cranking stopped, quick helps pls!? - Page 2 - PeachParts Mercedes-Benz Forum

funola · #16 07-27-2013, 05:33 PM

Quote:

Originally Posted by pmckechnie

The solenoid has 2 circuits in it to engage it. One PULL-IN and one HOLD. When the switch sends power to the solenoid, both the circuits get the power. The ground for the PULL-IN is through the brushes and armature. A contact inside the starter then puts full battery power to the armature which disables the PULL-IN part of the solenoid and now the HOLD portion holds the solenoid in until the key is released. The HOLD circuit is not strong enough pull the solenoid in and the pull-in draws too much amperage that the starter motor needs to turn the engine over. If the circuit through the brushes and armature is open (brushes worn out) the solenoid will not pull in. The dash lights dim a little because of the HOLD solenoid circuit. You can hit the solenoid if you like, but hit it in the wrong place and you WILL be replacing it. Hit the starter case anywhere and no damage will be done if you use something smaller than a 10 lb sledge.
Believe me, working on NO-START problems in a small shop ( me and 1 or 2 others) for 20+years I did learn a little bit.

Paul

I agree with most of your post. When the solenoid is stuck in the middle due to corrosion, neither the pull in coil or the hold coil is going to do anything. It is stuck and will not click. I've have disassembled solenoids and sanded the corrosion off with 600 grit wet dry and WD40 and fixed stuck solenoids.

As long as you don't hit the electrical terminals of the solenoid, you will be ok. The body of the solenoid is pretty stout aluminum. I've rapped on it hard many times with a 1/2 breaker bar w/o issues. Hitting the body of the starter won't hurt either. So hit both, can't hurt, whichever works. I'd have a jumper to the starter solenoid handy (don't know if the 87's have the terminal block) so you wack it some and pulse the solenoid till it free itself and pull in and hopefully start. Off course you need a good battery also.

pmckechnie · #17 07-28-2013, 08:22 AM

Scott, Do as funola says. The difference in what I say and what he/she says is location. Here in NC I have never seen a corroded solenoid. We don't have that kind of problem in this part of the country unless you are on the coast. You being in Canada and funola being in CT, he is correct in your case.

Paul

t walgamuth · #18 07-28-2013, 09:38 AM

Also be sure to check all your electrical connections. A slightly loose or dirty connection or ground will cause trouble too.

To prime a dry diesel you can spray WD 40 into the intake directly to get it started. Just remove the air filter and spray directly into the intake. It will run on it until the fuel starts pumping. (Don't use ether though).

funola · #19 07-28-2013, 11:02 AM

Quote:

Originally Posted by pmckechnie

.........Here in NC I have never seen a corroded solenoid. We don't have that kind of problem in this part of the country unless you are on the coast.

Lucky you!

Yeah it got old after a while- pop hood -rap and jump solenoid to start. After cleaning and lube solenoid no more problems.

scottmcphee · #20 07-30-2013, 09:28 AM

Update

I cooked things pretty good over cranking.

Solenoid was not functional - no pull in.

And 2 of the four brushes had overheated and unwelded their copper braid connections at their terminals.

Try until you die, those starters give it all until the moment they can no longer.

Damn I have a good battery that allows so much cranking, it's a MB brand battery been in there for the 5 years I've had the car.

Assembled one good starter from all the parts of others I had kicking around. Eventually re-wet everything and bled out air, etc.. Got it going.

But lesson learned: no more than two or three long (15-20 sec) cranking sessions per half hour, to allow that starter to cool down.