You must go back to a regular bulb for the brake wear and brake warning indicators also. Do that and report back if it fixes the problem.

VR says Bosch on it.

The charge bulb is installed, and even though voltage at battery is 13.8, the charge bulb does NOT come on with key on engine off. I have never seen it on. I did take it out and tested it and the bulb is ok.

Cool, will do

That's not right! Do this test and report back:

Remove alternator connector, ground the blue wire to the alternator case with key on, engine off. Charge indicator should illuminate.

This light not turning on is why the alternator needs elevated engine speed to start charging. The light / blue wire wakes up the alternator before it starts spinning. Some regulators have a back up circuit that will allow the alternator to start charging without this wire. ( and residual magnetism in the alternator can get thing rolling. )

Where is the problem, then? The VR?

- Replaced the brake wear light and brake light with regular incandescent bulbs.

- Fixed the problem with the radio cutting out - the previous radio had the speaker "-" combined and I followed the wire till I found the separate speaker "-" wires for left and right; I can have it super loud now

- New VR is on order

- New door strikers are on order

- The clock is waaaaay slow. Like, maybe 10 minutes per hour slow. Otherwise things are slowly improving!

Did you ground the blue wire as stated in post 19 by Funola to see if charge light comes on?

The clock has two 100uF 16 volt capacitors that should be changed.

What did you use for LED backlighting for the instruments? Nothing to do with your problem but I would like to improve the lighting in a neighbour's 123 coupe.

Not yet, the cluster is out of it right now because I am back to troubleshooting the clock (which is the original reason I took everything apart)

I replaced those, and the clock seemed to be working. I will leave it on overnight, hooked up to 12V, on the bench, and see what it does


I used this: https://www.superbrightleds.com/moreinfo/miniature-wedge-base/194-led-bulb-5-smd-led-tower-miniature-wedge-retrofit-car/206/

I had to re-arrange the leads because they wrapped around on both sides and therefore if left untouched would've simply shorted the socket. Its definitely brighter than the original bulbs.

If you unplug the blue wire, ground it then turn the key to the run position, the dash charging light should light. If it does not, that circuit needs fixed. This test is independent of the alternator functioning or even in the car at all.

Why did you order a new VR? Your alternator was bench tested good. That means the VR in the alternator is also good. The only thing to check is the carbon brush length on the VR is within spec.

"regular LEDs" I hope that is a typo and you meant regular incandescent bulb.

Oh, you know, got carried away with the "swap parts until its fixed" kind of thing... well, at least I will have a spare VR.

Yes sorry I meant incandescent bulbs.

Tomorrow will put the instrument cluster back in and do the blue wire test.

Have a theory why clock was running slow: the adjustment gear shaft was binding and so the clock adjustment mechanism was creating a drag. I disassembled and cleaned the adjustment mechanism, hooked it up to 12V, set the correct time, will check tomorrow.

In all my years of driving, I have never had to buy a VR because I never had one go bad. The brushes wear and I just replace the brushes when they get too short.

You aren't understanding how these alternators work, thus ignoring the many suggestions. They are confusing. Same Motorola-style was used on 70's GM (google). They generate the field current internally. That circuit requires a "boot-up" current, which comes from the "battery" lamp. In 1984+, a few other lamps (brake pads, low fuel) add to boot-up current, but apparently as a "bulb check" function for them. An LED will not supply enough current to boot-up at idle. Doesn't mean you can't use LED's (I do). As mentioned, there is usually enough residual magnetism to boot-up once you rev to ~1500 rpm. The lamp should then go off. The Owner's Manual states if it doesn't turn off - emergency trip to dealer. BTW, appears others are misreading what your wrote - "lamp not on with key off". That is good.

With LED's you have a 50-50 chance. They are all polarized. Just turn 180 deg until they light. LED's that shine forward are especially good for the "light tunnels" that light the speedometer and tachometer. Look closely because M-B bulb holders are different. Some LED's will short-circuit the holder, which will fry a trace on the dash circuit board (how would I know?). Test first w/ a multimeter.

It is not my intention at all to ignore suggestions; the only thing i haven't done so far is the blue wire test and that's because I took the cluster out so that I can leave the clock hooked up overnight and its mechanism needed cleaning. That's the next thing I'll do when I get home tonight.

I did go back to plain bubs for both of the brake lights.

Yep, all my LEDs were exactly that way - the leads wrapped on both sides of the flat part, and if installed that way it would have short circuited. I tested them all with a 12V source beforehand and was thus able to made modifications and avoid that particular pothole.

For what it's worth, the charge light has never worked on that car, it's just that this time I finally got tired of it not working and figured while I am poking around the instrument cluster I'd get a crack at fixing it too... Remember this whole project started as "I want to fix the clock"... :D