Lights dim when braking?
12-09-01, 01:20 PM
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Lights dim when braking?
Hey guys
I just noticed that when i'm at a stop and I press on the brake, my tachometer, speedometer, etc all dims a bit. The car is also charging at 14 v. anyone know what's going on?
I just noticed that when i'm at a stop and I press on the brake, my tachometer, speedometer, etc all dims a bit. The car is also charging at 14 v. anyone know what's going on?
12-09-01, 01:37 PM
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Bad grounding of the electrical system. Run a search on "Grounding", and you will get all yo answers there! 7s are notorious for bad grounding from the alternator, which is probally your problem!
12-10-01, 10:18 AM
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Dimming lights
Even on a perfectly running rex there will be a noticable dimming of the instrument panel lights when you mash on the brake.
A light bulb filament is designed to draw a given amount of current when it is operating and hot. For a nano second or two when current is first applied to it and it is cold the current draw is massive, like several thousand amperes. It is the same type of thing as your house lights dimming for a moment when an appliance like a freezer or air compressor starts up. The brake lights are a high current draw bulb.
Checking for grounding problems and adding a ground wire or two is still a very good idea. All I am trying to get across here is do not go crazy trying to stop the dimming all together. Go to any other type of vehicle and do the same thing. I will bet you the panel lights on that one will dim some too.
A light bulb filament is designed to draw a given amount of current when it is operating and hot. For a nano second or two when current is first applied to it and it is cold the current draw is massive, like several thousand amperes. It is the same type of thing as your house lights dimming for a moment when an appliance like a freezer or air compressor starts up. The brake lights are a high current draw bulb.
Checking for grounding problems and adding a ground wire or two is still a very good idea. All I am trying to get across here is do not go crazy trying to stop the dimming all together. Go to any other type of vehicle and do the same thing. I will bet you the panel lights on that one will dim some too.
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