Jumping the Starter - Page 2 - PeachParts Mercedes-Benz Forum

Gregory · #16 07-19-2015, 09:27 AM

I drove home to Idaho from San Diego yesterday, Saturday. I stopped somewhere turned it off and then jumped it, but this time I held the jump long enough for it to start, with the key on.

The next time I turned it off, about 45 miles south of Las Vegas, the starter would not turn when jumped. Some heavy sparks at the jump points was it. Holding the jump long enough to start the engine apparently totally fried the solenoid, so don't do that.

I found a guy who agreed to pull-start the car with his Jeep and a rope. At 25 mph, it started right up. I left it running for the remaining 9 hour drive home, refueling it while running.

Before I stopped the engine at home, I ran the car up on portable ramps to give clearance under the engine bay, to remove the starter today.

Gregory · #17 07-19-2015, 08:28 PM

I got the starter out from under the car. I got stuck until I found a thread here. It's a bear to crank the steering to the left, engine off, with the front tires up on ramps. After the third try I finally got them turned enough to slip the starter past the steering gear.

The 25 inch extension on the socket/ratchet wrench to remove the two 10mm allen bolts holding the starter was also required info.

Anyway, the starter is headed to the rebuild shop Monday morning to fix the solenoid and whatever else.

tyl604 · #18 07-20-2015, 01:57 PM

Yuke - I think it is the solenoid that you tap with a hammer instead of the starter.

Still confused about why I used to rock the car in gear to get it to start... at least that is what I remember.

Maxbumpo · #19 07-20-2015, 02:52 PM

Quote:

Originally Posted by Gregory

If the solenoid is sticky using the key, why does jumping it make it engage?

Because you are bypassing the ignition switch and probably a connector or three, maybe the neutral safety switch. All of those things and connections will use a little bit of power and reduce the final voltage at the solenoid. When you jump the starter with your method, you are getting more voltage and probably more current (both provide more power) to the solenoid, and that is enough of a boost to make it work. Then when you use the key immediately after, the mechanical bits of the solenoid are still a little warm and ready from your jump, so it will work.

I "drowned" a solenoid when a street flooded, 1995 E300 sedan, water was up to the door sills and just getting the floorboards wet. Starter / solenoid was submerged or nearly so. Car started immediately but I had to drive down the flooded street (to escape from the rising water) and the forward movement pushed the water level up in the engine compartment and certainly submerged the solenoid at that point. The solenoid became balky, I finally replaced it, no issues since then with the starter or the solenoid. In my testing I found that the key-supplied voltage to the solenoid was about 10 volts, jumping the battery directly to the solenoid provided 12+ volts, but with time the corrosion in the solenoid made jumping it less and less reliable and they cannot easily be opened up to be cleaned.

If PeachParts does not sell the solenoid, try here:

- Alternator & Starter Parts Wholesale

Gregory · #20 07-25-2015, 08:47 AM

The local auto electrics shop rebuilt the starter for $150. They put on a new solenoid, a new drive gear, a bushing, and a CE Frame, which is the starter end cap with the brushes. Labor was $36.

It goes in today.

Gregory · #21 07-25-2015, 04:21 PM

I installed the starter today. The only glitch was the bracket on the back of it.

I tightened the two main bolts for the starter before mounting the bracket. The new, and apparently different back of the starter would only align with one of the two bolts. Also the hole in the bracket did not align over the cup for the axle.

So the bracket only has one bolt in the starter, instead of two.