MACS Service Reports - 2015 - FEB7

THERMOMETERS
Most shops have several thermometers, including
an infrared, maybe even two (one with laser sighting). We tend to rely on temperature readings a lot,
but few technicians bother to ever check them. So,
unless they go way off where it's patently obvious, they continue to be relied on. It's easy enough
to check a thermometer in a pot of boiling water
(212°F) and against an ice cube (below 32°F). But it
just doesn't get done. Maybe the best answer is to
take them all home some evening a couple of times
a year.

The infrared is particularly important, because it
doesn't measure air temperature and the readings are
particularly sensitive to location, which is why a unit
with laser sighting produces better readings. But in any
case, when you use one, aim it at a specific surface, because as noted, infrared technology doesn't measure airtemperature. Those infrared units that have been sold for
general garage use that claim to measure air temperature
actually have a tip made to reach ambient temperature
almost instantly and the sighting beam is actually reading the temperature of that tip. ■

EVAPORATOR CORE REPLACEMENT: YES OR NO

motorcraftservice.com

Here we are, back to the platform for the Ford
Crown Victoria/Mercury Grand Marquis and Lincoln Town Car. In particular, the Lincoln Town Car
is a vehicle that is kept in service almost forever,
because of its popularity in limousine/livery service. Ford has discontinued the "Panther" platform,
which also was the base for the Ford Crown Victoria police car and the Mercury Grand Marquis sedan. Because of the types of operation, these cars
get a high amount of A/C operation, so perhaps
that explains the relatively higher leakage failure

rates of evaporators. The access is reasonably good.
No need to work under the dashboard except to remove housing retaining nuts. The housing itself is
in the engine compartment, and the typical procedure for access is to remove the right side fender
liner, make heater hose and refrigerant line disconnections, unplug the blower connector, and remove
the cowl grille assembly. Then disconnect the evaporator tubing connections and unbolt the housing
from the cowl (Figure 8).
The technician checks with the Ford dealer and
he's told that a new evaporator
for the Town Car is only available
as part of a complete housing. The
price is not out of sight, but it isn't
pocket change either; close to $500,
although it requires transferring
some parts from the old housing.
Yet if you look at the housing,
you'll see a top cover or maybe a
split housing (Figure 9), so there is
access to the evaporator. However,
in the case of the Town Car/Crown
Vic/Grand Marquis series, the situation has varied over the years.
That is, in some model years the
housings came apart for evaporator replacement, and in other years
they did not. We were able to check
Ford service information on these
cars back 10 years (to 2004). Production ended with the 2011 models.
Unfortunately, we can't guarantee
that the type of evaporator housing
Figure 8: Crown Vic/Grand Marquis/Town Car HVAC housing is accessible from under hood. Lots specified for a model year is what
of fasteners to remove, including some under-dash, but overall access is reasonable. The evaporator you'll actually find on the car. The
and case may be available only as an assembly.
series was little changed during

February 2015

MACS Service Reports

http://www.motorcraftservice.com

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