[W126 Coupe] Strange gauge lights error, any ideas?

[Afzaal Khan.M]

a failing regulator ,replace and re -test
mak

On 24/02/2010, Josh Allen <heyallen at null-ptr.net> wrote:

> Markus,

>

> The new alternator was whatever I could get from the Napa warehouse

> store, since that was the only alternator available on short notice at

> the time.

> It had a new regulator with it, and at the time was putting out

> 14.5-14.7v when running, but I don't know currently.

>

> I'll check up on the charging system today, one way or another, I just

> couldn't when I found it yesterday evening.

>

> Thanks,

> Josh

>

> On 2/24/2010 2:45 AM, Markus Meyer wrote:

>> Josh,

>> I'd start by checking battery voltages, resting (car not on) and with

>> car running (this shows your alternator voltage), and go from there.

>> Any idea what alternator was put in, where it came from, was it new,

>> rebuilt, new regulator used, etc?

>> Once you rule out a charging problem, you can move on to other things

>> like the OVP.

>> Markus

>>

>> On Wed, Feb 24, 2010 at 2:27 AM, Josh Allen <heyallen at null-ptr.net

>> <mailto:heyallen at null-ptr.net>> wrote:

>>

>>     Ok, I have a strange fault in my 500 SEC currently, and I can't

>>     find any of the threads that I could have sworn I'd read on it.

>>

>>     When I start the car, the charging system indicator glows dimly,

>>     as well as the brake wear light and the empty fuel system light,

>>     but both of the latter lights are around half the intensity of the

>>     charging system light.

>>

>>     I thought I'd heard that these were indications of the OVP going,

>>     and it did have some nasty 'foamy' corrosion or flux buildup on

>>     the back of the circuit board which was easily cleaned off and

>>     then resoldered for safety's sake.

>>     The fault recurred two days after, but not immediately after

>>     having resoldered it.  (It even persists with the OVP completely

>>     removed, and no other issues seem to show up??)

>>

>>     The alternator was replaced around 2000 miles ago, due to the rear

>>     bearing failing catastrophically, but I haven't probed the output

>>     voltage yet, as today when I went to drive it and found the issue

>>     was persisting, it was raining heavily.

>>

>>

>>     Any ideas would be greatly appreciated, or even pointers on search

>>     terms that would point me in the right direction.

>>

>>     Thanks,

>>     -Josh Allen

>>

>>

>

>