Car dies while going down the road??

Which connectors Jeff? There are a lot of them. On the back of the alternator? Or at one of the terminal blocks, either in the engine compartment or front?

 

Later? I am pretty certain ALL 355's have the battery in the front. (never seen one in the rear)

 

For those that suggested checking the connectors at the battery and alternator, pour yourselves a beer! You earned it!

 

Check the relevant threads, and make sure you get the upgraded regulator if possible.

 

I believe I read some time ago in the 400/412 forum someone who had a similar problem, I remember because the writer made reference to the radio cutting out and other electrical things going spooky.

 

I would first check the connections directly at the battery, then, with the battery disconnected, check the connections at the starter motor, the alternator and the ground straps from the engine to the frame, or any other major ground points. If you had the motor out recently its possible a connection got missed.

The radio signing off just before the car dies is a sure sign of a possible bad connection. Your alternator and battery may be fine, but if the alternator cant charge the battery, or if the battery is disconnected from the car through a bad connection when running, your car may only be running off the alternator at low speeds. So your driving along, all is well, and you come to slow traffic or a stop light. At low speed, voltage drops. Low voltage puts a higher drain on the reserve power as amperage climbs to maintain the same wattage load. Higher amperage taxes your possible weak connection even more, the battery disconnects leaving the car on alternator power only, the radio fades, the fuel pump slows, the car dies.

Your battery cant be good one day and bad another, then good again, unless perhaps its internally shorted. I agree with others to stop throwing bad money after good, and isolate the reason before throwing parts at it. If the charging circuit is marginal, a good battery may fool you that your fixed, and then at some point in the future when it finally gets drained enough, your problem could come back with a vengence. And if you do have a low voltage high amperage problem, its not doing the wiring or switches in your car any good.

 

i would make sure the battery is load tested to be sure it is not been damaged from the ordeal. a meter reading voltage is not the same thing as a load test, especially if the alternator is bad.


best.

 

Your alternator is shot. I had something similar happen, but in reverse. My radio wouldn't come on until a short while after driving the car. I suspected it was the alternator, and then eventually the battery started to discharge overnight once the alternator was fried.

 

Check my earlier post. You HAVE to make sure that the mechanic not only does a battery load test and alternator charging system test but he HAS to run the alternator diode test. An alternator will look like it is charging even if it has a bad diode.

I don't know why so many mechanics skip this test, but it is absolutely necessary to check the diodes everytime the alternator is tested. Otherwise, they are only doing a partial test.

 

The problem is, he said his car will be running along fine, then suddenly the radio dies, then the car. That dont sound like the alternator shutting down, it sounds more like a disconnect or a short. Even if the alternator suddenly died, the car should be able to run for a while on the battery. One guy on here drove a 355 over 30 miles to a shop with a dead alternator. A good short in either the battery or the alternator could do the same thing though if the short exceeds alternator or battery output.

 

From his earlier posts, all of those items were checked.

If there was a short drawing that kind of load, he would have melted wiring.

If the battery had a short like that, he wouldn't be able to recharge it.

Suddenly the radio dying and then the car, only seems sudden because the car was running on battery until it couldn't run anymore. The alternator light didn't come on because the voltage regulator didn't realize there was a problem since it thought it was charging the battery. Again, check the diodes.