Self-Starting 300D! - PeachParts Mercedes-Benz Forum

Sugi · #1 03-22-2007, 11:02 AM

Howdy- Recently on a trip down to Orlando from Athens, GA (about 500 miles) my started bolts backed out during the drive and the starter could not engage the ring gear. Luckily, I broke down near my aunt and uncle's house in Macon and he's a car guy. Starter was retorqued (by the way a GM disk brake caliper tool in stock at most auto parts stores, 3/8 hex socket, will fit the 10mm starter bolts) Everything was cool until the return trip- at 70 mph the starter engaged! What a sound- we were 2 1/2 hours away from Orlando so I decided to not turn off the engine and see if things would "work themselves out" I know, bad but I was trying to get bak in time to play a show. We drove all the way home, engine running even while refueling. Sure enough the starter quit making the noise... When we got home I pulled it and it was grinded down. However, my gamble paid off and the ring gear was not damaged! I went down to AutoDrone and they actually had a rebuilt Bosch starter for $79.00 and it was in stock (wow). I installed it (on a non-turbo '81 with the ACCIII system you can actually just squeeze that starter though from the TOP) The battery was dead (it sat for a few days but may have something to do with the mystery). I recharged the battery but when I went to reattach the positive terminal the STARTER STARTED RUNNING on its OWN. The car did not start. I immediately pulled the cable. I reattached it and the second time it did nothing. I got in the car and it started normally. I tried it three more times and it seemed fine. The next morning I went to start the car and the starter kept on running. I jumped out and disconnected the cable once again. I waited a second and then reconnected it. It worked fine! My question is- could this be an ignition switch problem? As far as I know there's only 2 wires to the starter- the main battery power and the thin wire from the ignition switch that controls the solenoid. Any other ideas? Sorry for the novel but I figured I'd provide as much info as possible!

rrgrassi · #2 03-22-2007, 11:06 AM

Did you replace the solenoid as well with the starter? I have not had to buy one, yet, and I have seen some places sell starter and solenoid separately.

Also, you could be having an ingition switch going bad.

Sugi · #3 03-22-2007, 11:19 AM

Oh yes, the come bolted up together.

kerry · #4 03-22-2007, 11:26 AM

I'd say it's a problem in the ignition switch or the wires between the switch and the starter.

MattBelliveau · #5 03-22-2007, 03:08 PM

Figure out someway to take it back to them. I bought a starter from them for an RX-7 I had, and it did the same thing. I swapped it with a different one, and no problem. While you are down there, check the low voltage wire (ignition) and make sure there isn't constant power there. That would give you the symptoms you speak of. You should only have power there when the key is turned to the start position.

OMEGAMAN · #6 03-22-2007, 03:29 PM

Does this car have an alarm? I would look there if it does and disconnect all aftermarket wires.

redbaronph123 · #7 03-22-2007, 08:04 PM

started happening to my wagon last january. Turned out to be a bad solenoid. replaced it and the started is no longer "sticking" or running amuck when connected to the battery or when you start it.

mespe · #8 03-22-2007, 11:39 PM

A sticking starter is not fun,,, happened to me on my F250. Try disconnecting 2 batteries in a hurry!

redbaronph123 · #9 03-23-2007, 04:48 AM

Quote:

Originally Posted by mespe

A sticking starter is not fun,,, happened to me on my F250. Try disconnecting 2 batteries in a hurry!

hehehe. that's what happened to me.. imagine this.. in the company parking lot, started the car, didnt start, but the solenoid kept on going.. OMG!!!.. run to the back to get my tools, foudn the trunk to be locked, went to the front again, got the key out, went to the back and opened the trunk, got my tools, went to the front, forgot that i never popped the hood, went back inside, and popped the hood, and then wrench out the terminals!... *whew*

All this while i was still wearing my corporate attire, and some of the people outside having their break looking at me.. .

Sugi · #10 03-23-2007, 10:44 AM

No alarm system and thankfully I had a pair of channel locks handy! After that initial episode, nothing else has happened. I did order an ignition switch just in case. Thi is my wife's car so I really have to make sure it won't happen again. Of course I will have to see if I can teach her the "battery cable shuffle/hustle" just in case!!! It maybe easier to just give her a big pair of wire snips...

rrgrassi · #11 03-23-2007, 10:58 AM

Or, a heavy duty battery disconnect switch.

vstech · #12 03-23-2007, 11:17 AM

Quote:

Originally Posted by rrgrassi

Or, a heavy duty battery disconnect switch.

you certainly want a HEAVY DUTY battery switch. do not get that Knife edge one from the parts store!
my 6.2 was having similar problems, so I installed one... totally melted it.
good luck.
John

Sugi · #13 06-10-2009, 10:31 PM

This car has been off the road a while with a blown head gasket. I was driving it today and took a hard and fast left turn. The starter engaged and it made a horrible sound! I knew what it was immediately so I pulled over and popped the hood- I had already installed a quick-release battery cable clamp so it was not too hard to undo it. Like an idiot I had no tools on me (I was only going a mile or so- Murphy's Law). While peering around the starter, I noticed that the battery cable looked a little weird. Turns out that the insulation had melted off the cable AND the smaller power wires that also connect the the starter terminal! There was just enough distance between the wires somehow so they didn't touch. The hard turn moved them just enough to make contacts and engage the solenoid! I spread everything apart as best I could and used a bumper sticker I peeled off to make a little insulation (how's that for McGuyver!). It was enough to get me home. I pulled everything apart and used really good electrical tape to patch it up (it was only about 1/2" of burn through). Works fine now- mystery solved.

DANSMB · #14 06-11-2009, 12:44 AM

Car I bought for parts had a repair invioce for the same problem, it was the nuteral saftey switch wiring shorted near the tranny.

Dan