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  #16  
Old 11-19-2013, 01:31 PM
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0 means GP shorted

If your GP is reading 0 then it is shorted inside and bad.
Use this DIY from Diesel Giant to check your GPs.
It has a lot of good pix.
Mercedes Diesel Glow Plug Repair

Jeff

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  #17  
Old 11-19-2013, 06:18 PM
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Quote:
Originally Posted by Rooster300SD View Post
If your GP is reading 0 then it is shorted inside and bad.
Use this DIY from Diesel Giant to check your GPs.
It has a lot of good pix.
Mercedes Diesel Glow Plug Repair

Jeff
Not necessarily. This depends greatly on the quality and power of the multimeter. I doubt if anyone here has one with that kind of power in the home garage. The meter does a voltage to current comparison to arrive at resistance. An engine block is a significant current sink for any meter to overcome. The plug will need to be removed to measure resistance and even then, the only true test is applying power and verifying it glows, while suspended in free air.

With cold weather rolling in to parts of the country, it might be easiest to replace the glow plugs as a set. Of course, if the carbon wasn't reamed from the glow plug hole and replaced then with Bosch glow plugs, they may have lived a short life.
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  #18  
Old 11-19-2013, 10:20 PM
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Also, make sure your meter isn't set too high on the ohms,
that could also make it read 0. Set it down as low as it will go.

I've never had a GP short out. I've just read that a shorted
GP would read 0. What kind of meter would you need to read that?

Jeff
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  #19  
Old 11-20-2013, 12:16 AM
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Quote:
Originally Posted by SD Blue View Post
Not necessarily. This depends greatly on the quality and power of the multimeter. I doubt if anyone here has one with that kind of power in the home garage. The meter does a voltage to current comparison to arrive at resistance. An engine block is a significant current sink for any meter to overcome. The plug will need to be removed to measure resistance and even then, the only true test is applying power and verifying it glows, while suspended in free air.

With cold weather rolling in to parts of the country, it might be easiest to replace the glow plugs as a set. Of course, if the carbon wasn't reamed from the glow plug hole and replaced then with Bosch glow plugs, they may have lived a short life.
The figures that People most often post when the have good or bad Glow Plugs I think is predominantly with the Cheapie Digital Meters.
I have a better Meter then I normally use but I keep it locked up with the Good Tools and the Cheapie Meter is certainly good enough to tell if you have an open circuit in a Glow Plug.

The other part of that I have not read of anyone having all of their Glow Plugs Fail at one time. That means no matter what Meter you are using you are comparing the readings you get from the Good ones to the possible bad ones.

And, the Ohm Meter does catch a lot of bad GPs.
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  #20  
Old 11-20-2013, 12:35 AM
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Originally Posted by Rooster300SD View Post
Also, make sure your meter isn't set too high on the ohms,
that could also make it read 0. Set it down as low as it will go.

I've never had a GP short out. I've just read that a shorted
GP would read 0. What kind of meter would you need to read that?

Jeff
I argued with someone where I used to work about this.

When something has a short circuit it normally burns something and actually becomes an open circuit.

When you check it with a Meter all you are going to know is you have an open Circuit. You are not going to know if some thing shorted out and burned causing the open circuit or something broke causing the open circuit.

So my end of the argument was is that it is a open Circuit till you find out what caused the open circuit and that may or may not be a Short.

Concerning what you will see on the Ohm Meter an open circuit will show up just as if the Probes are never connected to anything.

If for some reason you had a Short in a Glow Plug that did not create an open circuit inside of the Glow Plug itself the Glow Plug Relay Fuse would burn. If you were to use your Ohm Meter to find that you would find a Glow Plug you would see the Number start somewhere because there is current flow and end up at some low or even zero resistance compared to the good Plugs

On My Cheapie Harbor Freight Meter there if I set it on 200 Ohms on the screen I see a number 1 and three or 4 empty spaces show up and a decimal point to the right and another empty space.
If I put the probes together I get a 00.9 Ohms meaning the My Probes and wires have that much resistance. If I use this Meter in theory I should subtract the 00.9 from my Reading.

