I have a ’96 Nissan Pathfinder and my gauge cluster has started to go on the blink. It’ll randomly cut in and out while I’m driving, with the gauges going from proper operation to flat needles and no light. I’ve checked all the fuses, but everything looks okay. Have any ideas?
A That’s not a defect; it’s a feature – interior strobe lighting! Seriously, though, if the fuses are fine, there are two paths to investigate and neither is much fun. This kind of thing can usually be narrowed down to a corroded earth wire or a bad connection between the gauge cluster and the main wiring harness. Clusters generally consist of one large circuit board with stepper motors to turn the dials, light bulbs or LEDs to brighten the instruments, and microcontrollers to make it all work. Everything is driven through inbound wires attached via plastic connectors.
Your Pathfinder has three of these connectors on the back of the cluster, and one of them may have gone finicky. If you’re going to fix it yourself, you need to be brave: the driver-side dash will have to come apart. Take your time and figure out how the unit was assembled; everything in a dash is built from the inside out, which means the last part on will be the first off.
Start with the trim and look for the bolts and screws that hold the structure together, slowly removing each piece while keeping track of all those nuts and bolts and snapping pictures as you go. Always consult a vehicle service manual, too.
Eventually you’ll be able to pull the cluster away from the instrument panel and view its hindquarters. Inspect the connections for signs of corrosion, which you can clean with solvent, and for breakage. If you don’t see anything wrong, you’re in for an arduous journey, tracing all the wires through the skeleton of the dashboard.
What you’re looking for is a wire routed against the metal support structure. Over time the vibrations from the road may have worn a hole in the insulation of one such wire. As you drive, the exposed copper is earthing to the chassis, making the gauges do their little on/off dance. If that’s not the case, you’re looking at having to replace the cluster. This is not difficult, but it’s usually quite expensive because the odometer has to be synced by a dealer.