Dim Headlights

Messages
17
Location
AL
Thread starter
My mother in laws 2010 Mazda CX-7 has EXTRAORDINARILY dim high and low beams. They are properly aimed but are dim. This model is particularly infamous for this issue. I had new standard halogen bulbs installed. Same dim coverage. I am talking dangerously dim. You have to drive with the HIGHS on to be safe. They are dim and brown.PLEASE DO NOT SUGGEST SILVERSTARS OR SUCH. Those have been tried by others and they are dim as well which leads many to believe it to be a system issue. One owner in a Mazda forum had a theory/question that was never answered. His theory was that a bad ground in the headlight circuit could cause this issue. Anyone more knowledgeable than I know if that theory could be the cause of this issue?
 
Messages
4,736
Location
Fort Worth, Texas
Go to the wreaking yard & get connectors/pigtails for the headlight bulbs. Apply good Ground & Power to the headlight bulbs to see if brightness/performance improves. Screw theory....Put it to the test!
 

LvR

Messages
86
Location
SA
Originally Posted by clinebarger
Go to the wreaking yard & get connectors/pigtails for the headlight bulbs. Apply good Ground & Power to the headlight bulbs to see if brightness/performance improves. Screw theory....Put it to the test!
approved
 
Messages
65
Location
USA
It's likely that the headlamp is burned on the inside. Take one of these and take a peek inside the low beam projector. The inside should be a smooth, shiny silver. Not wavy, not textured, and definitely not brown/black. [Linked Image from i.imgur.com]
 
Messages
427
Location
Kevil,Ky
Use a volt meter. Get some connection to the bulb and measure voltage to the bulb. Then measure voltage from the bulb to chassis ground. Try un-plugging one bulb and see if the other on gets brighter.
 
Messages
24,107
Location
MA, Mittelfranken.de
Originally Posted by clinebarger
Go to the wreaking yard & get connectors/pigtails for the headlight bulbs. Apply good Ground & Power to the headlight bulbs to see if brightness/performance improves. Screw theory....Put it to the test!
+1 Very common problem on some Euro cars also, there have been TSB's over the years with this solution. Some get so hot they melt the connector for these they make ceramic connectors for some.. https://www.amazon.com/TEMPERATURE-CERAMIC-Headlight-Connector-moisture/dp/B004IA3YQK https://www.amazon.com/Headlight-Ha...d=1586520158&s=automotive&sr=1-4
 
Messages
4,873
Location
NJ
Originally Posted by vwmaniaman
Use a volt meter. Get some connection to the bulb and measure voltage to the bulb. Then measure voltage from the bulb to chassis ground. Try un-plugging one bulb and see if the other on gets brighter.
I agree. Sounds like it's not delivering enough electricity to headlights.
 
Messages
1,437
Location
UT
I would absolutely start with the grounds. Trace the ground, remove the screw, clean the terminal, screw, and body surface where the terminal contacts. Apply a small amount of contact grease, and reassemble. If the ground doesn't take care of the dim bulbs, replace the lamp sockets. Again, apply contact grease when attaching to the lamps. Dim headlights was a common problem on older cars from the '60's and '70's. Rust around the ground was always the cause.
 
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