Gage Cluster quit working

[erxie720]

1984 nissan 4X4 720 PU. I lost all gages and turn signals. Have 12v to both sides of the fuse block. Volt regulator points cleaned. Does the speedometer gage cluster have an internal Fuse? What function does the single red wire that comes out of the bottom of the speedometer housing? would appreciate any help on this!

[PEZi]

I'm assuming this all happened at once? Does the backlighting still work, or did that quit, as well? I'm trying to brainstorm what would have caused this and right now I'm leaning toward something in the wiring harness that runs to the back of the cluster. From everything I can tell, the red wire you're talking about supplies power to the lighting unit which would of course supply the backlighting when your lights are on at night. The rest of the unit is supplied by the clip the plugs in the back. When my gauges started going out, it was one at a time. First the tach went... then the water temp. Etc... In all honesty, I never did figure out what was wrong with mine. Instead I replaced with aftermarket.

You did mention you lost all gauges, though. That does surprise me a little in this situation as the speedo is tied directly to the transmission and has no tie to the electronics, at all. Did you lose the speedo?

Any other info you have would be great...

[AZhitman]

I can't recall off the top of my head, but did the 720 have that voltage regulator box on the back like the earlier Datsuns? If so, that thing is the culprit more often than not.

Let's check the FSM and see what it says: www.datsunservicemanual.com I'll check back in when I've had some rest.

[erxie720]

I'm assuming this all happened at once? Does the backlighting still work, or did that quit, as well? I'm trying to brainstorm what would have caused this and right now I'm leaning toward something in the wiring harness that runs to the back of the cluster. From everything I can tell, the red wire you're talking about supplies power to the lighting unit which would of course supply the backlighting when your lights are on at night. The rest of the unit is supplied by the clip the plugs in the back. When my gauges started going out, it was one at a time. First the tach went... then the water temp. Etc... In all honesty, I never did figure out what was wrong with mine. Instead I replaced with aftermarket.

You did mention you lost all gauges, though. That does surprise me a little in this situation as the speedo is tied directly to the transmission and has no tie to the electronics, at all. Did you lose the speedo?

Any other info you have would be great...

No, the Speedometer does work but every other gage plus the turn signals didn't. Today I was checking wires coming off the hot side of the battery, the fuse box and messing with the ignition switch and low and behold all the gages work including the turn signals. Now, thats unsettling. I'm thinking of changing out the igniotion switch ( not sure if I need the entire lock, key cylinder, switch or just the US119 switch? The back lighting didn't work but does now!

[AZhitman]

Sweet!

I'd recommend replacing the entire switch assembly. It's always nice to have a fresh new key and cylinder!

http://www.nissanpartszone.com/parts/ni ... 01b00.html