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View Full Version : S13 HOW TO: Fix for dash lights not working (fried TCU)


Magoo1222
02-11-2019, 11:02 AM
The other day, the dash lights randomly stopped working in my s13 (gauge cluster, dash buttons, HVAC, the whole shebang). After checking the fuses and confirming that power was getting to the bulbs, I did a bit of research and concluded that the problem was with the Timing Control Unit (the little white box located next to the fuse box, behind the driver side kick panel). While this is a known problem, I could not find any good documentation on the repair, so here you go.

Step 1)
Remove the driver side door sill plate and driver side kick panel to expose the TCU
http://i65.tinypic.com/2enuet3.jpg

Step 2)
Open the unit by pushing in the 4 plastic tabs with a screwdriver and slide the circuit board out of the case (be gentle when prying, the plastic is old and brittle, I ended up breaking one of the tabs in the process).
http://i65.tinypic.com/auhzqc.jpg

Step 3)
At this point, it will likely be obvious if the TCU is indeed your culprit, as the inside of the case will smell horrid (burned circuitry). Take a close look at the board for any obvious burned components and traces. In my case, this large trace on the end of the board was completely fried.
http://i65.tinypic.com/1z313k0.jpg

Step 4)
Using solder wick or a solder sucker, remove the old solder at each end of the trace, as well as any pieces of the copper trace left intact. Then clean the burned residue with rubbing alcohol in preparation for the repair.

Step 5)
Using a light gauge wire (I used 18 gauge as it is what I had handy, it doesn't need to be anywhere near this heavy gauge, but it will do), bridge the pins that used to be connected via the trace.
http://i66.tinypic.com/1vw3o.jpg

Step 6)
Reassemble the board into the case and reinstall into the car. Enjoy your functional dash lights once more! :2f2f:
http://i66.tinypic.com/2n6dvmp.jpg