Back Lighting Dim in and out when idealing
09-10-2015, 02:49 PM
#1
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Mercedes 2002 clk 430 CV
Back Lighting Dim in and out when idealing
What could cause the back lighting to dim in and out when I turn on the lights or when the car is at a stand still..slow dim in and out even behind the AC indicator?
09-10-2015, 08:06 PM
#2
MBWorld Fanatic!
When the lights get brighter because a car is moving (the engine is moving faster), it is commonly a sign that the battery is not adequately retaining a charge.
09-10-2015, 10:33 PM
#3
Senior Member
I'd look to the alternator first. Check voltage at the battery when the engine is idling. It should be at least 14.1 volts. If it is less than that, your alternator is not working.
09-12-2015, 04:12 PM
#4
MBWorld Fanatic!
Since you have a W208, this will be easy. Put the HVAC in diagnostic mode and check #24. Is it dropping low at lights? If so,how old is the battery? This is assuming you don't have a booming stereo WITHOUT a capacitor. If you have no idea how to put the HVAC in diagnostic mode, here's a link - www.fitzhughmedia.com/MBF/acdiag.html
You don't have to go for a 20 minute drive to check voltage, that's only for Freon pressure.
You don't have to go for a 20 minute drive to check voltage, that's only for Freon pressure.
Last edited by MarcusF; 09-12-2015 at 04:15 PM.
