false temp gauge reading or electrical problem - check engine grounds on Hyundai Sonata

Problem Description

(14 people reported this problem)

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$88 - $111: General Diagnosis
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Viewing 1-5 of 5 comments
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.

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.

Change of head light bulbs, several batteries, temp gauge rising during idle at stoplights, winter & summer

Cleaned ground wire to keep it from running hot with ac on in slow traffic.

First told that it was my radiator, problem remained, went to the dealer, they said I never needed a new radiator that the problem was my thermostat, replaced that and at $1,000 later, the problem still exists. The gauge can go nearly to the H mark and nothing is smoking, no smell, not hot engine... then it can drop down, and just change whenever it feels like it. It's frustrating. The dealer says that it's normal for the gauge to go above the half way mark on hot days, but one, it never did this before, two, even when it's not hot, it does this... any thoughts?