Adding LED dash lights to the XJ
I recently swapped in a used cluster to replace mine where the odometer had stopped working. The bulbs in it were pretty dim. I decided to try using LED bulbs.
i bought these from Amazon:
The listing gave me a a warning that these would not fit my 1991 Cherokee. But since the measurements were correct I gave it a chance. They turned out to be the right bulbs.
The trouble with the LED bulbs is that they are polarized while the originals don’t care how they are installed. Also, the LED bulbs were not marked for + and – that I saw. So I rigged up a test set up using my 12V jump box and some alligator clips.
Now you can trace each of the copper traces on the board and see what is positive and negative, but I decided to just use trial and error. That technique got me through engineering school it can get me through five LED bulbs.
I hooked up a lead to the ground that is handily marked on the board. I touched the positive lead to the solder joint that powers the lights to test each one. See the photo:
To make sure the bulb lit up, I removed the one next to it and peeked inside:
If it did not light up, I just turned it around. It did not take long to get all five in the right way around.
Once the cluster was back in the Jeep I am happy with the way it looks. I also took some time to clean it all up while it was out.
