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?
Dim Headlights
- Thread starter Stumpy
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Find out where the ground is and make sure that it's clean and tight.
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!
Screw theory....Put it to the test!
![[Linked Image from i.imgur.com]](https://i.imgur.com/sypakzh.png "[Linked Image from i.imgur.com]")
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.
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
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
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.
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.
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.
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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