I have a 92 300te and all the lights pulsate and the frequencies
change with the speed of the eng.
Is this a sign the alt. is about to die.

Thanks:

I'm not an electrical genius, but it sounds like a symptom of a problem with the alternator. It may not be quite ready to go south though, as the regulator, internal diodes, or brushes (if yours has them) may be causing the problem.

First thing to do is to check the voltage at the battery. Have someone rev the engine up to 1500 rpms or so and see if the voltage gets to about 13.5 volts or more. Also test with accessories on (A/C, headlights, radio, etc). It should be able to maintain about the same voltage, but no more than 14.

Also, a slipping belt could cause problems. Check that as well.

Just replaced the alternator on my 300E this weekend...it had a bad regulator and was pushing 17.5 volts!!! Wouldn't wish that DIY job on anybody, so I would look for all causes other than the alternator...good luck!

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car

Are the regulators on that one internal? I've replaced the regulator twice on my 300D. It just screws onto the back of the unit.

__________________
Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
'89 190D - 120,000 miles (sold)
'85 300SD - 317,000 miles (sold)
'98 ML320 - 270,000 miles (sold)
'75 300D - 170,000 miles (sold)
'83 Harley Davidson FLTC (Broken again) :-(
'61 Plymouth Valiant - 60k mikes
2004 Papillon (Oliver)
2005 Tzitzu (Griffon)
2009 Welsh Corgi (Buba)

yes I would say you definetly have a alternator that is on its way out if its not gone already.I would take the car to auto zone and have them check the alternator on the car for you to find out for sure then figure out the next step may its a regulator .

I suspect your alternator has an internal regulator (pity because it's a much less expensive repair).

Nevertheless, FastLane carries the rebuilt Bosch alternators for around $140 + $75 core charge. If you don't mind doing the work yourself, you can save a ton of $$$. Probably cheaper than taking your original to a shop to get rebuilt. The rebuilt unit out of the box looks brand spanking new!

If you choose to DIY, you will have to remove the sepentine belt to do the job properly...replace the belt while you're at it...$30.

__________________
2009 ML350 (106K) - Family vehicle
2001 CLK430 Cabriolet (80K) - Wife's car
2005 BMW 645CI (138K) - My daily driver
2016 Mustang (32K) - Daughter's car