DIY: remove repair replace belt alternator and voltage regulator finish up

here is the rest of the story...

 

Great DIY JOB!!! :thumbsup:

Thanks... I 'm going to do mine this Summer.

What was the mileage on your alternator?

 

voltage regulator mileage before failure

My regulator had 90K on it - the brushes still had plenty of life left, though.

 

Thank for the good work.

Is this a Bosch or Valeo alternator?

 

Great write-up!

 

Great job. Thank for taking the time to post.

 

My alternator has 120,000 miles on it and works perfectly, but I want to change the VR brushes before the embedded wire starts to score the rotator slip rings, which is somewhere around 140,000 miles...

What is the Part Number on your Bosch

VR? My alternator is a Bosch, but I cannot see the VR on the backside. Autohausaz has a Bosch VR for $27.00 with the part number: 1197311242

I sure hate to take it all apart and find out it is the wrong part!

 

That would be the wrong one, (we have the same car). SF Benz sold me mine for just over $50 with tax.


garzonetto, this is a great write-up, but if I may add a couple of notes for others.

First, if you plan on DIY tasks for your car, buy a decent set of external torx sockets. You can get the Lisle set at Sears for under $20, better than using the wrong tools for the job. (Sears sometimes puts their Craftsman sets on sale and they are about $20 when they do so, $40 otherwise.) The bolts that secure the alternator are actually external torx, E13 if memory serves, which is a common size fastener under the 210 hood. (IIRC the same one fits the bolts to remove the AC Compressor to move it if you're doing the motor mounts.)

Second, if you have the newer tensioner design you don't touch the center bolt, rather there is a bolt head (17? 19?) that is used to release the tension. To my knowledge there is no reason to remove the pulley, all you need to do is release the tension and then slip the belt off (often it slides more easily off the idler pulley).

Third, a visual inspection is great on the alternator, but the actual diagnosis requires that you confirm the rectifier bridge is working properly (no dead diodes) and that there is continuity through the windings and no shorts to ground. Just having a light on the dash tells you only that there isn't sufficient system voltage, and while most often it's the regulator on the late model MB, it's best to confirm there isn't a problem with the alternator itself. It would suck to have to buy the regulator twice, once from the dealer and the one that would come with the replacement alternator.

Take care and enjoy the ride,
Greg

 

Great illustrations!

 

This is one of the issues I have with autohausaz. They do list the Bosch 1197311242 as the (only) VR for up to 2001 E-classes.

I bought one last year to keep it in the trunk but now I found out I have Valeo alternators in both of my cars.

So if someone needs a (new) Bosch 1197311242 VR, let me know and I can sell it for cheap.

The Valeo VR is more expensive and harder to find but dealers have it.

 

part numbers

I used part number BR14-?? F00M 145 340 to replace BR14 - MO F00M 145 247. (They look identical.) The part number on the box from dealer reads: A 003 154 51 06 0064.

My alternator is the 120amp model not the 115amp.

I never removed my tensioner pulley. It is older style but not a recall numbered pulley. I was unsure of the online regulators as well, so I called the dealer. He asked for my VIN. He said that there are a few different regulators, thus the VIN. The gentleman was very helpful. The call lasted less than 5 minutes and the part arrived at my door the very next day. The part number confirmation and fast shipping is why I like using my dealer on smaller, hard to find, and lesser priced parts. It is worth the extra coin to me.

Yes - external torx soket would be ideal - I agree. And true, it still could have been the alternator. Given the w210 track record I was confident my Aces full would not be beaten by four of a kind - but it does happen.

 

I never removed my tensioner pulley.

Weird, your third picture says "pull pulley to release tension and remove belt", that's why I clarified that.

I agree about the alternators and the card reference. I just threw that out there for others, it's always best to check to be sure you're not replacing the wrong part.

Take care and enjoy the ride,
Greg

 

I'm trying to remove the alternator on my 2002 E430 and I'm having a lot of trouble getting it out of the car. I have everything disconnected and I can spin the thing around, but I can not get it out of the car.

It is stuck on either (A) the plastic hose clip or (B) the cooling fan It seems like removing the cooling fan would help, but I'm not sure.

Any guidance is appreciated

 

remove the fan (fan clutch tool neede) and fan shroud. it;s the only way.I had the same problem

 

Thanks

I've just used this article to replace the Voltage Regulator in my 2001 E320.

I had the alternator rebuilt at a local shop, purchased a replacement regulator at the MB dealership, and used this guide to perform the work in my garage.

Everything went well and the computer no longer displays any malfunctions.

Only one note: my V-belt has a tension release bolt under the pulley, so I didn't remove the pulley.

Also, I had some trouble mounting the rebuilt alternator. I used a long screw with a nut attached to suppress the bushings in the mounts. Basically, I had a helper hold the bolt in place while I rotated the nut which pushed the bushing back into the bolt hole. Obviously, the bolt was placed through the mounting hole and the nut was screwed toward the bushing.

