Diesel SL - Time for another Road Trip - Page 2 - PeachParts Mercedes-Benz Forum

dude99 · #16 09-04-2014, 01:06 AM

There are certain area's of Vancouver where you see them more often. They are around.

dkr · #17 09-04-2014, 02:07 AM

I saw a bunch in NorCal and around Salem, although I didn't see any W123s in BC. I got a bunch of attention WRT my car in BC like nobody had ever seen one before -- or perhaps one without the Northern rust.

Dkr.

dude99 · #18 09-04-2014, 02:19 AM

Not a lot of w123's driving about, but you see a lot of w126's around

t walgamuth · #19 09-04-2014, 07:01 AM

Quote:

Originally Posted by EDBSO

PCH 1 is way to big and busy. Get off onto the Avenue of the Giants and dodge some redwoods.

Beautiful drive. I have also done PCH Vancouver to San Diego, a must drive for all.

This drive through the redwoods is as close to a religious event as I have found.

dieselbenz1 · #20 09-04-2014, 08:51 AM

For a pleasant relaxed trip back to the states you may wish to consider taking the ferry back at Horshoe Bay drive through the islands to Victoria then take the ferry and I believe you end up in Squamish. The people on the islands seem to hord the 123's and you should spot more than in Vancouver it's self. This would all be on your current route but you'd miss out passing back through Vancouver if that matters.

charmalu · #21 09-04-2014, 12:31 PM

While you are in BC, stop and see Butchart Gardens.

The Butchart Gardens | Over 100 Years in Bloom

Butchart Gardens - Wikipedia, the free encyclopedia

I saw it back in 1956 with my parents while on vacation.

Charlie

PackerEdgerton · #22 09-04-2014, 06:00 PM

We need more photos!

I'm in the Portland, Oregon area (which you just drove through). There are quite a few W123s in this area.

-Packman

Skid Row Joe · #23 09-04-2014, 08:35 PM

Quote:

Originally Posted by mach4

On these road trips I continually find it amazing how absolutely few 70s, 80s MB (107,123, 126 etc) there are. I can't remember seeing a single one on the entire trip until today at Stanley Park, where I spotted a silver SLC, but not in time to snap a picture.

I actually thought there would be a good chance of seeing some on Labor Day, the thinking being that people would bring out the cars on a holiday weekend. But no luck.

Two days from San Diego to Vancouver, BC Canada is a grind. When you don't have time or other means that would permit you to meander, then it's just Interstate deadheading. Your hwy only mpg of 34 point something is terrific for a car that heavy, regardless your mods on it, IMO. What else could you do to improve that? Would you rather have a 98/99 E300 I6 in it? I'd like to get back to the coast for a few months to spend the time doing just that - meandering the coastline. It's such a long drive out there in the first place from Texas, though. Definitely want to do that one Spring to Fall soon!

mach4 · #24 09-04-2014, 11:43 PM

Today was a day to head out from Vancouver to Whistler. The drive is absolutely spectacular as the following couple of pictures show.

Above is a YouTube video from the dash cam - Squamish - YouTube

Here's a couple of shots of the SL along the coast road.

Unfortunately we didn't make it past Squamish...

Going through town, I noticed a Canadian Tire store. Having heard a lot about this store on the forums, I decided it would be a mistake to not make a stop and see what the interest is all about. It is indeed a fascinating store.

Unfortunately when I returned to the car there wasn't enough juice in the battery to start the engine. It was indeed fortuitous that I chose too make the stop at Canadian Tire. They were able to determine that the battery was OK and gave it a full charge. We were unfortunately unable to do an alternator test. So looks like I'll be heading back to San Diego without a charging system. I'm not convinced the alternator is bad and I don't have the tools or diagrams available to troubleshoot/fix on the road.

...so that also means that the trip back on 101 is out of the question at this point.

dude99 · #25 09-04-2014, 11:49 PM

Ahh the sea to sky highway, always a beautiful drive, no matter the time of year. Good thing you didn't buy a crappy tire battery, they are absolute junk (I used to work there). Glad your enjoying your time in BC. IF you haven't already the vandusen gardens in Vancouver are worth seeing. I'm assuming you've already left whistler, but if you haven't the WildPlay Zip lines are well worth doing.

