Dennis Haynes' post hit upon the likely cause of the higher temperature reading when the headlights are on. It's called voltage drop, in that the headlights take enough power to run that the resistance of the wiring between the battery and the instrument panel causes the panel's voltage to be less than when the lights are off. This in turn causes the guage to read differently when the lights are on. Two ways to test this theory and find out exactly what is going on are to measure the temperature of the engine with lights on/off, with no other conditions changing, and compare the voltage at the guage, as measured with a high-quality meter, with lights on/off. Also, if the temp guage changes reading instantly when lights are switched on, this semi-proves the voltage theory, since the water temp can't change that quickly. Ron Antaki ex-electronics tech now wrecking computers for fun and prophet...
-----Original Message----- From: Vanagon Mailing List [mailto:vanagon@GERRY.VANAGON.COM]On Behalf Of John Baker Sent: Friday, September 07, 2001 9:00 AM To: vanagon@GERRY.VANAGON.COM Subject: Is there any way...
Howdy All, This sounds stupid even as I type it, but Is there any way that driving my 83 water cooled Vanagon with the headlights ON, would affect the water temp gauge reading?? Stupid, right? But I swear i have noticed that when I drive with headlights on, even if the outside temp is a little cooler, my temp gauge reads higher! I have noticed this at night and in heavy fog when i have had lights on. Can outside humidity also affect this reading. Is it possible the head light wiring is arcing with the temp sender wire or something, Or is it JUST A COINCIDENCE!?!?! PS, It's OK if you laugh at me for asking this question ;-)
Peace, JB '66 Split Window Camper '83 H20 Vanagon "You cannot simultaneously work for peace and prepare for war..." |
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