Thanks for posting this. It was a huge help.

 

For the 1998 (probably the whole series for that matter) E300D, I did the following before my tummy rumbled and added a night before I got back to it in the morning:

1) Depress the levers on both sides of the rear seat and pull up the rear bottom seat cushion, remove from car.

2) Remove battery terminals from battery. Lay terminals to the side.

3) Lift car, use your favorite trolly jack and jack stands or ramps to get some access under car.

4) Remove the 4 metal self-tapping screws (8mm) from the noise encapsulation panel that covers the oil pan (e.g. not the "front" panel/skid plate below the bumper and extending under the coolant hoses to the radiator and the accessory serpentine belt), set panel aside.

5) get on the passenger side facing upward under the turbocharger and you'll be staring at the underside of the alternator. If the only thing on the fritz per diagnosis is the voltage regulator, you can pop the back off the alternator and get the regulator unscrewed. Remove the battery terminals. The nut is supposed to stay on the negative wire terminal but may fall free on the positive. The terminals have tabs to keep the nuts from turning that you'll need to bend away and then bend back over when you are reversing this task.

6) Remove the 3 screws holding the back of the alternator on. In my case, the washer under the positive terminal wouldn't come out over the stud without a lot of prying with my mini screwdriver set. Take care not to damage the threads if this happens to you.

7) Pull the three lock tabs on the perimeter of the back of the case.

8) Jam a screwdriver under the black plastic cap on the back of the case and start prying gently around it until it pops free.

9) After back is popped off, locate voltage regulator and unscrew the 2 setscrews holding it in place. Pry out the voltage regulator if it sticks.

10) Replace regulator with new unit, screw in with set screws, reattach back and fit the screws holding the back on and the wires and nuts re-attached.

11) Re-attach battery and start car (before you put cushion back, always test). If the car starts, check for warnings on display. Follow procedure for clearing the errors per shop manual.

12) Refit noise encapsulation panels and tighten.

After ignoring the noise of the front bearing and getting tired of battery drain with my WVO electrically heated fuel system and the stock 90 amp alternator, I ended up replacing the alternator with a 150 amp unit and have not had problems since. I was able to recoup about 30% of my costs for the 150 amp upgrade by selling the alternator with it's relatively "new" voltage regulator. It bought me some time while I found a decent upgrade that didn't cost more than $200.00 (mission accomplished at $175.00 for a genuine Bosch unit with correct free-wheeling pulley, bracket and clock position, same wiring terminals).

Always thread a new belt if it is glazed or cracked. The one downside of serpentine belts is the neglected ones when they slip (more likely than breaking) everything is affected, whereas V belts tend to cause only one or two accessories to fail. I'm still getting used to serpentine, call me old fashioned. I replace mine about every other year when I drain the coolant, replace the thermostat and seal, bleed the brake fluid and re-pack the wheel bearings.

Drop the tensioner spring via a lever in the black plastic tensioner bracket (the tool is in the tool roll, a small aluminum lever with a knurled end, it's amazing how well it works one handed) and removing the bolt that holds the tensioner in the extended position. When the spring is relaxed, unhook from the bottom of the tensioner assembly.

There is a bit of a trick to threading a new belt around the idler pulley, it took me about two hours to figure out on my first Mercedes diesel, but fortunately all my MBZ diesels since have used the same basic arrangement. Thread the belt with the grooves facing out, diagonally from the steering pump down between the central idler pulley (part of the tensioner system) and the crank pulley. Pull the loop down and first around the alternator and then around the fan assembly. Take up the slack a bit more and wrap the top of the loop over the steering pump, AC compressor, water pump and finally the alternator.

With the panels off, you can make sure you don't have a twist in the belt. When you have it completely threaded, pull the belts in the direction of rotation, it should move with limited friction and smoothly (remember that the crank pulley isn't moving, it's slipping over it, all other pulleys will be turning freely allowing this test to work). If you have an undetected twist after this operation, this test will find it.

Good luck.

 

Could someone please look at pictures of my voltage regulator?

http://www.benzworld.org/forums/w201-190-class/1457738-replacing-aletrnators-voltage-regulator-2.html#post4164781

I'm trying to find out why I've got a schizophrenic instrument panel and an engine on 7 cylinders. The panel goes crazy more so when the gas pedal is pressed hard and suddenly.

Any advice would be appreciated.

 

As a general rule it is EXCEEDINGLY HELPFUL if you post the specs for the car you're talking about. You're posting into the W210 forum with a link to a post in the 201 forum about a different issue -- and the car in your profile is a 129. If it's a 201, there aren't a whole lot of parallels between that and the W210. If it's the SL that is in your profile and you cross posted that to the 201 forum and linked it back here...well...hopefully you can get the confusion?

I haven't spent much time in the 201 forum but I know there are some pretty sharp people poking around in there, so it would be like getting hit by lightning (or pure dumb luck) if someone here stumbles on your hijack and identifies your issue before the 201 folks.

