MN69Grande 203 Report post Posted July 23, 2017 So since I got the new Aluminum radiator and the Contour fans my car runs about 182 on my digital gauge. 70 degree days 182, 80 degree days 182, 90 degrees 182. Pretty good this summer. But I always drive during the day. Tonight I stayed at a friends house a little later and turned the headlights on, on the way home not to see but to be seen. Anyway I look down at the gauge 187. Ok not to hot but higher than usual. Get into my neighborhood and shut the lights off, immediately drops to 178 then 182. So my question is could running the headlights (sealed beam) have caused the car to run 5 degree's hotter. Or is it possible turning them on affected the way the gauge was reading? The wires are no where near each other. Anyway Strange happening wondered if this happens to anyone else. Quote Share this post Link to post Share on other sites
Midlife 814 Report post Posted July 23, 2017 Possibly. Voltage to the constant voltage regulator is via a resistor wire from ACC power at the ignition switch, which gets its voltage from the battery. When headlights are on (power from the battery side), voltage would drop a tad. However, the bimetallic CVR and the resistor wire should isolate battery voltage fluctuations from CVR output. Oh...wait a minute! If you have a digital temperature gauge, it gets its power directly from ACC, so yes, the input voltage to the gauge should drop, which raises the needle a bit. Your fuel gauge should also bump up a bit (free gas!). Next time when driving around during the day, turn on the headlights and see if your gauge is reading a bit higher. 1 69RavenConv reacted to this Quote Share this post Link to post Share on other sites
