Hummer H1 Service Manual page 1043

13-38 Accessories
Diagnostics
Step
1 NOTE: The control box contains a timer
that will shut the heater off after one hour
of use. The switch must be cycled "OFF"
and "ON" to restart the heat cycle.
Turn ignition to the "ON" position. Posi-
tion the seat heater switch to one of the
heat positions. Does the switch illumi-
nate?
2 Cycle seat heater switch "OFF and
"ON". Do you hear an audible click com-
ing from the control box?
3 Check switch output power at the control
box connection. In high position check
for voltage on white and orange wires. In
low position check for voltage on white
wires.
4 Check resistance at terminals "A" and
"D" of 4 position cushion connector. Is
the resistance within specification?
5 Isolate the back element and check its re-
sistance. Is the resistance within specifi-
cation?
6 Check resistance of NTC heat sensor in
the cushion element. Is the resistance
within specification?
Call 1-800-927-6787 for additional trou-
bleshooting assistance.
_____________________________________________________________
Seat Heater Does Not Heat
Action Value(S)
Switch light Go to step 2.
"ON"
Audible Go to step 4.
relay click.
Approxi- Go to step 4.
mate battery
+ voltage.
3.2 W
Go to step 6.
+-10%
(resistance
of back and
cushion ele-
ment in
series)
1.2 W
Replace the cushion ele-
+- 10% ment.
10K W
Replace the control box.
+- 10% at
77° F
Yes
Check/repair fuse 3G cir-
cuit through the auxiliary
power point to the switch
"2B" and "3B" (red wire)
and ground circuit from IP
ground point to the control
terminal "2B" (black wire).
Check circuit between con-
trol "2C" and switch termi-
nals "7" and "8"(black
wire). If circuits OK and
switch is not illuminated,
replace the switch.
Go to step 3.
Replace the switch.
Go to step 5.
Replace the back element.
Replace cushion element.
®
No