Illumination not working on cluster

[Fabunoz]

Hello everybody I’m having trouble with my Illumination on cluster working 1992 nsx.when I bought this car I noticed my fuel guage wasn’t working.I ended up swapping a new guage in and it worked only issue was my dimmer switch stopped working (maybe too much force when taking it off).I ended up buying a new one and swapping it out,everything was fine again.4 months later or yesterday I had bought new tail lights as mine were cracked.once swapped tailights and turned on car I noticed the right tailight running lights would not turn on but driver did(only brake and turn signal work).to note when I bought the car I was informed about tailight issue and previous owner spliced from left tailight to right for both of them running lights to turn on.I read on another post to check fuses #38 as can pop and cause that issue.I ended up putting new 15 amp in #38 and #39 in hood fuse box.I also removed tailight relay to inspect.once I put everything back I turned car on and noticed that the cluster would not light up anymore and dimmer switch was not working.so I’m asking did removing fuse and swapping them maybe fry the dimmer switch or what could have caused it to stop working?it was a brand new switch about 4 months in car.also swapping out fuse did not fix the right tailight issue will have to splice how previous owner did.let me know what you guy think about the issue

 

[Old Guy]

Fuse #38 supplies the instrument cluster lights and a whole bunch of other lights on the dash as well as the license plate lights and side marker lights as well as the right side tail lights (nothing to do with the brake lights or turn signals). Fiddling with fuse #38 may have disturbed something.

I noticed the right tailight running lights would not turn on but driver did(only brake and turn signal work).to note when I bought the car I was informed about tailight issue and previous owner spliced from left tailight to right for both of them running lights to turn on

Here is the wiring diagram for the tail light circuits







If the right tail lights are dead, then something happened such as a broken wire or loose connection in the supply between the load side of the #38 fuse and the connection at the tail lights. Splicing a supply from the left tail light to the right tail light was just a bodge to make the right tail light illuminate, not a repair.

On the last diagram, look at all the stuff supplied from the #38 fuse starting at the top of the diagram. What works and what doesn't work? If the left front parking light does not work then you know that the problem is some place close to the the start of the #38 circuit. The fact that your dimmer control and gauge lights are dead suggests that the failed connection is somewhere before the C450 junction connector. Finding out what does and doesn't work may help you isolate the location of the failure. As an observation, if the failure occurred after you fiddled with the #38 fuse you might want to examine the wiring at the #38 fuse holder (which means removing the fuse box) to see if it is damaged and whether fiddling with the fuse just made the damage permanent.

You might want to check out this thread for relevant information

LOST MY LIGHTS

30 year owner of 92 w/25k miles that runs great, but have a likely self imposed lighting mess. About a year ago I crossed the subwoofer power leads.(with the key and radio on!) and blew the stereo which also blew the ignition switch and around that time lost right taillight, left turn signal...

www.nsxprime.com

 

[Fabunoz]

Thanks for the diagram and info appreciate it .I chased down red/black wire best as I could but didn’t see any thing wrong with wires in harness.I ended up just splicing right tailight into left for now to give power.weird thing I noticed my glovebox light wasn’t working but once I spliced tailights it was working.I also unplugged the dimmer switch and replugged and now the cluster lights/dimmer switch are working again.definitely something wrong with the wiring somewhere but will leave it like this for now until I can bring car to trustworthy auto electrical shop

 

[Old Guy]

If your glove box light started operating again when you spliced the left and right tail lights together, take a look at that diagram in post #2. Your problem is probably somewhere between connector C450 and the load side of fuse #38.

Have you checked to see if your left and right front parking lights are working which are also on the fuse #38 circuit and whether they were affected by your splice? The wiring for the front parking lights is not exactly as shown in the diagrams. If you have a failure at the front parking lights it can screw up the complete fuse #38 circuit. Read that thread that I attached about user Tanto's self induced fuse #38 agony associated with the front parking lights. Check things thoroughly because you do not want to go removing the dash to access all the points on the fuse #38 circuit.

 

[Fabunoz]

Thanks for the help that solves it then .didn’t know the running lights were tied into it and could cause all these electronics not to work!my running lights are actually not working ,I’m guessing this nsx was converted to newer gen headlights at one point and wires were cut…there’s the problem maybe I can source some Honda wires and connectors from junkyard and wire to what’s left of existing harness.better than buying a full harness I think

 

[Old Guy]

Another victim of home wiring creativity.