If the starter gets too hot, will it not engage? - Page 4 - PeachParts Mercedes-Benz Forum

1985 300SD Sady · #46 05-30-2006, 04:32 PM

Quote:

Originally Posted by BobK

Andy, for what it is worth.. here in Cincy, with our crazy weather/temps, the problem you desrcibed can be caused by the weather itself. May be another problem, but first look into this: With the wild temerature swings we have had lately (40 degree swing) you can get some funny corrison problems. I usually see these problems in hte spring and fall when the temp change is most pronounced. Battery connectors do not seem to expand and contract at same rate of speed. What you wind up with is a scale on the post and the inside of the cable terminal. This kills ya two ways. First, it is a high resistance to charging. Your battery may not get a full (or even partial) charge. Then, when you try to pull some serious current thru the connection, a la diesel starter, the voltage drop becomnes too large and ya caan't spin the starter. Common symptom is that the car was running but won't start now. Plus the headlights seem to come on fine (they are probably a bit dim, but too little to notice). Solution is to clean the connection really well and reconnect battery. Then put your charger on the battery and bring it all the way up to a full charge. BTW, 12.4 volts @ 70 degrees F. is about a 25% dischared battery. I've got a chart somewhere showing 0 to 100 % charge for a normal battery. I'll have to dig it up. There are other places you can have trouble charging your car. There is a connectin block I'll show you sometime that can completely stop you from charging (guess how I know!).
Clean your connections (if you haven't already), charge the battery (make sure you keep the water level up-distilled water only), and use your voltmeter to get good readings on what's going on. Gotta be able to get to work on time every day (or are you working down the street?)

I will (when it cools off tonight) go out and clean all the connections as well as possible and make sure things are tight.

I will put the charger on also.

Is my battery even able to be topped off with distilled water? I thought these newer batteries were all maintainence free?

Also, if the tester showed that the alternator is charging, why does the battery light go on just when I shut down? (sorry I forgot to mention that)

I will update tonight after cleaning connections.

BobK · #47 05-30-2006, 08:45 PM

Are you saying with the key off, the alt light is on?

1985 300SD Sady · #48 05-30-2006, 08:51 PM

Quote:

Originally Posted by BobK

Are you saying with the key off, the alt light is on?

Only when I shut down the car.

When key is not in, nothing is on. When I turn the key to the glow position all the lights come on and then go off when I start the car.

Only when I just turn the car off (key still in, just not in run position) the red battery light is on. When the key comes out, the light goes out.

What gives?

1985 300SD Sady · #49 05-30-2006, 10:08 PM

weather was too bad to get out and clean the connections.

I will try to do that sometime soon.

My car will still start fine cold, and when up to normal operating temps. I just need to make sure it does not get too hot. It's not too much of a problem right now because if it does not start I can wait or get a jump, its not like it will just quit running in the middle of the road because it does not need electricity to run.

vstech · #50 05-30-2006, 11:30 PM

Quote:

Originally Posted by 1985 300SD Sady

weather was too bad to get out and clean the connections.

I will try to do that sometime soon.

My car will still start fine cold, and when up to normal operating temps. I just need to make sure it does not get too hot. It's not too much of a problem right now because if it does not start I can wait or get a jump, its not like it will just quit running in the middle of the road because it does not need electricity to run.

you could spend 35 - 55.00 at wally world or Sams club and get a Jump battery, they sell them with 450CCA and it would boost your battery problems. just a thought.
John

going_postal · #51 05-31-2006, 01:32 AM

Have you tested the starter to see how many amps it is drawing when ranking the engine,when hot and when the starter is just clicking. THis is a simple test to check the condition of your starter. A voltage drop test on the positive cable,(battery to starter) shold find a problem or eliminate that cable from your list. Just to quess, I woldsay that it is the solenoid. You can check it when it is just clicking, by using a test light. You will need to reach the starter and attach the clip end of the test light to the motor side of the solenoid, then hold the light part out where you can see it, and turn the key, if the starter clicks, and no starter action, and no light, you have no power thru the solenoid, bad solenoid, replace solenoid, or starter, your choice.

Motorhead · #52 05-31-2006, 03:33 AM

You need a "hard start" relay. My 240D did the same thing and the relay fixed it 100%. I didn't need to spend the $$$ on a starter or battery. As the cars get older, the resistance in the wiring, ign switch increases due to wear and loss of good connections. You don't get the maximum CURRENT to the solenoid due to loss. PM me and I will tell you how to hook one up. I have installed atleast 30 of these on various German cars.... 6 and 12 volt VWs and Mercedes

1985 300SD Sady · #53 06-01-2006, 12:51 PM

Chris (motorhead) Has explained to me how the solenoid itself can draw several amps just to close. When the wiring from the ignition switch to the solenoid gets so old it sometimes will not allow that much current (when hot in my case?) causing it to not start. He is going to instruct me on installing a relay to handle this load and use the signal from the ignition switch.

I did clean all my contacts yesterday and went driving and got the car hot again... I shut it off and tryed to restart again while hot (to replicate when it did not start before) and it started fine!

Hopefully I dont see this problem happening again.. but if I do, I will install a relay

Thanks for all the help.