Lexus IS Forum banner

1 - 18 of 18 Posts

·
Registered
Joined
·
715 Posts
Discussion Starter #1
so my passenger headlight has been playing games with me. sometimes it will turn on sometimes it wont. So i said screw it and bought new bulbs and as i was replacing them i noticed this box (see pics) was making a funny noise as i was turning the headlights on and when the light decided not to turn on. When they turn on the little box doesnt make a noise at all. does anyone know what this is and or how much it might cost to replace. and also could this be why my headlights are playing with me.


 

·
Super Moderator
Joined
·
19,540 Posts
Everytime you turn on your headlights, the DRL relay(#3/#4) pictured above turns on. This only turns the relay on so if/when you flip your high beams on, they come on at full power. So basically, that's all that relay above does, turns the DRL's to full power highs wether you turn on the highs or not(does not control headlights). Unless that relay's coil is going bad and reducing voltage going to your ballasts, then there is no need to replace it. You can try unplugging both connectors at that relay and give the headlights a try, but I doubt it will have any effect on your headlight problem.

If your new bulbs don't work, then it could be the ballast, bulb socket(look for corrosion), or power feeding the ballast. There's only one headlight relay, so if there is no problems with the one headlight, then it's more likely the ballast or bulb of the new bulb doesn't work properly.

One other thing, relay pictured should always click when the headlights come on, if it doesn't then there is a problem with power feeding the headlight ballasts(because that's where power comes from to turn the relay on). Try your high beams the next time you suspect that the DRL relay doesn't click or when the headlights turn on. Like I said, it's strictly part of the DRL's/high beams only, but a bad coil can reduce power going to one ballast...I'm kinda doubtful there is a problem with that relay though.
 

·
Super Moderator
Joined
·
19,540 Posts
It the relay making a buzzing noise? If so, then it need to be replaced.

The ballasts make a whining noise, which is normal. Perhaps one is bad.
I do agree that the ballasts make a whining noise when turning on/running, but if the relay pictured above was buzzing or not clicking, then he would have problems with his high beams only(or DRL's). Try unplugging it(both connectors), it should have no effect on the headlight not working.

The next step in troubleshooting the headlight is to use a voltmeter(any cheap one will do) and see if you have 12.6-14.8 volts feeding the ballast. If the Op does, and bulbs are new, then it's a bad ignitor in the ballast. Do not measure voltage going to the bulb, it's in thousands of volts and you risk getting shocked.
 

·
Registered
Joined
·
715 Posts
Discussion Starter #6
Its a buzzing noise and its not the whinning noise that the headlights make. Its almost like when you have a dead battery just not nearly as loud. ill try those tips when I get a chance Thx guys
 

·
Registered
Joined
·
834 Posts
did you figure out the problem? I have the same issue now.. the passenger side wont turn on at all.. i checked the fuse and they are fine (bulbs and ballasts are fine too)
 

·
Super Moderator
Joined
·
19,540 Posts
did you figure out the problem? I have the same issue now.. the passenger side wont turn on at all.. i checked the fuse and they are fine (bulbs and ballasts are fine too)
If both 15A ballast fuses are good and bulbs are known to be good, then I'd check power feeding the ballast. Your HEAD LP relay may be faulty if it doesn't read running battery voltage. Sometimes the socket connector corrodes out if the housing takes on any condensation.
 

·
Registered
Joined
·
91 Posts
i have a similar problem that i really need to fix!!!
both low beams work fine, full power drl works fine but when i tun my high beams on it's just the driverside!!! i tried different bulbs and it still does the same thing!!
the high beam indicator on the cluster DOES NOT turn on either!!!
would this be related to the DRL relay?
 

·
Super Moderator
Joined
·
19,540 Posts
i have a similar problem that i really need to fix!!!
both low beams work fine, full power drl works fine but when i tun my high beams on it's just the driverside!!! i tried different bulbs and it still does the same thing!!
the high beam indicator on the cluster DOES NOT turn on either!!!
would this be related to the DRL relay?
Hmm...So just i have this right. You do have the DRL full power mod but when you turn on your highs, only the driverside works and passengerside stays off, correct? Does the passengerside ever work? I'm just trying to narrow this down to the problem.

It'd be nice if the members who have had previous problems to post up an update. Maybe they just don't like my info:(
 

·
Super Moderator
Joined
·
19,540 Posts
Ae86_driver, I'm guessing it's the passengerside that doesn't come on because when that bulb lights up, it also feeds the high beam cluster indicator. Unfortunately I'd be willing to bet one of the two contacts in the DRL relay(pictured above) is bad, especially if the driverside high beam comes on and the 10A H-LP R UPR fuse is good near the battery. The ground is shared through the relay, so that part is ruled out if at least one high beam works. That fuse basically feeds the positives into that relay and the relay closes when the highs are turned on. If the passenger side bulb never lights up when the highs are turned on, and it's not a bulb(obviously not), then the electrical path through the relay is bad and not closing. If you have a digital voltmeter, you can test the red/white wire at the passenger high beam when they are turned on. To ground, that wire should have 12 volts. The relay is the only thing between the fuse mentioned and that bulb, so no voltage would also verify the relay is bad. The only other possibility is that you have an open wire from that bulb to relay, but if it works at any point, then it's most likely the relay. This relay is very expensive(~$130), so if the above sounds right, then I would source one off ebay or a junkyard. I found one on ebay, link below, as well as the Sewell link to show you.

