Digital Dash/ H.U.D. Problems

[A_Rivers]

I have a 1991 240SX with 190,XXX Miles on it, just recently since it got cold the speedometer will not come on right after I start the car, every other gauge works. If I park the car inside at work and start it the speedometer comes on without any problems, it's only when its cold that it acts up. Also if I turn my lights on while the speedometer is not working none of the gauge illumination works. Is there a relay that controls this function that could be going bad and if so where might I find it at? I am a mobile electronics installer for a dealership so I am pretty proficient when it comes to this stuff, but this one has me stumped.

I did search but only found a handfull of threads on this and none of them were exactly like mine and the culprit it seemed was a solder joint problem which I will look for on my car. But I wanted to get some other avenues to try aswell.

[aaronsnocker1]

try the faq on 240sx.org. They seem to have it pretty well covered there. I have the same problem and I have pretty much given up on it. I just tell how fast I am going by the rpms. By the way does your car ever just cut out sort of like a speed govenor?? just wondering if the two are related.

[NISTECH]

yes the 2 would be related since the speedo head is the speed sensor for the ecm. go after the soilder joint problems. in both the head and the control unit.