Note: On the off chance you want to try a regulator for the Alt, Lordco (a chain of auto parts stores all over the lower mainland) almost always have one in stock for about $13...

uberwasser · #26 09-05-2014, 12:10 AM

Does sound a lot like a voltage regulator failure.

Thanks for sharing your trip with us. Best of luck!

mach4 · #27 09-05-2014, 12:33 AM

My understanding is that the voltage regulator is internal on these alternators (I'm using the one off the 617.952 donor engine)

The plan is to just swap in the spare alternator when I get home to see if that fixes it.

The weird thing is that the alternator dash light was off (when turning on the key) earlier today, then tonite it was on as it should be and then later was off again. It's at 12.4 volts off and 12.2 after starting. I'm not convinced it's not in the wiring of the car somewhere.

uberwasser · #28 09-05-2014, 12:51 AM

The voltage regulator on (most? all?) the W123 turbo diesels (617.952) is serviceable separately. My friend just did his a few months ago on his 1984 300D (same engine). Had exactly the same symptoms - all OK one day, next day does a long-ish trip and loses charging. Find out after making a few short trips, when coming back to the car to a mostly dead battery.

Drove home without any charging because he didn't have a replacement on hand. Ordered one online, none available locally. Swapped it in his driveway. Done. Good since.

I'd say it's the first and easiest thing I'd at least try, if it's true that there a some available locally. Lacking the proper diagnostic tools, it is at least the easiest and cheapest "throw a part at it" method available.

As a side note, it's now something I carry a spare for in my trunk along side the fuel filters.

uberwasser · #29 09-05-2014, 01:00 AM

By the way, I think you of anyone here will appreciate the depth to which my friend went to understand the charging system as he looked in to why his car acted how it did (not much if any indication of charging system failure from the battery light). It shed a lot of light on a lot of items that get discussed in brief on here without much more description.

Quote:

1. The alternator has two outputs (called D+ and B+) B+ goes to the battery to charge it. That's the "main" output of the alternator, and we are able to measure it when we check voltage at the battery while the car is running. There's also D-, which is just a ground.

D+ shares the same voltage as B+. The only difference is that it is lower amperage. This is the famous "blue wire" and it is used by the voltage regulator. The regulator's only job is to sense the D+ voltage and variably increase resistance to the line called DF (Dynamo Field). This is the key to the whole thing.

DF is an input to the alternator. When the voltage regulator changes the resistance between D+ and DF, it is effectively raising or lowering the current that can go to the alternator's magnetic field. Altering the magnetic field strength causes the alternator to change output. More power to the magnetic field = more voltage from the alternator.

In other words, if the alternator is cranking out a lot of power, D+ is high and so the voltage regulator increases resistance, which lowers current to DF and causes the alternator to lower output. At about 14.5 volts, the voltage regulator will cut off the circuit entirely, which brings DF to zero and stops the alternator from producing any power.

Similarly, low D+ voltage means the voltage regulator will lower resistance between D+ and DF, to increase magnetic field strength. So to sum up, D+ is identical to B+ (battery charge) and is used simply as a feedback loop so the voltage regulator can know what to do.

This means that one possible failure mode of the regulator is for the integrated circuit to incorrectly cut off current to DF because it "thinks" that input voltage from D+ is too high. Note that this will cause the battery to fail to charge but not cause the charge light to illuminate while the engine is running until the battery is entirely dead, for reasons I'll explain below.

2. If the D+ output is at zero (as when the ignition is ON but the engine is not yet running), the voltage regulator lowers the resistance between D+ and DF to nearly a short. This means the alternator gets its DF power from the battery, via a long chain of components: BATT --> ignition switch --> charge light --> D+ --> regulator --> DF. This is why the charge light illuminates—there's a 12v differential between the battery and the D+ circuit. Power is flowing from the battery, through the charge light, to DF.

This is also what they mean when they say the alternator needs "exciting". E.g., the alternator needs a 12v power source to initially magnetize it. It won't produce any power otherwise. Once the alternator is running it produces its own power via the D+ line. (In the Pirate4x4 discussion, the initial 12v power source is referred to as the "field current supply," and it says that this is a separate input to the voltage regulator, but in the Bosch system it isn't.)

