Diagnose and fix Kia speedometer doesn’t work
If you’ve run into a problem where your Kia speedometer doesn’t work, the dash brake light stays on, or the tachometer doesn’t work, this may be the fix you’re looking for.
One of the rules of electrical diagnosis is that power always has to return to ground and if it can’t find ground at the expected spot, it will find ground through another component, even if it has to flow backwards through a light bulb.
In the case of a Kia speedometer doesn’t work situation, the ground wire for the speedometer and tachometer is located below the center of the instrument cluster. If it’s loose or corroded, the power will seek ground at another spot. Specifically, if you pull up on the emergency brake lever, it turns on the emergency brake light and at that point, it will ground through the brake light bulb.
The fix is to clean and tighten the ground strap under the instrument cluster.
The best diagnostic procedure in a case like this is to pull up the power and ground diagrams for the items that are inoperative, and find the common ground points. Most DIYers think that the problems occurs on the power side. It can, but it’s rare. Faulty ground are FAR more common. So ALWAYS start by checking ground connections, especially when the operation is intermittent or makes no sense.
©, 2016 Rick MuscoplatPosted on by Rick Muscoplat