Whenever i turn the headlight switch on the trip odometer and miles to e functions go blank. All other dash lights function properly, the odometer continues to record mileage correctly, its just not visible when the headlight switch is on. Any ideas?
try this though......... when you turn on you r headlights try hitting the underside of the dash just under the tripometer.... see if it comes back on... it might just be a loose conection......... if it is its an easy fix, just pull it and drop some solder on there........
On my 86 NA w/digi dash when the lights are on, the trip odometer and avg. speed, distance to empty readouts are not as bright. But they all function. In the daytime if I have to use the headlights, I can basically not see them --especially if I have sunglasses on. I think that's a function of them being dimmed by the system so they aren't so bright when all the other lights are on. I have noticed that with LED displays in other vehicles... they dim when the lights turn on.
Mine never disappear totally so I don't know if I've been much help.
As the other fellow said, give the dash a gentle thump on the underside, just beyond the ignition switch. The unit that powers the lower right digital cluster is a small hard-drive shaped/sized box that is mounted just inside the panel there. There is a plugin-connector and after all these years the solder has gotten tired on these cars. If the cluster momentarily comes on or flickers, chances are very high you have the routine loose connection problem.
Mine was acting up, getting dim, going away, etc before it finally went out alltogether. I pulled the unit out, dropped fresh solder onto the backs of the connector pins and BAM it works perfectly now.
One of the more satisfying fixes I've done since it was free, didn't take long and seems to be a permanent solution.
thats why I got rid of the **** foo foo digi sh*t and swapped it with analog.
and by the way, don't ever take advice from anyone that is trying to help you with "try to hit the dash" to get something to work
yah that could lead to more possible future problems ..
resolderin the connections on the gauge cluster wont be the fix the problem with tha z31 is the module uner the right hand side of the dash that controls the whole digi dash.. problem is that over the years moisture gets in from the a/c vent thats right by it ( so i have heard) and the soldering connections come loose so all you have to do is take that apart and resolder the connections and it should be good to go i know many people that have done this to their z31 and fixed the probem..
unfortuneately i have this same problem but im swapping in the analog cluster cause the digi is so **** hard to see when the sun hits it ...