Hey all- Im under the e300 to check grounds, pull alternator for testing. Could anyone please tell me where to look for ground straps? I'm just not seeing them anywhere! Thanks -J

Um... Is it true that MB couldn't just run a cable to ground on the chassis like everybody else- but wrap the thing in a sheet of aluminum (?) and run it forward a couple of feet to terminate it on the front fascia?

Just wanted to post so that others will know that you have to pull the rear belly pan to find the ground strap...



The aluminum covered cabling is the ground to the block for what appears to be headlights, etc. I hope this saves somebody some time and trouble. -J

also look by the transmission bell housing on the drivers side. On the '98 I got my 606 from there is one there as well in a rather fancy grounding set up

Here is a picture of the ground strap in my '96 E300D (W210, OM606NA), taken while I was replacing the starter motor. The ground strap runs from the engine–transmission junction to the frame of the car on the left side.

Jeremy

__________________

"Buster" in the '95

Our all-Diesel family
1996 E300D (W210) . .338,000 miles Wife's car
2005 E320 CDI . . 113,000 miles My car
Santa Rosa population 176,762 (2022)
Total. . . . . . . . . . . . 627,762
"Oh lord won't you buy me a Mercedes Benz."
-- Janis Joplin, October 1, 1970

Thanks to you both! I will try and upload a picture of mine- it's NASTY. I hooked up the multimeter to see if I could get a load reading- and get this- it's out of range! The bolt is also not breaking loose at the bell housing- and (after an hour of looking) I can't find my breaker bar- so it's off to go buy another one, oh and a ground cable.

Oh and tonight, I'm sure I will dream about hydraulic lifts.

Here it is! The Jolly Green Ground Strap! (the far side of it anyway)

After pulling the second belly pan- (which is a neat rick when you're only got the car up on 2 jack stands in the front), you can access the ground strap easily seen in Jeremy's post. (Thanks Jeremy!) It was VERY difficult to get this thing off- the bolt to the block was practically seized on there with crud, and it was nearly impossible to get a good "bite" on it with hand tools. The long open end box wrench wouldn't fit well, because there is a projection from the block that prevents it from fitting on the head of the bolt properly. Short open end (lighter duty) open end box wrenches fit, but then I didn't have enough leverage to loosen the bolt, and I was afraid to use a "persuader" for fear of breaking the wrench like has happened before) on another project. My nice 1/2" breaker bar has a lip that also bangs up against this fin/projection thing so the socket wouldn't get on there either. And the socket wrench that fit- (again lighter duty) fit fine and could even move through a 45 degree angle to loosen the bolt- but was too short to give leverage again. Oh, and you can forget about getting your impact wrench up in there- no room! So I finally just got the big open end box wrench on it- at an angle where I had the most contact with the bolt between the jaws- and gave it a good jerk- and heard a "Crack!" Fortunately, this time, I had not sheared one of the sides of the wrench off- but actually loosened the nasty bolt- and was able to get it out with the short ratchet.

Kinda looks like a neon stalk of Asparagus.

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Here's what I did: Ground Straps aren't stocked at my local stealer, ("I can order you one from Germany, blah, blah, OEM is a little expensive but blah blah") and a search on pelican parts turned up nothing. So, I went to a couple local parts stores- and they only had nasty thin aluminum straps- and were surprisingly pricey. I asked about copper- and was told it was "too expensive" so the aftermarket companies are making them out of copper coated aluminum, or aluminum. They could special order me one in copper- but it would be over $35 plus tax, shipping, and etc. I moved on.

I picked up a 2 guage copper core battery cable at a discount store for $4. One end had a terminal that was the right size, but the other end had one of those "screw-in" battery terminals. I cut it to length using a hacksaw, (was happy to see good quality small stranded wire in the cable) and went and picked up a set of ring terminals (to fit 4 to 2ga cables) at a discount parts store for $5. I then cut the insuation back on the cable and old-school crimped the ring terminal on. Then I used my propane torch and soldered the ring terminal onto the cable, put corrosion inhibitor on it, wrapped it with tape- and installed it.

Reading it here, it sounds very simple- but it was a waste of nearly a day tracking this stuff down and building this thing. Hopefully it will provide many years of happy er.. grounding.

