car wont start

[excessive81]

Hey guys have weird issue. Put my 250 amp alt on today and when went to start it after, nothing happened. Security light is flashing. When unhook the battery and reconnect the key fob functions ect until try to start. Then the lights stay on...fuel pump runs and security light is flashing and key fob no longer will open trunk or lock/unlock doors. I put new stereo in a month ago have had no issues. Have had battery unhooked before and never had this issue and used all the modules etc. Battery was unhooked about 3 hours while installing the alternator. Battery is charged but did try booster box and battery charger before giving up. I have had a 2000+ Bonneville for 7 or 8 years but never seen this. Has anyone seen this before?

[CMNTMXR57]

What in the world do you need a 250amp alternator for? the stock 140 isn't enough?

Anyway, there is a short somewhere causing a battery drain due to the aftermarket equipment. Had it started and ran, there is also a low regulator voltage issue due to aftermarket alternator on the same notice...

[excessive81]

My amps draw 160 amps. And car has been fine until now. The amps are not hooked up. Only thing that is s hooked up is the head unit which has been for over a month. And battery is not low

[CMNTMXR57]

Good grief, can you hear anything after listening to that?

Anyway, hard to diagnose electrical issues in person, much less over these. Sounds like there is a sufficient voltage drop in the system, causing a Class 2 communications issue.

[excessive81]

Yes it is crystal clear but can get stupid loud lol. Yeah I think I gonna try swapping the old radio back in. I holding then security system is the issue ....fingers crossed

[excessive81]

radio swap did not work....

[00Beast]

Did you properly re-connect the connections at the alternator? Whenever you do something and the car doesn't work, it's time to re-assess what you just did....

Might try swapping the stock alternator back on for your next test. Make sure all the contact points are clean and bare metal, so the alternator gets a good ground contact.

[excessive81]

Yes triple checked everything before left the car where it was.....I at a loss. Battery tested good but low so put on charger but don't see that as issue because it didn't even try to start

[myfirstbonnie]

That is why it was mentioned about the class 2 bus. If the battery is low, it won't even try to start. Been there when my original battery was bad. It would check good with a meter, but car would not start if it was left setting for 2 days.

What battery do you have? Is it the original AC delco?

[excessive81]

No optima red top and charging it up did not help. I put jump box on it and a a charger on last night amd today but no change. The security light is flashing as soon as unlock door though as well as after turn key on

[00Beast]

Optimas can be weird trying to recharge. More info: http://www.hotrod.com/techarticles/gene ... ewall.html

[excessive81]

Battery is at 12.6 volts and holding

[myfirstbonnie]

Do a load test on the battery and if it checks good, then check for a drain or short on the car. Make sure the alternator leads are not shorting anywhere.

[excessive81]

OK well found it. The ground had came apart that is held in with the side bolt in alt. Found it when was pulling it apart agian to change back to old alt. Fixed ground and all is good....

[00Beast]

I figured it had to be something that simple. Glad it was an easy fix.