Chrysler 300C & SRT8 Forums banner
1 - 4 of 4 Posts

·
Registered
Joined
·
11 Posts
Discussion Starter · #1 ·
I have a 2005 Chrysler 300c 5.7l hemi, i have a constant indicator on my dash... the battery light. I have changed the battery, the alternator and the serpentine belt without relief. Over a short period of time the battery will drain and engine wont start. I get no trouble codes. Please help! Any direction or advice would be GREAT! So frustrating.
 

·
Registered
2006 CRD Touring
Joined
·
2,840 Posts
Before changing so many components, you should have checked some voltages on the EVIC.
A fully charged battery on light load should have 12.6V, with engine stopped.
With engine running you should have 14.6V.

How are you re-charging the battery after it drains?

If your warning light comes on, there should be a trouble code stored. What are you using to scan for codes?

If a fully charged battery is draining when parked, you need to check for any accessories, eg interior lights - particularly trunk light, which may have been left on.
 

·
Registered
'05 300c Blondie
Joined
·
173 Posts
This thread might be of interest.

"... -ve to ground and a field control wire connected to the ECU. It is the ECU field connection which provides fine control over the alternator output. It is not uncommon for this field wire connection to be overlooked when installing an alternator"

Also, hold down the compass & music note buttons on your steering wheel. It takes a few seconds, but another menu should come up on the evic... arrow thru and you'll find a screen which shows the speed, rpm's, temp & voltage. You can leave this up while driving to monitor
 

·
Registered
Joined
·
134 Posts
These cars have a voltage reg of sorts in the car processor/CPU (or one of the control modules); and if that is not working, the alternator can't work.

If your battery is ok, draining means you have a drain to earth. But there are two other things you need to do before you do that.

As said above, see if the alternator is charging. Either use a voltmeter, or use the EVIC (display) as Grumpy says. Approx 12.6 with key off for fully charged battery, and then should jump to between 13.5 to 14.5 volts when running. If it does, then load it; rear window demister/heated seats/lights on with high beam. Then check again. If it is above 13.5 unloaded, but then drops below when all that stuff on, then alternator output is down.

You say is a new battery, but easy to test. Fully charge it (smart charger goes over to "float") then load test. Cheap load testers are $15 (in the US) and handy.

Once you know that battery is ok (should be, it is new) and that alt O/P is correct; THEN can look at drain/connections.

I have had so many people come to me with "can't be battery/alt related, it's a new battery/alt"; and it has been connection related. People don't understand connections, they think they are connected/or not. But with 130 amps max going through alt lead connection, and 300 going through batt connections, just a few ohms make ALL the difference.

You need a wide/clean current path for high current, and many don't get that.

(Sorry, basic electrics 101 is boring, but people often overlook it.)

BE CAREFUL - if you are going to clean the alt connection, it is always live/connected to battery, and any short will do major damage, so disconnect battery first. Again, sorry if suck eggs.

Cheers.
 
1 - 4 of 4 Posts
Top