82841 82840-53010
RUNNING LIGHT VOLTAGE CONTROL RELAY
2002 IS300: OEM Electrical (SWITCH & RELAY) Replacement Parts

Here's a used one for $65
01-05 lexus is300 RUNNING LIGHT VOLTAGE CONTROL relay | eBay
 

·
Registered
Joined
·
91 Posts
dude, jason you're always there with help bro THANK YOU!!!!!

and you guessed it, full power drl both driver and passenger side work fine the only problem is no high beam indicator on cluster and passenger side high beam doesn't turn on.
*the passenger side light never comes on or flickers..

thanks for breaking it down, it really helps with the learning process..

i started to look for the drl relay and after seeing the prices i wanted to research it a little more before purchasing!
 

·
Super Moderator
Joined
·
19,540 Posts
Okay, glad I could help. A meter and testing this would verify my opinion, but sounds like the relay and is the only other thing besides the.socket or it's wiring. If i find it cheaper i'll let you know if i find it cheaper. I'd be ok with used. Should be a plug and play for both connector A and B.
 

·
Registered
Joined
·
354 Posts
bringing back an old thing but Im trying to disable the DRLs. The plug is already unplugged but still work. SO its time to unplug the relay.. BUT maybe its cause they have never been unhooked but how in the world do i unplug them lol they dont even budge
 

·
Super Moderator
Joined
·
19,540 Posts
bringing back an old thing but Im trying to disable the DRLs. The plug is already unplugged but still work. SO its time to unplug the relay.. BUT maybe its cause they have never been unhooked but how in the world do i unplug them lol they dont even budge
To delete the DRL's only, just unplug the DRL resistor. I actually have mine on a switch. It's on the passenger strut tower and won't effect your highs. Just wrap the connector with a few wraps of tape up to keep it clean. The bulbs are in series and run at low voltage in DRL mode. The connectors both on the resistor and relay are locked connectors, you simply need a small flathead screwdriver to hold the tab down and at the same time pull to release.

Unless you're saying that even with the resistor unplugged they are lit, then that must mean they are on full power all the time. Is that correct? I guess you're referring to the DRL relay connector behind then passenger headlamp. You shouldn't have to mess with that. There's a few options that can be done, removing the resistor being the easiest. But if they are on full power all the time then that's a different story. Is that the case? The DRL relay can't be taken out of the equation because it also handles the highs as well.
http://my.is/forums/f64/drl-mods-full-power-disable-350087/

Does this help?

(edit-engine block ground shouldn't be terminated there though lol)
 

·
Registered
Joined
·
1 Posts
Everytime you turn on your headlights, the DRL relay(#3/#4) pictured above turns on. This only turns the relay on so if/when you flip your high beams on, they come on at full power. So basically, that's all that relay above does, turns the DRL's to full power highs wether you turn on the highs or not(does not control headlights). Unless that relay's coil is going bad and reducing voltage going to your ballasts, then there is no need to replace it. You can try unplugging both connectors at that relay and give the headlights a try, but I doubt it will have any effect on your headlight problem.

If your new bulbs don't work, then it could be the ballast, bulb socket(look for corrosion), or power feeding the ballast. There's only one headlight relay, so if there is no problems with the one headlight, then it's more likely the ballast or bulb of the new bulb doesn't work properly.

One other thing, relay pictured should always click when the headlights come on, if it doesn't then there is a problem with power feeding the headlight ballasts(because that's where power comes from to turn the relay on). Try your high beams the next time you suspect that the DRL relay doesn't click or when the headlights turn on. Like I said, it's strictly part of the DRL's/high beams only, but a bad coil can reduce power going to one ballast...I'm kinda doubtful there is a problem with that relay though.
Hey I’m hAving kinda same issue after using a
Everytime you turn on your headlights, the DRL relay(#3/#4) pictured above turns on. This only turns the relay on so if/when you flip your high beams on, they come on at full power. So basically, that's all that relay above does, turns the DRL's to full power highs wether you turn on the highs or not(does not control headlights). Unless that relay's coil is going bad and reducing voltage going to your ballasts, then there is no need to replace it. You can try unplugging both connectors at that relay and give the headlights a try, but I doubt it will have any effect on your headlight problem.

If your new bulbs don't work, then it could be the ballast, bulb socket(look for corrosion), or power feeding the ballast. There's only one headlight relay, so if there is no problems with the one headlight, then it's more likely the ballast or bulb of the new bulb doesn't work properly.

One other thing, relay pictured should always click when the headlights come on, if it doesn't then there is a problem with power feeding the headlight ballasts(because that's where power comes from to turn the relay on). Try your high beams the next time you suspect that the DRL relay doesn't click or when the headlights turn on. Like I said, it's strictly part of the DRL's/high beams only, but a bad coil can reduce power going to one ballast...I'm kinda doubtful there is a problem with that relay though.
hey having I’m having the same issue after using a autozone power inverter accessorie only my high beams work and both small 15a fuses for the headlights blow instantly I noticed ! I wasn’t able to troubleshoot any further any ideas guys ty
 
1 - 18 of 18 Posts
Top