. I can't help with either of those.

Made my night haha.

 

[chocolat1701]

take the battery to autozone and have them tested also clean the contact ends even though its in the trunk it should not get any dirt on them. or just get another battery from autozone and save the receipt if the car does not turn on with the new one then its not the battery even though all indications says it is. also did you even try to jump the car. if you atleast try to jump it and the lights come on then you know its the battery.

 

[Comptons04LS]

Ok I let the battery charge for 4 hours last night. I hooked it back up and still have no power at all. I have checked the fuses and relays and the only blown fuse fuse was for the cig lighter. I just hooked up jumper cables from my tahoe to the ls and still have nothing at all. Going to recheck all fuse and relays again to see if I might have missed one. But if all fuses and relays are good, could it be the ECM or the ignition module? But say the ignition is bad, wouldn't the dome lights and trunk light come on when the doors are open? And when checking the relays I was told from a previous post the circuit needs to be open. Can I do that with a jumper wire?

 

[joegr]

How about we go one step at a time and do proper trouble shooting?

Next test, measure voltage between a piece of unpainted metal in the trunk (one of the ground points is good for this, but don't use the battery cable ground point), and one of the main fuses in the trunk fuse box.

 

[purevilpleasure]

I'm going to make a big jpeg that says something in the fact....

Listen To Joegr...save yourself some trouble!!!

 

[immusicman]

I'm going to make a big jpeg that says something in the fact....

Listen To Joegr...save yourself some trouble!!!

I agree, listen to Joegr because you must test to see if you have a ground from the battery to the chassis and if so then you can move on to tracing the positive cable connections. I promise you if you follow the proper troubleshooting as he is directing you, you will find the problem.

 

[Comptons04LS]

I tested one main fuses to a diff. ground and it's reading 2.6 volts with the key off

 

[joegr]

I tested one main fuses to a diff. ground and it's reading 2.6 volts with the key off

Okay, so somewhere between the battery and the trunk fuse box, you have a bad cable or connection. Lets find out where.

Test for voltage between the "diff. ground" and the negative post of the battery. If you get a reading over 0.0, then your battery ground cable is bad or is loose. Remove it and clean or replace it.

Or, if that read zero, test for voltage between the positive battery terminal and that same main fuse. If you get a reading over 0.0, then the problem is the positive battery cable, a loose connection at either end of it, or it's in the trunk fuse box itself. If you keep measuring between different parts along the circuit (same node), you'll find it.

 

[Comptons04LS]

Thanks for your help! It was a bad ground from the bAttery. It was were the car had been rear ended and I had it fixed and they painted where the ground was connected to the car!