Some "known" problems in the dash:
1. clock goes off when turn signal is engaged, no interior lights (1988 928s4) : Fuse 7 bad
2. alarm on, no speed indicator, turn signal triggers fluctuation of the oil pressure meter (1988 928s4) : Fuse 10 bad
3. signals stay on or erratic behavior, just after starting: switch engine off/on again. Reset problem!
4. digital instrument just horizontal lines, no dash lights (1989 928s4) : Fuse 24 bad
All my digital functions (including Odometer) have suddenly gone on "the blink"!! All I get is a series of horizontal lines in the three LED displays at the bottom of the instrument pod.
Has anyone experienced? Is the whole instrument panel shot or is there a separate circuit board for the digitals?
Left the car out overnight in extreme cold (needed the garage to work on another car) and when I re-started the displays did all kinds of funky things then just settled into the horizontal lines.
Any advice appreciated!!
89 S4 5spd Dunkelblau
One possibility is low voltage - could be low for the entire system,
or could be that the digital dash is seeing low voltage because of a
bad connection (power or ground) due to the cold. I would use a
voltmeter to check the system voltage, and see if it is 13.2 or
higher, If so, I would then check the power and ground connections for
the dash, especially on the
flexible circuit board. Or just wait until it gets warmer...
Check fuse #24.
That did it!!! The fuse was actually fine, but pulling it and reinstalling
reset the dash!! Funny, because disconnecting the battery for 24 hours did NOT.
89 S4 5-spd Dunkelblau
Glad that solved your problem. Must people do not know that fuse 24 (89) also controls the instrument cluster. It is also the fuse for the interior lights and it is common for this fuse to get popped when someone messes with the interior lights. In your case it was simply a "corroded or dirty" fuse connection. I suggest changing that old fuse anyway.
Tip of the Day : If your 89-up instrument cluster goes out AND your interior lights stop working, replace the fuse for the interior lights ! 89 is Fuse 24, 90-95 is Fuse 25.