On my better Meter when I put the Probes together I get Zeros and I believe some Meters will show the infinity sign.

I the end when you get a Meter read the Instructions. I have not read them for My cheapie Meters.
And, I had not used the Batter Meter for over 20 Years on something that really needed a Better Meter so if something like that came up I would have to do some reading.
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  #21  
Old 11-20-2013, 11:21 AM
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Well, I tired to take a video this morning of the starting issue.

Note: The car started fine all day yesterday morning to evening. I have a 20 mile drive to and from work everyday so there should be plenty of time to charge the battery.

See the link below:

300SD Starting issues - YouTube

Does this sound like a starter? Just seems like I might have a drain on the battery. I need to start checking amps at the fuse box I guess?
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  #22  
Old 11-20-2013, 11:47 AM
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like my other post said....the lights on the dash pretty much clear it up. You either have a bad solenoid on the starter or the starter itself has bad field windings/armature/etc... the wiring seems fine

I was in the same spot two weeks ago. I put a new solenoid in the starter about a year and a half ago. Starter finally let out it's pre packaged smoke. pull the starter. test the solenoid, and then the starter itself....

my post from benzworld.....if that helps at all..
I think I fried my starter - Mercedes-Benz Forum

and since it's not mentioned in that thread. put a set of jumper cables to

1..the positive cable to the lug not connected to anything else on the solenoid
the negative jumper to a clean part of the casing
12v to the smallest lug on the solenoid which is just a signal wire

2..if that doesn't work, remove the big ol strap from the solenoid, and put 12v from a jumper cable to the starter again with it grounded to the casing.

If #2 doesn't work, bad starter
if #1 doesn't work, bad solenoid...

in that order....kinda
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  #23  
Old 11-21-2013, 12:39 PM
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Quote:
Originally Posted by lovinthedeez View Post
like my other post said....the lights on the dash pretty much clear it up. You either have a bad solenoid on the starter or the starter itself has bad field windings/armature/etc... the wiring seems fine

I was in the same spot two weeks ago. I put a new solenoid in the starter about a year and a half ago. Starter finally let out it's pre packaged smoke. pull the starter. test the solenoid, and then the starter itself....

my post from benzworld.....if that helps at all..
I think I fried my starter - Mercedes-Benz Forum

and since it's not mentioned in that thread. put a set of jumper cables to

1..the positive cable to the lug not connected to anything else on the solenoid
the negative jumper to a clean part of the casing
12v to the smallest lug on the solenoid which is just a signal wire

2..if that doesn't work, remove the big ol strap from the solenoid, and put 12v from a jumper cable to the starter again with it grounded to the casing.

If #2 doesn't work, bad starter
if #1 doesn't work, bad solenoid...

in that order....kinda
Thanks, I appreciate the help and I will try this, but first I'm going to check for a battery drain per circuit because I have a feeling my battery is just draining somewhere overnight which makes the dash lights go goofy and the starter sound like it is bad.

Last night, I unhooked the battery cable and when I re-attached it this morning, the car started right up.

By the way, what do you mean by the lights on the dash pretty much clear it up?
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  #24  
Old 11-21-2013, 12:49 PM
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Here ya go if it indeed is the starter and you want to rebuild it.

http://www.peachparts.com/Wikka/OM617StarterRebuild

P.S. Army is now Stretch.
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  #25  
Old 11-30-2013, 04:49 PM
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Okay, just wanted to finalize the thread by explaining what was wrong with the car.

1. Power antenna was draining the battery, so its unplugged now.
2. Battery wouldn't hold a charge any longer, even though Advance Auto parts tester told me it was good. (That is the last time I trust that tester.) I assume this is because the battery was constantly being drained and recharged.

Replaced the battery and left the antenna unplugged and everything is working perfectly. Now I need to get a new power antenna.

Thank you everyone for all of your help and responses.

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