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I'm not trying to pull a Tippi with this question, so bear with me.
My idjit lights were always flickering dim so knowing my old harness was toasted I replaced it. This did not fix the light problem (they even got a little more steady!!) so upon the advise of this sage board I just finished putting a new brush/regulator assembly in the alternator. Problem solved, WHY!!??
I never had a charging problem with the old assembly and the voltage output looks the same on the gauge with the new assembly and it looked like the old brushes still had plenty of meat left. Has anybody ever puzzled out why the brush/regulator assembly will cause these lights to flicker even when all other indications lead one to believe the alternator is working correctly?
It really doesn't matter, just have always liked to know WHY something shows a particular symptom (wife calls it a serious psychological flaw) instead of just knowing what to do to fix it! ;-)
Thanks for all of the good insight from this group,
Justin B.
83 244 Turbo - Soon to have new rear bushings then wife.com will not have anything left to complain about!!!
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Who are you kidding. Your wife.gov or wife.mil will find something about which to complain. ;>)
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Warren Bain - '99 V70GLT G-Valve > 70K mi, '96 965 >110Kmi Wifemobile near Manassas Va.. Check the 700/900 FAQ via the 'features' pull down menu.
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I realize it's a dangerous thing to eliminate all sources of irritation as I've always believed that the female genetic makeup does not allow this "state" to be accepted. I am, however, trying in this case just to validate the hypothesis! ;-)
Cheers,
Justin
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The difference between memorizing cause-effect lists and understanding them is what separates a parts changer from a technician. But I agree with your wife anyway, as I also have that same flaw- kills cats, but not us.
Guess:
When the intermittent in your brushes caused the idiot lights to flicker your charging current was undoubtedly varying as well, but the lights could respond much faster to the voltage on the D-61 wire than could the voltmeter, whose movement is damped, could respond to the smaller changes on the main alternator output lead, smoothed by the storage action of the battery. The D-61 wire is the small red wire from the alternator whose voltage is developed from three smaller diodes, separate from the battery circuit, connected to the stator windings.
If your intermittent was much slower, say your idiot lights came on solid for a second or better and went out, you might have seen the voltmeter respond.
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Art Benstein near Baltimore
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For the most part they were more "on" than "off" Pretty steady as of late but dim. When the ignition was turned to the run position they all lit up brightly like they should and once started they were dimly illuminated.
Justin
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First, put your old regulator back in. Verify the problem is repeatable and not associated with dirty connections like these:
Order a brush replacement kit, compare your old brushes to the ones in the kit when you replace them. Try it, let the brushes seat for a hundred miles or so, then keep it or your new one as a spare.
By the way, as Mr. Foster knows, these will seriously strand you, when the weather is worst and at night. When else are you using lights, wipers, defroster, blower fan, ...
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Art Benstein near Baltimore
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Art, that's not a bad idea, I think I WILL scrounge some new brushes and keep the old regulator as a spare. And your top picture looks very much like the contact inside my alternator, which I did clean before installing the new assy.
I don't dispute that there was most likely some gremiln lurking about, waiting for Murphy to kick it in the a$$ when least convenient. I was just trying to figure out why a problem in this assembly would cause ALL idiot lights to glow instead of just the charge indicator.
I remember on a 1969 MGB-GT I had a few years ago that I drove for months with the charge indicator faintly glowing (just the charge indicator) and all of a sudden the light quit glowing. Being the eternal optimist that I USED TO BE I was grateful that it had fixed itself until I got out of class one night about 10:00 and the battery was dead! Called wife.com and she brought out the jumper cables. I got the car started and made it about 5 miles and it refused to run. Jump, leave cables hooked up for a few minutes to charge, drive 5 miles, jump... This procedure was repeated for the 20 miles it took to get home!
The problem fixed itself by burning out the idiot light! It turned out to be bad solder joints on the diode stack in the alternator. I reslodered, put in a new idiot light and all was right with the world. Man, I hate Lucas electrics...
Later,
Justin
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Hmmm. I think it works like this. The steering diodes in the instrument cluster are used to isolate the other idiot lights from each other and the battery lamp, yet allow the lamp test feature to work when power is applied and the small red lead is something less than 12V, near ground at engine off.
When the red lead goes low (not open) but low like when it shorts to the clamp under the damper, Yogi says it is just like lamp test all over again. All the idiot lights pass current through their isolation diodes to the ground out there by the alternator. If the diodes weren't there, then the oil pressure sender would light all of them when you lost oil pressure (probably a good feature for at least one of my family).
I suppose if you have experience keeping a British car electrically sound, you can abide the Bosch/Hella/Cibie/VDO stuff.
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Art Benstein near Baltimore
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Art, now that you've explained how the "self test" works it all makes total sense. I didn't know/hadn't thought about just how that all worked, wasn't aware that with no alternator output this line would look like a return to the rest of those.
I will now be able to sleep peacefully tonight. Really, crap like this sometimes keeps me awake thinking about it! You wouldn't believe how many times I've woke up a 2 AM with a solution to some computer problem I had been hacking around the day before. ;-)
Wife just got back from gassing up the Brick and said everything was fine but apparently I didn't tighten the alternator belts enough and it's "chirping". Hmmm, one step closer to proving the hypothesis...
Justin
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to be sure it's the brushes and not something else.
With the engine idling, all the warning lights should be off. Have a helper watch the warning lights while you pull the thin red exciter wire off the alternator.
Lights should not change. Then ground the red wire and see which lights come on. The oil light should not. If it does, something else is going on.