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Help I have a 300sl 1992 and need to replace the drive belt. I have looked every where i know to find what wrench to release the pressure on the belt and cannot find a post on that . Can anyone help?

Halsteg,
I plan to do another post on this later- but my tensioner on the 96 e300 looked like the pic I'm attaching (which is similar to my 87 190d too.) Circled in the picture is the pointy end of an old fashioned tire iron which is inserted into the tensioner spring pivot. To the right of that is a nut to be loosened. To slacken the belt on this car, you have to undo the nut on the right with a wrench- while maintaining pressure on the spring loaded tensioner and the belt, by pushing the tire iron to the left. Don't force it- just try and hold it in place where it is- isn't very much force. Then after removing the nut, you push the bolt back toward the engine to get it out of the tensioner pivot, and SLOWLY, CAREFULLY release the tension on the tensioner by allowing the tire iron to move to the right. Let me know if this helps. Pic is below.

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Did you inspect the ground strap that bolts to the frame from the negative terminal on the starter. Located top right of your picture.

In my 85 300D, it comes off a lower tranny bolt, driver's side. I knew it wasn't doing its job when I saw the speedo cable smoking when I cranked the car with the cluster pulled out. Aluminum is not an assured electrical connection, so remove it, sand and coat with silicone di-electric grease. I wouldn't worry about the green on the cable itself. Wouldn't hurt to add another ground wire to the top of the engine from where BATT- bolts to the frame.

Hey guys,
I missed the ground from the starter- so I'll have to roll back under there and clean that one up- I pulled the plastic cap off and it looks pretty clean but I might as well do that one too...

I am pretty sick of cleaning ground connections at this point! I've hit each of these with sand paper (nut and bolt, washers and coneectors)- cleaned to a nice shine, and applied silicone grease/ anti-corrosive:
- The big ground strap described above.
- The ground for the battery located on the forward aspect of the back seat on the passenger side.
- The mass of brown ground wires under the hood, passenger side.
- The mass of brown ground wires under the hood, driver's side.

And- after all that, with a brand new alternator- after running for 10 mins, I'm still only getting 12.1- 12.5 volts on the climate control display and 13.1 at the battery at 3000 rpm. I do have a slight belt squeal that I didn't have before however- so I'm hoping that by replacing the serpentine belt and cleaning any grease off of all the pulleys- any slip will be gone and this project will finally be done... If I'm not getting proper output- it's either the battery, or I'm missing something and at a complete loss. Any other suggestions appreciated! -John

Well, following proper etiquette, I'm here to post the conclusion. I should also point out that this thread is actually related to this thread:

143A alternator from 96 S420 in a 96 E300?

Because cleaning up the ground straps was part of the alternator check/replacement job.

I didn't do anything to the last ground strap (to the right of the big ground strap from the bell housing in the picture posted earlier) because when I put my ratchet on it and "grazed" the anti-roll bar- there was a spark, which startled the beezeejus outta me. I went online and tried to research this strap- but out of time, patience, and money and after the nagging from the other room, I decided to just let it go and finish what I had started.

The cause of the belt slip was greasy pulleys and serpentine belt. The last two oil changes were done with filters I provided, but the filter cartridges I got through "special order" didn't come with the large o-ring for the filter housing cover. As a result, the o-ring that was in there lived through 2.5 oil changes- at which time it, oil began to seep around the cover. I guess the oil was flung around, and ended up mucking up the pulleys and the belt. So- about an hour, a half can of carb cleaner, a roll of paper towels, a 2" wide brush from the dollar general store, an old athletic sock (which actually fit into the pulley grooves nicely), another hour and a new serpentine belt later, no belt squeal. Fortunately, it was (a freakish) 55 degrees here today- so I was able to open the garage doors- so I didn't have to inhale too much carb cleaner fumes and get dain bramage.

The result? When I revved to 2500 rpm and watched the climate control display to see if there was a change in voltage- I was shocked because the dome lights burned brighter than they have ever been since we owned the car, and the voltage jumped up to 13.5V. This has to be due in large part to replacing the rotten green asparagus ground strap, and cleaning up all of the brown wire- ground points under the hood, etc.

So- all done. Thanks for all the helpful posts! If this thread helped anybody out- post here let me know! Cheers- J