(1) Disconnect the vacuum harness connector at
the back of the A/C-heater control (Refer to 24 -
HEATING & AIR CONDITIONING/CONTROLS/A/C
HEATER CONTROL - REMOVAL).
(2) Connect the test set vacuum hose probe to each
port in the vacuum harness connector, one port at a
time, and pause after each connection (Fig. 13). The
test set gauge should return to the 27 kPa (8 in. Hg.)
setting shortly after each connection is made. If OK,
replace the faulty mode control switch. If not OK, go
to Step 3.
(3) Determine the vacuum line color of the vacuum
circuit that is leaking. To determine the vacuum line
colors, refer to the Vacuum Circuit charts (Fig. 14)
and (Fig. 15).
(4) Disconnect and plug the vacuum line from the
component (fitting, actuator, valve, switch, or reser-
voir) on the other end of the leaking circuit. Instru-
ment panel disassembly or removal may be necessary
to gain access to some components. See the appropri-
ate service procedures.
(5) Connect the test set hose or probe to the open
end of the leaking circuit. The test set gauge should
return to the 27 kPa (8 in. Hg.) setting shortly after
each connection is made. If OK, replace the faulty
disconnected component. If not OK, go to Step 6.
(6) To locate a leak in a vacuum line, leave one
end of the line plugged and connect the test set hose
or probe to the other end of the line. Run your fin-
gers slowly along the line while watching the test set
gauge. The vacuum reading will fluctuate when your
fingers contact the source of the leak. To repair the
vacuum line, cut out the leaking section of the line.
Then, insert the loose ends of the line into a suitable
length of 3 millimeter (0.125 inch) inside diameter
rubber hose.
Fig. 13 Vacuum Circuit Test
24 - 18
CONTROLS
TJ
A/C HEATER CONTROL (Continued)