Uh... Printed Circuit Board perhaps?

On Wed, Feb 6, 2013 at 1:54 PM, Scott Daniel - Turbovans
<scottdaniel@turbovans.com> wrote:
> Igather that by PCBs you don't meanPolychlorinated Biphenyls
> <http://www.epa.gov/pcb/>
>
>
> On 2/6/2013 1:00 PM, David Beierl wrote:
>>
>> At 03:12 PM 2/6/2013, neil n wrote:
>>>
>>> Thanks Dick and David.
>>>
>>> Thanks *very* much for insights into what may have happened. Yes,
>>> maybe that solder joint was re heated. The insulated female terminal
>>> from 30 to relay shows what may be a slight small burn mark.
>>
>>
>> Well it certainly got hot enough to melt the solder around the
>> terminal, but that was from high resistance and arcing once the joint
>> had already gone bad.  The flux residue around the solder pad also
>> suggests that it may have been reworked/reflowed -- i.e. repaired --
>> previously, which is what Dick was talking about.  That would have
>> been done on the bench and not affected the female terminal.
>>
>>
>>> The replacement 109 relay is a different design; the pins go directly
>>> to the internal parts. Which begs a question:
>>>
>>> How do I know which way the relay box goes back on the relay base?
>>
>>
>> VW relays with PCBs have a pair of molded-in rails inside the cover,
>> that the board slides into to support it against overall
>> distortion/vibration.  Failing to mount the cover in this orientation
>> will contribute to terminal failures.
>>
>>
>>> Since this was my first time at a swap (or work of this magnitude), I
>>> went with OEM wherever possible. I assumed the 109 relay had some more
>>> complex electrical "voodoo" going on so I made a point of using that
>>> part. Same with fuel pump relay. The ABA fuel pump relay has large
>>> 30-87 terminals and a small 85 terminal (ECU) so a generic relay block
>>> was of no use. The 109 also has the small 85 pin. IIRC, I had been
>>> using a relay socket for the 109 along with a separate wire to 85 pin.
>>> Yes. Seems so. Image:
>>>
>>> https://sites.google.com/site/tubaneil2/PowerRelayDiagram.jpg I
>>> don't recall when or why I deleted this socket.
>>
>>
>> This relay according to the diagram on the side has an additional
>> component (likely a diode?) wired in parallel with the activating
>> coil.  This would likely be to protect the electronics driving the
>> relay from being fried by the voltage pulse when the coil is
>> de-energised.  You'll want to know what that component is before
>> replacing it with a generic relay (which you otherwise could by
>> taking a standard relay and connecting the 86 terminal to the 30
>> terminal.  This particular relay is operated by switching the ground
>> lead rather than the hot lead of the coil.  All this suggests to me
>> that it's being driven by an ECU output, is this correct?
>>
>>> type. They will fit a FLAPS type generic relay socket. Both the Jetta
>>> Power Supply and Fuel Pump relays have a suppression component
>>> (appears to be a resistor) in parallel on  85 and 86 so I would make
>>> sure a substitute relay has same.
>>
>>
>> Ok, how specifically does it appear to be a resistor?  What does it
>> look like, exactly?  Any numbers, banded end, color bands, body
>> material, body color, body shape?  I guess a parallel resistor could
>> be used to mitigate a voltage spike, I'm just not accustomed to the idea.
>>
>> Yrs,
>> d
>>
>