GEM wiring changes
I believe that there were significant wiring changes in 1998. Here's what I got from my 1996 wiring diagram:
C280:
1, dk blu/org, defrost switch in
2, wht/ppl, ctm diagnostic in
3, ppl/lt grn, door handle switch in
4, wht/ppl, lift gate in
5, lt grn/yel, LR door ajar in
6, pnk/lt blu, RR door ajar in
7, gry/red, RF door ajar
8, yel/blk, LF door ajar
9, blk/org, door ajar ind cntl
10, blk/pnk, key in ign sw
11, wht/blk, park/headlamps on in
12, yel, fasten belt ind crtl
13, lt blu/org, interval/delay wash in
14, blk/wht, gnd
15, blk, park sense
16, pnk/lt grn, door unlock relay cntrl
17, dk grn/ppl, door disarm in
18, gry/lt blu, wiper speed crtl
19, yel/wht, brake/run relay crtl
20, tan/yel, sound tone in
21, gry/red, signal return
22, pnk/yel, wiper mode select sw
23, brn/lt blu, seat belt warn sw in
24, tan/red, wsher pump crtl
25, lt blu/wht, diagnostic in
26, blk/wht, gnd
C281:
3, lt blu/wht, door ajar out
4, ppl/yel, rear wiper park sense
6, dk grn/ppl, rear wiper high sense
7, lt blu, rear wiper low sense
8, lt grn, rear wiper up relay
9, brn/lt grn, illuninated entry out
10, tan, rear wiper down relay cntrl
11, ppl/org, air ride control in
12, pnk/blk, rear wiper mode select in
C282:
1, lt grn, speed sensor pwr
2, pnk/lt blu, anti-lock break in
3, pnk/lt grn, 4x2 cntr axle sol cntl
4, brn, 4x4 axle disconnect sw in
5, lt blu, rear speed sensor in
6, blk/lt grn, front speed sensor in
7, dk blu/yel, 4x4 center axle sol cntl
8, wht/lt blu, 4x4 mode sw in
10, lt blu/blk, 4x4 low range ind cntl
11, dk blu/wht, 4x4 low signal input
12, yel/wht, 4wd contact plate out
13, lt grn, brake on/of sw in
14, gry, 4x4 high range ind cntl
15, yel, torge-on-demand out
16, gry, 4-lo to 4-hi relay cntl
17, brn/pnk, 4-hi to 4-lo relay cntl
18, org/wht, contact plate D
19, brn/wht, contact plate C
20, wht, contact plate B
21, ppl/yel, contact plate A
22, red/wht, gnd (M/T), neutral sense in (A/T)
C283:
2, org/wht, current sense low
3, tan/lt blu, down in
4, wht/blk, up in
5, wht/yel, power-battery
6, gry/yel, ignition(run)
7, yel/red, one-touch down relay ctrl
8, tan/yel, battery saver relay ctrl
9, gry/blk, vehicle speed sensor in
10, gry, current sense high
11, wht/yel, power-battery
12, lt grn/org, interior lamp relay ctrl
14, red/blk, ignition (start)
15, blk/pnk, ignition (acc/run)
16, org/yel, defrost relay ctrl
17, lt blu/red, acc delay relay ctrl
18, blk, gnd
