Need help: 300E won't start
 

Hi everyone. After it had been sitting for a couple of weeks, yesterday my 300E wouldn't start. Turned the key, got unpleasant clicking noises from the engine compartment, and nothing happened. Thinking it was the battery I pulled it and put it on the charger overnight.

After the charger indicated the battery was ready, I reinstalled it this morning and had the same thing happen -- turn key, unpleasant clicking noises, car doesn't start.

All of the electrical accessories work fine with the charged battery; it's just that the car won't start. I also tried jumping it but that didn't work either. I suspect the battery is good enough to run accessories but not powerful enough to start the car, so I'm thinking a new battery is in order. Any thoughts/suggestions before I go out to try and find a battery on a Sunday?

Thanks,
Mike

I'm assuming the car started normally before this two-week layoff.

If jumpstarting didn't work, it's probably not the battery. ..probably..

So ... first measure the voltage. If the charger indicates it's full, it should be 13V+. If you can, have a voltmeter on so you can read it while attempting to crank (the dreaded clicking noises). If it drops below 11V, it may well be dead. If it stays up, you may have either a dead/dying solenoid in the starter or (hopefully) a poor connection from the battery to the solenoid. Follow the heavy wire (cable) from the battery + terminal to the next junction. Loosen & wiggle that junction, maybe even take it apart & wire brush it. Retighten it without going overboard. While you're at it, wire brush both battery terminals & the cable clamp. You get the idea, follow the trail to the starter and make sure all electrtical connections are good. Ground connections are also important to complete the circuit back to the battery, but IMHO are less likely to be a problem. It won't hurt to check. After all that, it might be the battery.

When cranking the voltmeter dipped to about 4 volts. Sounds like this points the finger at the battery.

not to
 

be mr obvious again but did you check the cables for cleanness and the ground wires? then i would have it tested separately in case your charger is suspect.

tom w

The cables and everything are in really good shape. I just had a friend have to replace a good chunk of his electrical system because of bad cables/terminals so that was the first things I checked. :)

Something similar happened in my brothers 98 Blazer. Unpleasent clicking noises when trying to start (about 2 a second), he thought it was the battery, so he replaced it and the problem went away. A couple days later, problem returned. Turns out the alternator was busted and all replacing the battery did was allow the car to drain it until it was dead. Don't know if this helps you, but I'd thought I'd put it out there.

John