Instrument Cluster Lighting Dark

here is the symptoms so far for my 1993 audi 90 cs vin WAUBK58C7PA257821. my instrument cluster including the backlighting for the fan, temp, and airflow knobs, defrost and fog buttons are all
dead and dark. however, the lights for the dummy lights all work (i.e. if i turn my brights on the blue light lights up on the dash.) also, the license plate lights (both of them) do not work. i replaced those bulbs thinking they wree burned out and they still do not light up. are these two problems related? thanks! -jason
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
They might be related if the wiring in the '93 resembles the T44 series. In that series it was typical to have the wires break where they enter the trunk hinge which caused many problems including license lights and dash lights. I have no idea if the '93 has the same issues.
snipped-for-privacy@gmail.com wrote:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
Jason, The dash lights in the Type 44's (100/200/5000/V8) are affected by the condition of the license plate lights, so I would say that chances are that the 90 is the same. Check for voltage at the license plate light sockets - if there's none, or intermittent, check the wiring harness where it flexes - chances are you have some broken wires there that need splicing. Make sure that the license plate light bulbs are the correct wattage too, I had one that was a higher (or lower, not sure) wattage and you could see it glowing faintly when the car was running but the lights were off. Another thing that I did that seemed to have a good result was to replace all of the burned out light bulbs in the instrument cluster - you'd be surprised how many can go and you can still see the gauges. The Instrument Light booster is controlled by the dimmer switch, I guess when there is a change in the resistance or current experienced by the booster, or the circuit feeding the booster (that has the LP lights on as well), then the booster will not send power to the instrument lights. If all this fails, the Type 44 instrument lights are also rendered inoperative by a melting of the light switch stalk - the use of flash-to-pass and the large headlight current passing through simple plastic and metal switches melts the plastic and causes instrument lighting to go. Relaying the headlights to feed power directly from the alternator seems to way to go Cheers! Steve Sears 1987 Audi 5kTQ 1980 Audi 5k 1962 and '64 Auto Union DKW Junior deLuxes (SPAM Blocker NOTE: Remove SHOES to reply)

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
If the lights for the license plate are dead there is a very high probability that this is because the cables are worn out at the hinges on the trunk. Since they are bended every time you open it they tend to wear out. I've had 4 audi-cars and so far I have fixed this issue on all of them. Sometimes the worn cable results in just a dead light in the rear but sometimes it shorts out and results in a burnt fuse. I lost the differential lock and the lights in the climatronic and all buttons in the car plus the lights in the ceiling didn't go out. (Quite annoying when driving at night.).
Check for burnt fuses and if so, consider replacing the cable to the trunk door. The connections for the cable are by the left rear light and then there are connectors in the trunk door. If you have a sedan you can easily replace it yourelf. It takes about 30-60 minutes if you are a little bit handy. If it is a station wagon you're in for a bit more work since there is a longer cable and more parts to remove.
/Stefan
snipped-for-privacy@gmail.com skrev:

Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload
thanks for your help. i'll check the trunk wiring. -jason
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
<%-name%>
Add image file
Upload

Motorsforum.com is a website by car enthusiasts for car enthusiasts. It is not affiliated with any of the car or spare part manufacturers or car dealers discussed here. All logos and trade names are the property of their respective owners.