1993 Nissan 240SX digital Speedometer/dash not lighting up

1993 NISSAN 240SX
180,000 MILES • 4 CYL • 2WD • AUTOMATIC
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JUANFARIASC
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my digital speedometer doesn't light up(work) all the time. when it doesn't work the whole dash light also doesn't work but if when the speedometer works the dash light is also working. i was told it could be something inside the dash and is easy fixed that is causing the problem and not the speed sensor but what is causing it then?
May 16, 2009 at 7:19 PM
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KHLOW2008
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Hi juanfariasc,

Thank you for the donation.

Being an intermittent problem, the most likely cause would be a loose wire connection or a bad soldered joint of the printed circuit board.

Source should be from the meter cluster and you would have to remove it to check wire connectors, holding screws and solders.
May 17, 2009 at 9:43 AM
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JUANFARIASC
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one thing i forgot to say was that when i turn on the head lights the digital clock back light turns off while the dash light dont turn on.
May 17, 2009 at 7:38 PM
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KHLOW2008
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The data available to me are only for analog meter clusters so I am not able to provide much information for the meter clusters.

You would have to remove the meter cluster to test the lighting circuits. Ic ouldd be due to a bad connector or power from the lighting system is not getting the meter cluster.
Another possibility would be the ground circuit for the meter cluster is faulty.

If the clock lights do not function when speedometer and meter back lights are working, then it could be a separate problem, the bulb could be blown.
May 18, 2009 at 10:05 AM
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JUANFARIASC
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what about the TCU (timing control unit)-someone on line told me its the tcu because that was wrong with his-how would i be able to find out if my tcu is working?
May 20, 2009 at 7:04 PM
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KHLOW2008
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Sorry for the drelay in replying. I have been encountering difficulties logging into my database for the past few days and is still facing it. However it must be noted that the speedometer not working could be due to the Power Control Module (PCM) but the back lights are a different problem as they are not controlled by the PCM. There are 2 separate schematics and one of it has the control unit in the meter cluster. For both, youneed to test oif the speed sensor is pulsing to provide the signal.


https://www.2carpros.com/forum/automotive_pictures/192750_InstrumentWHeadUp93Nissan240SXE01b_1.jpg


https://www.2carpros.com/forum/automotive_pictures/192750_InstrumentWHeadUp93Nissan240SXE01a_1.jpg


https://www.2carpros.com/forum/automotive_pictures/192750_Instrument93Nissan240SXE01a_1.jpg


https://www.2carpros.com/forum/automotive_pictures/192750_Instrument93Nissan240SXE01b_1.jpg

May 22, 2009 at 8:14 AM
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JUANFARIASC
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its the capacitor on the digital speedometer looks like a small can.
May 23, 2009 at 3:27 PM
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KHLOW2008
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Thank you for the input.

It is much appreciated.

There are so many possiblilties for malfunctions and such repairs are not in the book as the manufacturer does not provide repairs procedures for components and recommendations are to replace the meter assy if it is the cause.

When capacitors goes bad, it usually provides some visual clues. Look out for chemical leaks which would show as some oily stuff and it might cause some corrocsion/oxidation of the contacts around it.

From the link, the explanation is very good. Since you are at it, you should look at other capacitors as well. They tend to go bad over the years.
May 23, 2009 at 6:28 PM