New bulbs but lights still dim
Thread Starter
AudiWorld Newcomer
Joined: Mar 2012
Posts: 3
Likes: 0
New bulbs but lights still dim
Hi All,
New member, but have previously browsed and found wghat I needed!
I noticed recently that my headlights were dangerously dim (dipped beam especially) so I bought some new bulbs (extra bright but not illegal) on changing the bulbs, the light does appear brigher, but still gets 'drowned out' by cars coming the opther way!
I did wonder whether the battery might be to blame, so I connected the battery from our other car to mine (as if jump starting) which had no effect.
The dipped bulbs are behind a focusing lens, which still seems fairly clear so I doubt that this is the problem...
Does anyone have any advice what I should try next?
Thanks!
New member, but have previously browsed and found wghat I needed!
I noticed recently that my headlights were dangerously dim (dipped beam especially) so I bought some new bulbs (extra bright but not illegal) on changing the bulbs, the light does appear brigher, but still gets 'drowned out' by cars coming the opther way!
I did wonder whether the battery might be to blame, so I connected the battery from our other car to mine (as if jump starting) which had no effect.
The dipped bulbs are behind a focusing lens, which still seems fairly clear so I doubt that this is the problem...
Does anyone have any advice what I should try next?
Thanks!
Tech Guru
Joined: Oct 2002
Posts: 8,010
Likes: 192
From: Olney, MD
Old reflectors...sometimes the shiny isn't.
The other problem isn't necessarily your battery....hooking up another battery in parallel to yours isn't going to affect the voltage/current delivered to your bulbs.
Historically, the wiring to OEM halogen bulbs is barely adequate to deliver full voltage at operating current draw to those bulbs. The current has to go from the battery through the headlight switch (and all the wiring between) and then to the headlights...there may be a relay or two between but the wiring from the battery to the relay and the relay to the light is often too small. V=IR, or what happens is the resistance in the wire times the current draw generates a voltage drop across the wire, thereby limiting the voltage delivered to the bulb.
Further, the lowered voltage causes the bulb to draw MORE current (the bulb is rated at 55 watts, lower voltage means more current for the most part, other factors will come into play but I digress) which means more voltage drop in the line. Bulb brightness/output is related to voltage.
Sooo, you might look at (1) the reflectors...are they dull, dirty, etc. Often the reflectors can't be polished without removing the micron-thin coating, they don't use metal anymore, it's a vapor deposit on plastic, and
(2) Check the voltage to the bulb AT the bulb with the bulb lit. If it's lower than 13.8v or more than .3-.4v less than battery voltage, you need to wire in relays and heavier wire.
The other problem isn't necessarily your battery....hooking up another battery in parallel to yours isn't going to affect the voltage/current delivered to your bulbs.
Historically, the wiring to OEM halogen bulbs is barely adequate to deliver full voltage at operating current draw to those bulbs. The current has to go from the battery through the headlight switch (and all the wiring between) and then to the headlights...there may be a relay or two between but the wiring from the battery to the relay and the relay to the light is often too small. V=IR, or what happens is the resistance in the wire times the current draw generates a voltage drop across the wire, thereby limiting the voltage delivered to the bulb.
Further, the lowered voltage causes the bulb to draw MORE current (the bulb is rated at 55 watts, lower voltage means more current for the most part, other factors will come into play but I digress) which means more voltage drop in the line. Bulb brightness/output is related to voltage.
Sooo, you might look at (1) the reflectors...are they dull, dirty, etc. Often the reflectors can't be polished without removing the micron-thin coating, they don't use metal anymore, it's a vapor deposit on plastic, and
(2) Check the voltage to the bulb AT the bulb with the bulb lit. If it's lower than 13.8v or more than .3-.4v less than battery voltage, you need to wire in relays and heavier wire.
Thread Starter
AudiWorld Newcomer
Joined: Mar 2012
Posts: 3
Likes: 0
Thanks! Gives me somewhere to start!
Old reflectors...sometimes the shiny isn't.
The other problem isn't necessarily your battery....hooking up another battery in parallel to yours isn't going to affect the voltage/current delivered to your bulbs.
Historically, the wiring to OEM halogen bulbs is barely adequate to deliver full voltage at operating current draw to those bulbs. The current has to go from the battery through the headlight switch (and all the wiring between) and then to the headlights...there may be a relay or two between but the wiring from the battery to the relay and the relay to the light is often too small. V=IR, or what happens is the resistance in the wire times the current draw generates a voltage drop across the wire, thereby limiting the voltage delivered to the bulb.
Further, the lowered voltage causes the bulb to draw MORE current (the bulb is rated at 55 watts, lower voltage means more current for the most part, other factors will come into play but I digress) which means more voltage drop in the line. Bulb brightness/output is related to voltage.
Sooo, you might look at (1) the reflectors...are they dull, dirty, etc. Often the reflectors can't be polished without removing the micron-thin coating, they don't use metal anymore, it's a vapor deposit on plastic, and
(2) Check the voltage to the bulb AT the bulb with the bulb lit. If it's lower than 13.8v or more than .3-.4v less than battery voltage, you need to wire in relays and heavier wire.
The other problem isn't necessarily your battery....hooking up another battery in parallel to yours isn't going to affect the voltage/current delivered to your bulbs.
Historically, the wiring to OEM halogen bulbs is barely adequate to deliver full voltage at operating current draw to those bulbs. The current has to go from the battery through the headlight switch (and all the wiring between) and then to the headlights...there may be a relay or two between but the wiring from the battery to the relay and the relay to the light is often too small. V=IR, or what happens is the resistance in the wire times the current draw generates a voltage drop across the wire, thereby limiting the voltage delivered to the bulb.
Further, the lowered voltage causes the bulb to draw MORE current (the bulb is rated at 55 watts, lower voltage means more current for the most part, other factors will come into play but I digress) which means more voltage drop in the line. Bulb brightness/output is related to voltage.
Sooo, you might look at (1) the reflectors...are they dull, dirty, etc. Often the reflectors can't be polished without removing the micron-thin coating, they don't use metal anymore, it's a vapor deposit on plastic, and
(2) Check the voltage to the bulb AT the bulb with the bulb lit. If it's lower than 13.8v or more than .3-.4v less than battery voltage, you need to wire in relays and heavier wire.
Trending Topics
AudiWorld Stories
Bringing Audi to Life for Audi Fans
10 Strangest Audi Designs That Actually Made Production
Joe Kucinski
2027 Audi Q7 and SQ7: Audi Upgraded EVERYTHING!
Michael S. Palmer
Audi Unveils Absurdly Cool New Supercar: 10 Things You Need to Know!
Verdad Gallardo
The Highs & Lows of Every Audi C-Class Generation
Joe Kucinski
Top 10 Most Expensive Audis Ever Sold on Bring-A-Trailer
Brett Foote
10 Audi Features & Options We Miss the Most!
Joe Kucinski
Audi Recreates Crazy-Looking Speed Record Breaker From 1935
Verdad Gallardo
Coachbuilder Recreates the 1995 Audi TTS Concept
Verdad Gallardo
Every Audi V10 Car Ranked!
Joe Kucinski
Thread
Thread Starter
Forum
Replies
Last Post
|everso!|
TT (Mk1) Discussion
28
Mar 8, 2008 07:06 AM
A4wheelin
A4 (B6 Platform) Discussion
2
Jan 25, 2004 01:46 PM
Sarasota1.8T
A4 (B5 Platform) Discussion
6
Dec 13, 2003 10:53 AM
rap413
A4 (B5 Platform) Discussion
3
Jan 22, 2001 10:41 PM