If the oil light stays off, the problem is in the exciter circuit: Thin red wire...to... Brushes...to...slip rings...to...alternator frame...to...block ground circuit.
Regards,
Bob
:>)
PS When I got brushes only, from alloemparts, I think - I got three sets (have 3 240 drivers) just to make the shipping cost more effective.
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Bob, sounds like a good test. Everything looks OK now, all idiot lights come on when key turned to run and they all go out after the Brick starts.
This is my only Volvo so I might stop by the Black and Decker refurb place in town (if it's still there) and see if they might have some brushes that are the same size. I've gotten brushes that would fit the carriage drive motors in TI-820 printers there a long time ago!
Now I have to figure out why I only have 4 injectors squirting on the D-Jet injection on the old Mercedes 450SE, anybody wanna help?
Being punished for something in a past life...
Justin
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Check out Mercedesshop dot com and check the Vintage forum. So a search first because someone else has certainly had your problem.
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Warren Bain - '99 V70GLT G-Valve > 70K mi, '96 965 >110Kmi Wifemobile near Manassas Va.. Check the 700/900 FAQ via the 'features' pull down menu.
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Thanks, that looks like an excellent site.
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Justin, I was wrong-- B.C. is right, the oil idiot light is not one of those wired to the lamp test steering diodes in the cluster.
The oil pressure is its own circuit test, as the sender switch shows it is zero before starting the engine. I chose the wrong idiot lamp for my example.
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Art Benstein near Baltimore
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The price from the mail order place was $2.00 a set, maybe still is. How can you beat delivery to your door? Get two sets, to have one in case things get crosswise working on the first one.
Re: MB - how many injectors are supposed to squirt fuel? Four is OK on a 4cyl. HoHoHo
Past life? More likely a dearth of atmospheric positive ions (or is it negative? I forget).
Regards,
Bob
:>)
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Unfortunately this one has 8 cylinders. :-P I have been fighting with it for four weekends (it's 150 miles away) just to get it to the point it will at least caugh on occasion. It has been sitting for about 20 years. After taking apart the fuel pump and getting it working, flushing the fuel system, two new fuel pressure regulators, rewiring most of the top half of the engine (critters were living in it and ate most of the wiring), and replacing a $hitload of fuel and vacuum hoses there's not much left. I have it narrowed down to either the ECU or there is a set of contacts in the bottom of the distributor that they call impulse triggers that I think kinda give the ECU a hint as to about when the injectors are supposed to fire then the ECU decides how long to squirt.
Believe me, I'd rather work on K-Jet any day of the week. I tried to get some help on one of the Mercedes lists and I basically got, "Good luck finding somebody that knows how to work on D-Jet!" That really got me pumped...
Justin
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You're getting dangerous with that digital camera!
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Don Foster (near Cape Cod, MA)
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...but I learn it from you (smile).
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Art Benstein near Baltimore
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Speaking of digital, keep that up and I'll show you a digit...
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Don Foster (near Cape Cod, MA)
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Like the one I occasionally see used in place of the old style directional signals these days on the expressways? (smile)
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Art Benstein near Baltimore
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Yeah -- I think it's Saddam's "good luck to you" sign. We seem to get it lot.
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Don Foster (near Cape Cod, MA)
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"...putting a new brush/regulator assembly in the alternator. Problem solved, WHY!!??"
The old brushes were worn enough so that they just barely touched the slip rings. This meant that they were energizing the alternator just enough so it would output a trickle of current to the battery. The flickering you saw in the indicator bulb was because the charging current was dithering around a few amps -- not enough to fully charge the battery, but just enough to provide running current to the system.
Your battery would have expired soon, particularly driving at night in the cold with the wipers going (BTDT). And a million miles from civilization and cell towers.
You could have soldered replacement brushes into your original assembly, but replacing it all is a safe approach.
"...wife calls it a serious psychological flaw..."
Being perceptive and curious enough to catch a problem in the nick of time, before it catches you, is a "psychological flaw?"
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Don Foster (near Cape Cod, MA)
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The psychological flaw would be not wanting to leave well enough alone and just accept that something is fixed!
I thought about doing just brushes but snagged a Bosch replacement assy. off "that auction site" for $20 including shipping so I didn't think I had anything to loose.
I could understand just the battery light flickering I'm just trying to resolve in what brain cells I missed killing off in my youth why ALL of the idiot lights would be dimly lit/flickering. But, looking at all of the diodes in the instrument cluster wiring diagram I suppose about anything could happen...
The only thing of note is that the old regulator assy was a small round job while the replacement was a large rectangular piece.
Oh well, it's happy now!
Justin
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Well regulators do go bad... and this is what they do. I guess I would have taken a voltage reading before I threw a harness in it but hey, if you needed one, it needed to get changed anyway, right?
Be glad the parts lasted this long. Most other 1983 cars are long gone. Yours has a lot of life left.
I don't know, it was just its time to go. The brushes really could have been at the end of their travel, or a wire was broken- who knows. COuld have just been a screw connnection and you cleaned it up enough by replacing it.
I just had the original ring terminal break off the big power lead on the back of my '86 alternator... I guess 210,000 miles is a reasonable expectation for such a part. Brass pieces definitely do get brittle with high temperatures. If I was inspired, I'd pull out the regulator and have a look at the brushes... but that sounds too much like work. Maybe next oil change.
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Rob Bareiss, New London CT ::: 86 244DL, 87 244DL, 88 744GLE, 91 244: 808K total
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I had put a meter on it a while back and everything was fine, and like I said I've never had a charging problem it's just that the idiot lights all being on dimly and flickering was somewhat irritating.
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