1995 Windstar - will crank but won't turn in dew conditions

Hi group,

I just spent some time replacing a bunch of radiator hoses on my
WIndstar which required me to disconnect the spark plug wires at the
ignition coil - the Ford factory manual says that you MUST apply
Silicon Dielectric Compound to the contact areas at either end of the
spark plug wires if you disconnect them for any reason - this SDC
stuff, I understand, is an insulator (moisture) that also serves as a
lubricant for the next time you pull the wires. At first I ignored the
warning and just reconnected the wires to the the ignition coil and the
Windstar fired up just fine but after I parked it in the garage for
awhile (in which the clothes dryer vents causing condensation all over
the garage), the Windstar would crank powerfully as usual but not turn
over. Recognizing the most likely culprit, I got a packet of SDC,
enough for a finger tip per connection, and appled thinly to both wire
and coil connectors (and opened the garage door to vent the moisture)
after awhile, the Winstar turned over and all was well. Now, when the
car is parked out on the driveway overnight (30's and 40's temp), I get
the same problem. Car will turn later in the morning after all the dew
dries up...

QUESTION 1: Is there a special way to apply this SDC stuff?
QUESTION 2: Should I also consider an electrically conductive compound
and apply it to the metal connections only? If so, what type of
compound?

Your wise consideration and advise will most certainly be appreciated!

Kev

wrote in article
om>...
> Hi group,
>
> I just spent some time replacing a bunch of radiator hoses on my
> WIndstar which required me to disconnect the spark plug wires at the
> ignition coil - the Ford factory manual says that you MUST apply
> Silicon Dielectric Compound to the contact areas at either end of the
> spark plug wires if you disconnect them for any reason - this SDC
> stuff, I understand, is an insulator (moisture) that also serves as a
> lubricant for the next time you pull the wires. At first I ignored the
> warning and just reconnected the wires to the the ignition coil and the
> Windstar fired up just fine but after I parked it in the garage for
> awhile (in which the clothes dryer vents causing condensation all over
> the garage), the Windstar would crank powerfully as usual but not turn
> over. Recognizing the most likely culprit, I got a packet of SDC,
> enough for a finger tip per connection, and appled thinly to both wire
> and coil connectors (and opened the garage door to vent the moisture)
> after awhile, the Winstar turned over and all was well. Now, when the
> car is parked out on the driveway overnight (30's and 40's temp), I get
> the same problem. Car will turn later in the morning after all the dew
> dries up...
>
> QUESTION 1: Is there a special way to apply this SDC stuff?
> QUESTION 2: Should I also consider an electrically conductive compound
> and apply it to the metal connections only? If so, what type of
> compound?
>
> Your wise consideration and advise will most certainly be appreciated!
>
> Kev
>
>

It may well be a good idea to just replace the wires, 1 wire at a time, to
not miswire it. I replaced mine, on my 1995 Saturn a few years ago ( it was
missing a little on humid/rainy days ). The wires were silicone from
AutoZone, and had dielectric grease in the ends, and fit well. Also, check
for corrosion at the coil terminals ( usually white powder). You can
usually remove it with a dry stiff toothbrush, else get a *plastic-bristle*
gun cleaning brush that looks like toothbrush but stiffer. Dont use any
liquids or cleaners or abrasives besides plastic bristle brush.

Once the wires start to break down, either from age, stress, skin oil,
bending to put on, moisture etc..., they are nothing but trouble, even
though fine on dry days usually ! I cant recommend wire brand, because my
box got lost 3 years ago, but they must be good as dealer wires.

Thanks for the response Tim.

Funny thing is that we had the wires replaced about 4 years ago when,
you guessed it, the WIndstar was not starting on rainy/dewy days. The
wire replacement did not solve anything unfortunately so I had to take
it to a mechanic. He put a big tub of water under the engine and heated
it up to a boil with a couple blow torches and then did some electrical
continuity testing. He discovered that the wiring harness bulkhead
(firewall) connector was the culprit. He disconnected the bulkhead
connector, blew it dry, then gobbed on Silicon Dielectric Compound and
reconnected. Problem solved for 4 years (that's why I'm fixated on this
SDC stuff). The reason that I doubt the wires is because they are in
great condition, and this sympton only started AFTER I had removed and
replaced the plug wires from the ignition coil (w/o SDC).

I called my mechanic after my first post and he reiterated that you
have to gob on the SDC on the coil connectors and wire boots to make
sure you have a water tight connection. I think that's my problem as I
only had a tiny packet - I will go ahead and gob on the SDC this
weekend and post the results after my first dewy morning.

Kev

OK - so on a warm dry day, I pulled the wires off the coil, wiped them,
cleaned out the coil connector pits, roughed up the metal contacts on
the wires with 150 grit sandpaper, reapplied Silison Dielectric
Compound to the inside rubber boot portion of the boot just above the
metal contacts (this is where the boot meets the coil connector rim)
and reinstalled wires.

Today on a slightly dewy morning, I cranked it - it turned on the 2nd
crank. Encouraging, yes, but it cranked immediately on the dry day. I
am continuing to monitor.

Results just in:

After wating for the right rainy/dewy conditions to test my situation I
have found that the solution is the *heavy* application of Dielectric
Grease on the ignition coil contacts (electric harness contacts and
spark plug wires). I tried to apply it sparingly (cuz I had this tiny
tube of grease) but had another no-start on a dewy morning - after air
blowing the ignition coil connectors with compressed air that dewy
morning, the Windstar turned - I knew I was on the right track. That
night, I bought a *big* tube of Dielectric Grease and slathered on the
grease heavy with a toothbrush covering everything - including the
electric harness connector contacts that supply power to the ignition
coil. Problem solved. Starts on rainy and dewy mornings alike just as
if it were dry and sunny. Hope this helps someone out there - 2 words:
DIELECTRIC GREASE.

PC