AUII No speedo or tacho, low fuel & high temp lamps staying on

[Coops2310]

I have done a search of forum but have not found anything relating yet.

2001 AUII Forte wagon. 4.0L, auto, no ABS, driver & passenger airbag.

About 6 weeks ago, wife drove through a slightly flooded causeway & soon after engine ran rough & dash lost speedo, tacho & was missing bits of odometer display. Gave it a good blow down under bonnet, including coil pack, leads & electrical connectors. Engine ran smooth again but dash was the same. Removed & refitted both instrument fuses & that fixed the problem.

About a week later, engine ran rough again & dash played up. Found no spark at No 4 coil pack. Replaced coil pack & leads which fixed rough running. Dash still playing up, removed & refitted fuses. Odometer came good but still had problem with speedo, tacho & lamps. Airbag light not staying on or flashing code (comes on then goes off as normal) but put Snap-On scan tool on which brought up a airbag module fault. Cleared code & it came back within a minute.

So far I have checked charge rate - ok. Checked/cleaned earth points behind headlights, battery to chassis & to engine. Stripped down cluster & soldered any suspect dry joints. Replaced BEM & airbag module (under console). Also ran without airbag module & same problem present but airbag light stayed on. Have also noticed that speedo & tacho needles are free with ignition off but with ignition on they are hard to move. Have done a cluster function with scan tool & all lamps & guages work fine, including speedo & tacho.

I am thinking it could be an ECU short/spike ? or earth problem that is trying to get an earth from the the lamps & causing them to come on? Next step might be sitting down with wiring diagram & checking continuities of circuits ?

Any assistance would be appreciated.

PS. In relation to wiring diagam on forum, is there anyway they can be printed so I can trace them on paper rather than have to take laptop out to car?