Datsun Roadster Forum-311s.org

Hey All,

Red 1967.5 must know I've scheduled inspection for tomorrow... going through her today and getting the last items fixed up. and right on cue:

Horn just up and quits. Was working this morning, nothing this afternoon. And at the same time: the headlights stop working.

OK... basics check: battery good. run a jumper battery + to horn, BEEP! Check relay, 12V where it should be... nothing at the horn pad. Pull the combo switch wiring and connect to known good one... no horn. Fine. put the wiring back to the old switch and test: BEEEEPPPPP!!

OK, THAT was weird, but whatever.

Now lights: No headlights, no marker lights, no dash lights, no map light, no reverse light and no brake lights!!!!

HOWEVER! Four way flashers and signal lights work just fine, front and rear.

What
The
Hell?!?!?

Fuses are all good, have not replaced them however.

Running short on time, what should I be checking?

Thanks,

If you are in the Facebook group you might post there as well. A little more volume of folks that will see it. Not necessarily more knowledgeable

Check your various ground wires.
Sounds like one or more came loose or broke off.

viewtopic.php?p=152503&hilit=Ground+locations#p152503

There are also a couple wiring connector harnesses under the dash near the firewall (drivers side) and one coming out of the firewall under hood by the master cylinder that often create electrical gremlin issues that are hard to track down. It’s worth checking that they haven’t come loose as well.

The horn contacts are all neg current side
The brass spade connectors in the multi plugs will get corrosion between. the brass and copper wire , with a bit of acidisity there you have a lite battery action ,which causes electrolysis, I would jump a wire across the multi plug and solder it in on , seal with silicon / tape. if was easy to get the multi plug apart solder wire to brass. But tarnished brass is high resistance
Rig up a 5 amp circuit breaker between the neg batt term.and cable and you can jump wires like crazy to see if that points to your problem

Fuses. It was fuses.

They metered fine on the top, but were corroded in the clips:
Pulled all 4, hit the clips with the De-Ox spray and polished up with a bit of ScotchBrite pad. Installed 4 new fuses and:
Now, onto the road inspection...