4 people reported this problem
false temp gauge reading or electrical problem - check engine grounds on Hyundai Sonata
I had my car to many mechanics and replaced many parts when my temp gauge kept reading hot, but it actually wasn't. A master tech finally listened to me and went directly to the problem. The manufacturer had not installed one of my ground wires to the engine. That explains why I kept going through batteries and headlight bulbs. Finally the issue got to my temp gauge and my window motor. Not having that ground, my car was handling it in other ways all these years. Of course Hyandai wouldn't reimburse my expenses.
2005 Hyundai Sonata 60,000 mi, Visitor
when I drive my car in mountains road especially in the night,head lights on. the temp.gauge continues to rise up but actually the the engine actual temp. is in the normal range.
2005 Hyundai Sonata 93,000 mi, Visitor
Change of head light bulbs, several batteries, temp gauge rising during idle at stoplights, winter & summer