3. The charge light illuminates only when there is a voltage differential between the battery and the alternator, OR the alternator's D+ and B+ outputs. As I noted above, the light goes on when the car is turned on but not running, because the battery is supplying 12.6 volts and D+ has zero. Likewise, if the battery is dead or refusing to charge but the alternator is working, D+ will have up to 14.5 volts but the battery will have perhaps 11.6-12.0, and so the charge light might illuminate weakly. (It would be interesting to test if the 2-3 volt differential is enough to illuminate the light enough to notice in normal daytime use.)

Why would D+ or B+ not have the same voltage? Because they have separate diodes (3 each) that rectify the output of alternator (each one converts a "phase" of the alternator's AC output to DC). If a diode fails on either D+ or B+, output voltage drops by 1/3.

Actually, a single D+ diode failure can mean there would be much lower or even zero output at D+. According to the Peach Parts description, the drop in voltage at D+ would cause a cascading effect, since this would cause a commensurate drop at DF and hence a further drop in alternator output ... which of course means a further drop in D+. The overall drop in voltage would illuminate the charge light while the engine was running, which didn't happen on my car. So I can eliminate D+ diode failure from my troubleshooting process.

Similarly, B+ diode failure could mean the battery doesn't get enough voltage to charge. The battery will act as a "buffer" in this case, providing 12.6 volts for a while, but there would be a differential voltage between D+ and the battery. The voltage differential would be larger whenever the engine was revved because alternator output would go up a little with higher revs, even with a bad diode. So the symptom would be a voltage light that comes on weakly when running, and gets brighter as the battery runs down or the engine is revved up.

In my case, I didn't observe a charge light at any time. This doesn't prove all the B+ diodes are OK, since one could have failed and the rest could still be putting out some power, but I would have likely seen a dim charge light when I was driving home, especially toward the end of the drive when the sun was setting. The best test is to check voltage while the car is running, at the D+ terminal ("blue wire") and the B+ terminal (battery positive). They should be identical. (The trick is getting to the D+ terminal with a probe while the engine is running; it's down on the rear of the alternator.)

There's another set of "common" diodes in the alternator that affect both B+ and D+. However, if they failed, I think the alternator would have no output at all. Once again we'd have a large voltage differential between battery and D+, illuminating the charge light.

(By the way, as I'm sure you've read, if the charge light is burned out or incorrect wattage, it breaks the electrical circuit between the battery and D+, and thus the alternator has no magnetic field and will not put out any power. A burned out bulb would be obvious because the light wouldn't illuminate when the ignition switch is on. Mine does. In the case of incorrect bulb wattage, the charging problem would have manifested a year ago. So I can rule out the bulb as a cause as well.)

5. All of the above explains why the charge light is not illuminating on my car, either at idle or high RPMs. Even though the alternator's output voltage is too low to sustain battery charging, it is producing enough voltage to ensure that there's no significant differential between the battery and the D+, at least not enough to brightly illuminate the charge light. Most likely the alternator is putting out identical voltage at B+ and D+ (although I'll verify that shortly).

As we saw, the alternator did increase output to >13 volts when the car was revved. So if the alternator can produce >13 volts, why isn't it doing that all the time? Low output could be the result of mechanical damage to the alternator, but inspection shows that it is in relatively good physical condition (no oil dripping in to it, no rust, good belt connection, electrical connections appear OK). I'm still expecting the problem will be the regulator. My theory is that it's because the voltage regulator is misreading the D+ input OR it is no longer able to variably lower resistance between D+ and DF on the correct curve. I could not find any bench test procedure to verify this, and I don't have a variable DC power supply anyway.

Summary: If the charge light doesn't come on when the ignition is on and the engine is not running, replace the bulb and/or check all the electrical connections at the battery, bulb, ignition switch, and alternator. Note that instrument cluster grounds are not the problem because the battery and alternator serve as the grounds for each other here.

If the charge light stays on when the engine is running, the problem is likely in the alternator or battery. Check the battery first.

If the charge light isn't on when running, but the battery isn't getting enough power, it's either the voltage regulator or (less likely) a failed B+ diode in the alternator. Comparing the output at B+ (battery terminal) and D+ ("blue wire" on alternator) will isolate the issue. Replace whichever component is at fault, since neither are user-repairable.

dude99 · #30 09-05-2014, 02:53 AM

The regulator\brush assembly is accessible on the back of the alternator. Held in by two screws, torx I believe. 5 minute job to change