Honda Acura NSX 1991 Service Manual page 1262

Rear Window Defogger
-Switch Light Bulb Replacement -
1 . Remove the steering column lower and upper cover.
2. Remove the 3 screws from the combination switch.
3.
4. Remove the rear window defogger switch bulb.
23-278
REAR WINDOW
DEFOGGER SWITCH
-Relay Test
Remove the defogger relay in the main fuse box.
2 . There should be continuity between the C and D ter-
minals.
3 . There should be continuity between the A and B ter-
minals when the battery is connected to the C and
D terminals.
There should be no continuitv when the battery is
disconnected.