Expert: Roland Finston - 10/17/2011

Question
My alternator light would come on my chrysler sebring 2004 2.7 for a few weeks. then my car would start turning off whenever I was at idle. I then found out that it was the fuse blown. I would replace the fuse and keep going. Now it will shut the car off while driving b/c of the blown fuse. I have since changed the starter and the alternator light went off, but has since come back on and i still have the fuse blowing problem. Any suggestions?

Answer
Hi Naeem,
The alternator light will come on when there is a short circuit shunting current to ground in such a large quantity that the battery voltage is sucked down too low. There is a short in one the circuits that are supplied by the #8 fuse.
That fuse powers the basic operation for the engine electronics as well as the activation of the starter motor via the starter relay and then to the starter motor solenoid switch, and as well provides the power to the fuel pump.
My suspicion is that the fuel pump or the starter solenoid circuit is overdrawing the current limit of the fuse rather than the engine electronics because that latter set of functions all have secondary fuses that should blow first before blowing fuse #8. My thought is that the wire to the fuel pump or the pump itself is shorting because the starter circuit is not involved unless you have the key in the 'start' position/the start relay is stuck 'on' but you would hear the starter motor grinding if that were the case.
It would be most efficient and economical to troubleshoot the situation with a volt-ohm meter that shouldn't cost more than $20. You would measure the resistance to ground (the - post of the battery) of the downstream side of the fuse socket which would be the front side of the fuse socket. See what it reads in the off positon of the ignition switch, the run position, and start position. Which ever of those is a dead short (0 ohms) would then be evaluated according to the circuit diagrams of that device is in play in that position of the switch. Let me know what you find and we can go from there.
Another '04 Sebring owner asked the exact same question yesterday. It will be interesting to learn why both of you are having this problem.
Roland