XG300 Heater Blower Stays ON

Either the "high blower relay" or "power transistor" is shorted. In most cases, the problem is the power transistor.

At the bottom of the schematic, click on the "component location index" link and then click on the name of the component you want to see. It'll bring up a nice picture of the location. I only looked at the list quickly and didn't see a link for the power transistor. It's located where the blower relay would normally be located on a vehicle with manual controls. Click on the "blower resistor" link to see the picture for the power transistor.

Thanks again Hyundaitech, This is the 3rd electrical issue I've had come up on this XG this year -about 65,000 mi. (103,000km) on it . Given where we live -middle of nowhere- seriously to get to a dealer that knows anything about this vehicle, I've got at least a 6 hour drive through high mountain passes that may or may not be open due to our Winter conditions here in the Interior of British Columbia. Usually that means a minimum of one overnight at a motel, if I'm lucky. Now let me tell you the auto repair is cheap relative to the shopping my wife will do in the Mall while we wait for the car to be fixed. That's why I try to repair it out in the SNOW, so thanks again for all your help. But I have to say my 1990 beat-up old Ford F250 with rust holes in the floor for the melted snow to drain out, looks better & better to me. And the heater works just fine! The only thing a bit 'cranky' is the driver.

BCinBC PS: Had all these funny shiny wet spots about 2" circles/ ellipses behind a rear wheel the other morning. Took a bit of detective work, but the snow tracks told the story. Seems deer must have been licking the dried salt (from the slippery roads) off the lower rear fender!