Keep blowing gauge clusters … 97 940

[Jamesmoore]

So about a month ago, all my gauge cluster backlights went out, along with all the switch pannel backlights. All the instruments and dials still work, warning lights all still work ect just no backlights. All the bulbs were fine. Fuses good and changed the dimmer switch to no avail.

I installed my spare cluster about a week ago, and I got all my backlights back ! Yay, so I know the car side is at least functional, bulbs all good, fuses good, dimmer good.

However today whilst driving, I lost all backlights again … I rechecked the basics again and everything checks out.

It seems that I keep “blowing” the cluster in some way.

I’ve no idea where to start with this, it’s obviously something internal in the cluster that the car is causing damage too from too high current or something.

Any advice ?

 

[mertz]

The dimming is done inside the metal box that's mounted on the rear. I repaired one of these a few years ago and it was either the feed to the box was broken or I jumped 2 wires inside the unit to make the backlights stay on 100% of the time. The box itself manages some of the dimming aspect iirc.