Good luck.

 

I'm in the process of replacing the alternator on my 98 e320. I bought the tools to remove the fan from the waterpump. Do I turn the fan nut to the right? It's not looseing at all.

 

To loosen turn in direction of normal rotation. It is right hand thread.

 

Do I turn the fan bolt to the left to loosen a right hand thread??

 

Looking from front of the engine fan/water pump turns CCW. To loosen turn in direction of rotation (CCW).

If you grasp that concept you will not have problem working on Ford or BMW. On those fan/water pump turn clockwise. Fan clutch nut has left hand thread. Again to loosen turn in direction of rotation.

 

Alternator and Voltage regulator question

I have a parts car for my 97 e420 w/120,000 miles and was considering using the alternator/voltage regulator from it to put on my driver e420 which just showed battery charge error and I checked v belt on side of road to make sure it didn't break, and it was fine. Later the car just died on side of road and I put new battery in this am and started car and voltage was about 11.7 at battery, which as I now understand doesn't mean much when the car is running, I will go back and check alternator voltage via climate control and I expect it will be low. Can you tell me if there is a way I can check the alternator, voltage regulator from my parts car after I remove it to make sure it is good before I take the time to install it and then then find that this alternator/voltage regulator is no better. Would autozone/parts store be able to tell me if it's good or bad?

 

I have a parts car for my 97 e420 w/120,000 miles and was considering using the alternator/voltage regulator from it to put on my driver e420 which just showed battery charge error and I checked v belt on side of road to make sure it didn't break, and it was fine. Later the car just died on side of road and I put new battery in this am and started car and voltage was about 11.7 at battery, which as I now understand doesn't mean much when the car is running, I will go back and check alternator voltage via climate control and I expect it will be low. Can you tell me if there is a way I can check the alternator, voltage regulator from my parts car after I remove it to make sure it is good before I take the time to install it and then then find that this alternator/voltage regulator is no better. Would autozone/parts store be able to tell me if it's good or bad?

TJ,

It sounds to me like a problem I had not long ago with my E300D. I pulled the alternator, had it tested in two locations (the first had a test machine that failed to apply a 20 amp or greater load) and determined from this the alternator and voltage regulator were fine. Most autostores have testers, just make sure they spin it in the right direction since a lot of these alternators use a ratcheting pulley (rotation should be clockwise). The test, if conducted properly, should determine if there is a problem at the rectifier bridge, voltage regulator (usually the brushes) or bearings (it will be noisy).

If the alt comes back clear, the remaining items to test, in order of liklihood, are the ignition switch/control box (EIS I think is the name for system on post 96 cars, regular blade keys use the older ignition switch type) and bad grounding from alternator to block, block to chassis and battery to chassis. Finding bad grounds is tough, usually you just piggyback a new cable which saves some time. I have a British car that has grounds to every major body panel.

The ignition switch carries all of the loads of the car with very few exceptions. Over time, connections in the switch erode from these loads. I've had to replace the tumbler on all of my older Mercedes (bladed, pre electronic keys) and the ignition switch electrical connection behind that tumbler on two of them (the same two that have bigger alternators and higher loads).

Good luck, you can do it.

-BH

 

First thank you for this quide. I am replacing my alternator at S320 W220. The setup is the same, but after removing the alternator bolts it is stuck in place....I can not move alternator. I appreciate any ideas how to release it.



I apply some WD40 and give it another try...

 

Apply some leverage - it will come out. It's always a tight fit, by design. Since the belt is off, all you have left is the relative tightness of the bracket to the alternator. There is a kind of "slot" on top of the alternator. You can get a large screw driver or crowbar in there to lever it away from the bracket.

Once out you can take a breather. You'll use that same lever to get it aligned going back IN which will be less tedius with a dolop of grease (not solvent oil like WD40) to aid.

-bh

 

ON my 1996 E320 I have to turn the tension pulley clockwise to release tension; in your DIY it is counter-clockwise. Has it changed with post-lifting MY's?

 

Be gentle

Use a pry bar

 

thank you again, I was successfull....brushes are ok, so tomorrow I give alternator for rebuild

 

At 221,000 miles I decided to check brushes on my alternator. My hopes that one of two PO would replaced them didn't check out and my brushes are gone, although still work. I was thinking about finding just brushes and solder them into old holder, but than run on ebay into aftermarket regulator for about $23 delivered. They also have Bosch regulator for about $40, but picture shows it "Made in India".
So I am going for the cheaper one, since I will have old regulator as a back up.
My Bosch alternator has regulator part number 1197311242

 

The regulator that the dealer sells is also made in India.
I went over there to price it while troubleshooting my "Battery Charge" problem, and they had it for $149.00 taxes included. ( this is a Miami Dealer.)
As my alternator checked out with burned diodes and a bad bearing, I bought a reman Bosh on Ebay (seller with 99.9 reputation) and I have it already installed in my 420.