MACS Monthly Newsletter - 2017 - FEB8

unreasonable thought-but with the direct connections it seemed that the temporary harness was
okay.
He reviewed the harness diagram for HVAC but
nothing struck him. He checked for the possibility
of an aftermarket accessory installation somewhere
under the dashboard, but nothing there. As a dealer technician he had access to dealer special tools,
including the GM terminal fit test kit. He pulled
it out and checked every terminal in the circuit he
could reach. Nothing there.

Finally, the answer came in the form of a recollection from another technician: there are two outside
air temperature sensors, one for the mirror 's temperature indicator, a second for the HVAC system.
The one he had been using was for the mirror. The
sensor for the HVAC was on the right front behind
the bumper filler, close to the end of the bumper
(FIG. 10). Sure enough, replacing that sensor restored normal operation. This was a special toughie because the first (mirror) sensor doesn't show up
on the HVAC diagram. ■

DEAD BATTERY OR VERY-LOW VOLTAGE
spindles in the caliper, and turn the spindle clockwise to
release the brake (yes, the parking brake will have to be
reset after repair work is done). ■

zendextool.com/gojak-2

Moving a car with a dead battery or very low voltage
has not been a problem until recent years. However,
you've surely noticed that a number of late-model cars
have electronically controlled transmission shift mechanisms-no more cable or linkage connections. If the car
is left in forward gear, that's usually no problem. If (as
would be normal) it's in Park, you have to turn on the
ignition, apply the foot brake and press and hold the
Shift Interlock button. But if the battery is dead or nearly
dead (under 9 volts), you should be prepared to charge
or boost start it. If the car is in an awkward location, such
as in the shop driveway, etc., and there's an electrical
issue that makes it impossible to boost start or at least
complete the ignition circuit with the vehicle positioned
where it is, you have a problem. You should be prepared
to face the problem of moving it into a work position in a
service bay. The simplest way to move the vehicle is with
hydraulic dollies (a set of four, one for each wheel). They
include a hydraulic jack for each dolly. If you aren't familiar with these dollies, check with a body shop, which
uses them to position really damaged cars. GoJak (FIG.
11) is the oldest one on the market, but we suspect there
are less-expensive ones, with non-hydraulic jacks, that
might suit your needs and budget.
Under some conditions a car's electrical parking actuator will default to Park, and be stuck mechanically in that
position. As an example of what might have to be done
(GM system), you must remove the actuator and slip a
hex wrench past the splines of the actuator piston apply

Figure 11: GoJak units were probably the first to permit moving a car/
truck that was locked in Park. They were introduced about 20 years ago,
initially for body shops.

MACS Service Reports is published monthly by the Mobile Air Conditioning Society
Worldwide. It is distributed to members of MACS Worldwide and is intended for
the educational use of members of the automotive air conditioning service and
repair industry. Suggestions for articles will be considered for publication, however,
MACS Worldwide reserves the right to choose and edit all submissions.

Editors:
Elvis Hoffpauir, Steve Schaeber
Production Designer:
Laina Forcey
Manager of Service Training:
Steve Schaeber
Mobile Air Conditioning Society Worldwide
P.O. Box 88, Lansdale, PA 19446
Phone: (215) 631-7020 * Fax: (215) 631-7017
Email: membership@macsw.org * Website: www.macsw.org

Unless otherwise noted, all photos/art by author.

February 2017

MACS Service Reports

http://www.zendextool.com/gojak-2/ http://www.macsw.org

Table of Contents for the Digital Edition of MACS Monthly Newsletter - 2017