I have a broken speedometer on my 78 620 and was wondering if anyone either knows how to fix it, where a replacement might be obtained, and if speedometers from other Datsuns would work if I can't find one from a 620. I just bought the truck and the previous owner said he had just replaced the speedo cable and it still won't work.

coleeluke wrote:I have a broken speedometer on my 78 620 and was wondering if anyone either knows how to fix it, where a replacement might be obtained, and if speedometers from other Datsuns would work if I can't find one from a 620. I just bought the truck and the previous owner said he had just replaced the speedo cable and it still won't work.

I get mine for like 7.99 at autozone. Use the original key thingy that slips into your tranny and cut the new cable to length. You will have to uncrimp the part the goes into your tranny and pull out the old cable...takes a little effort, but then you carefully re crimp it onto the new cable. I got mine working that way.

Welcome to the forum BTW

Speedo on mine is also out. Ordered a while new cable from rock auto, hopefully it fixes the problem. I also have no dash backlight at night, what could be the problem?

i'm not too accustomed to 620 wiring... but for the dash backlight check the fuses and does it have fusible links? if so there may be a short somewhere or something

my dash backlight was also out.my problem was my light switch was worn out and turned faulty.just pull out the switch and clean the connections. And my speedometer doesn't work either.i have a black top s13 srand idk where to start to fix the problem