"Bernd D. Ratsch" <fasstdak@hotmail.com> wrote:
: Just going from experience on these engines (long term - not just pulling a
: lead and seeing what changes).
No es possible, senor... I'm not sure if you read my post
or not, but I didn't just pull a lead and see what changes (?)
I removed the sensor and put an ohm meter between the body of
the sensor and each pin, individually. Result: there is
absolutely no continuity between either pin and the body of
the temp sensor. Long story short, this means that there
are only two possible ways that putting sealant on the
threads of the sensor can affect the signal output:
1) Things are very broken.
In order for the signal to improve when the body of
the sensor is grounded, all of the following conditions
must be met:
a) The sensor itself is broken such that one of
the pins is shorted to the body of the sensor.
I don't know that this is even possible, but
lets assume it is for the sake of this exercise.
We must also assume that whatever caused the
pin to short to the body of the sensor didn't
also damage the thermosister inside.
This is important because neither pin of the
sensor is normally connected to the body
at all, so we need a way to get to engine
ground.
b) The ground source from the PCM is broken;
either the pin on the PCM or a pin on the
sensor does not have a connection, or the
wire itself running to the sensor is cut.
This is important because if the PCM provided
ground path is not damaged, then the signal
would still be good, regardless of wether
the body of the sensor is grounded or not
because the normal circuit would be used.
c) Since the wiring harness connector can be
plugged in either way, it must be plugged
in such that the pin on the sensor which
is shorted is NOT plugged into the side
of the connector which contains the voltage
reference signal from the PCM.
This is imporant because otherwise, this
would result in shunting that voltage
directly to ground. This might blow a fuse
or burn something up, but in any case will
not result in a good signal, which is what
we're shootin' for here. (Hey, at least
with this one you've got a 50/50 chance,
which are the best odds you're gonna see
in this whole deal.) ;-)
d) The ground that the PCM is using for the
sensor must be connected to the engine
ground. This is most likely already the
case, I include it here simply for
completeness.
If all four of the above conditions are met, there
is the potential that the alternate ground path
provided via the body of the broken sensor could
be used instead of the provided ground path from
the PCM, and thus conceivably, putting sealant
on the threads of the sensor could block this path
resulting in an errant signal.
2) You have the ability to alter the laws of physics.
--
-Jon-
.-- Jon Steiger ---- jon@dakota-truck.net or jon@jonsteiger.com --.
| 1970 Barracuda - 1990 Dakota 'vert - 1992 Ram 4x4 - 1996 Dakota |
| 1996 Intruder 1400 - 1996 Kolb FireFly - 2001 Ram QC 3500 CTD |
`------------------------------------ http://www.jonsteiger.com --'
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