Tacho conversion

[Whitey]

If you want to convert from a non tacho instrument cluster to a GX model with tacho and you cannot get the GX wiring harness the attached document will assist in doing the coversion.
cheers
whitey

[wagonist]

I've just done this for a 2nd time.

There are some errors in Whitey's description.

Pin (Standard) --> to Pin (GX)
15 --> 17 (not 18)
16 --> 18 (not 20)
18 --> 20 (not -)

Also for interest, these are what the wires do
Pin standard (pin GX) wire colour: task
1 (3) RY: door
2 (2) BR: door
3 (27) GY: coolant temp
4 (4) LR: seat belt
5 (6) LR: park brake/brake fluid level
6 (7) Pi: ignition start
7 (9) ??: air bag
8 (10) Y: speed signal
9 (13) RB: high beam
10 (14) RY: high beam
11 (12) Br: alarm/chime
12 (11) G: left indicator
13 (15) Y: speed signal
14 (16) RY: air bag
15 (17) ??: ??
16 (18) L: low fuel
17 (19) GB: oil pressure
18 (20) YB: check engine
19 (21) YG: ABS
20 (8) L: ignition ON
21 (22) W: automatic overdrive off
22 (29) B: earth/ground
23 (26) ??: (blank)
24 (23) GY: right indicator
25 (28) ??: automatic gear hold
26 (--) ??: (blank)
27 (24) B: fuel level
28 (--) ??: (blank)
29 (1) GW: dashboard illumination
30 (30) GB: dashboard illumination
-- (5) ??: tacho

There is already a tacho wire in the car loom from the ECU loom to the body loom (wire colour changes from BrW to W) and then to where the dashboard plugs in, just no wire from there on.
The wire to the dashboard is in the blue plug, in the row of 2 x 5pins, the middle one (pic attached)

I used the automatic overdrive off wire for the tacho wire pin 21 (22).
The other end of this is in the white plug where the dash loom meets the car loom. So I pulled the overdrive wire out of the white plug & put it into the blue one. No messy soldering :clap:

[wildwesty]

Have just completed this excercise and found this info very useful.

Cheers Kevin.