73 620 Headlight trouble

[dezertranger]

I recently got my 73 620 running. All my lights were working two days ago, yesterday I went to go cruise around the block and neither my headlights or highbeems will come on. The parking lights on the lower valence however do turn on when I pull the knob out? All the fuses look good and all the wires are connected in the back of the headlights? Any ideas??

[banzai510(hainz)]

clean the fuse box area ands reseat the plug on the fuse box and light relay

[Eagle_Adam]

that ^^^

 

two screws hold the fuse box on, pull the battery first then remove the screws. There are two wiring harness ends that attach to the box, detach them and clean the box with vinegar.

[ggzilla]

Or do a voltage drop measurement at the fuse box to see if that is really the problem. Test or do the work, your choice.

[datzenmike]

Never Never Never trust a fuse on looks alone. Place a quarter across the fuse contacts... if the lights come on the fuse or the contacts are bad.

[ggzilla]

Or do a voltage drop test. Never rely on looks alone.

[datzenmike]

The quarter is cheaper. :lol:

[dezertranger]

I wiggled the fuse and they popped on..I know the fuse box has seen better days. What would be your suggestions?

[ggzilla]

our recommendation is:

two screws hold the fuse box on, pull the battery first then remove the screws. There are two wiring harness ends that attach to the box, detach them and clean the box with vinegar.

 

Here are some more detailed instructions: Fuse Box Cleaning

[dezertranger]

What I mean is the fuse box is pretty dry rotted, I'm afraid if I mess with it too much it's gonna start disintegrating. As I was messing with the fuses it made some crumbling plastic sounds lol

[Pacific coast Datsun]

I replaced the fuse block in ky 74 620 for that very reason. Its aftermarket..i believe i bought it at Auto zone.

[dezertranger]

Looks like I'll be makin a trip to vato zone tomorrow, Thanks!

[moparvwfreak]

i have a box out of a 78 620 in my 73. works great and the lights go out with the ignition. love that setup. also RELAY the system! it helps keep the fusebox from melting with prolonged light usage as it takes the heavy load off the circuit.

[dezertranger]

Funny...I just pulled a block off a 78 yesterday, looks to be in great condition, just gonna clean it up a bit and then swap em out...probably a dumb question but does it matter what motor was in the truck, mine is the L16 and the block came from a truck with an L20

[datzenmike]

Nope, the 620 had L16, L18 and L20Bs in them and pretty much the same output alternators.

[dezertranger]

Perfect, thank you