Hello and Happy New Year to everyone,

Any help would be appreciated. We recently purchased a 2002 RX300 in excellent condition. After driving it for several weeks, we realized that the low beam lamps aren't coming on at all. High beams and running/parking lights are fine.

We have checked the low beam fuses and they are fine. The bulbs themselves look fine as well. Is there a way to test the bulbs to see if they are okay?

If they are, does anyone have any thoughts as to what the problem might be?

Thanks

 

Have you tried both manual and auto mode?

Salim

 

Welcome to the Club.

Have you tried putting in another bulb?

Recently I went and bought some new Sylvania bulbs for my RX and there weren't expensive at all over at Autozone. (I think under $20 USD for two) and fit just fine.

 

Thank you to both,

Yes - it's the same in both modes - auto and regular. High beams fine; running/parking lights fine. Just no low beams.

No - I haven't tried any other bulbs. I think I am going to purchase one single one to see if replacing helps. They just look brand new!

Thanks for the help.

 

At least when I went to Autozone, they sold them in packages of 2. I have the issue when I was in Mexico where one bulb went on the fritz (kept having to fiddle with it for the low beam to come on) and finally realized it wasn't coming back on one day. Eventually found one around my uncle's shop.

 

Does your daylight running headlamps light? If not then it is possible your DRL relay is bad or corroaded. There are two fuses for the low beams 15A in the fuse box near the battery on the left fender well, There is a 7.5 amp fuse for the DRL relay and lights in the small fuse box mounted above the radiator near the battery. I suspect that fuse is bad, or the DRL relay is bad or corroaded. Both fuse boxes are in the engine compartment.
in your owners manual are the locations of all three fuses.
DRL is fuse number 1
low beam for left and right headlight are fuses 2 and 3

 

My guess would be the relay if both are out. Bulbs CAN look good but be bad. The way I always tested bulbs (all bulbs) was to hold the bulb FIRMLY in 2 fingers and give it about 3 or 4 SOUND thumps with my R. (obscene) finger, If it is broken OR ready to break that will reveal it. If it is sound, THE THUMPING WILL NOT BREAK THE FILAMENT! Saved a lot of comebacks when the bulb that was getting weak, but worked, came back a week or two later burned out.
I am somewhat confused because this is the second time tonight that I have responded to a question that concerned DRL's. (2 different forums) Every DRL I have ever seen uses the HIGH beam at 50%, NOT the LOW beam. And as Thomas said, a good chance it is the fuse.

 

Correct, the DRL has to do with the high beam ckt.

sonofabc's problem is with lowbeam and these are the ways to trace his problem

VOM to trace voltage or check the continuity of the bulb. For voltage trace, one would need the wiring diagram.

Lexmex suggestion of doing a bulb swap seems like the easiest DIY approach.

Salim

 

the relay for the headlights is in the engine compartment fuse box...I was asking about the DRL but did not realize it was tied to the high beams...thanks for the info. I was thinking the relay was stuck or the 7.5 amp fuse was blown. Voltage for the low beam could be check at the fuse holder (15A) at fuse 2 and 3 under the larger fuse box on the fender wheel. If there is voltage there, than the lights or wiring is bad...very supicious about both being out, as Code 58 said probably the headlight relay.

 

I have the same problem, however I tried new bulb in the low beam and switched out the relay with the one from fan 1...same exact relay. Still no low beams under any condition.
Any other ideas?

 

I think I have a similar problem.

There appears to be three DRL relays once I got the cover off. How do you get the relay out of the holder to check it?

 

All the relays I have ever seen are a blade type (4or5 blade) and simply push straight in. Because you have the resistance of that many blades it takes a little bit of effort to get them out. Maybe a SLIGHT wiggling side to side will help. You should be able to tell if the electro-magnet that pulls the contacts together is working simply by feeling the relay when the appropriate switch is operated or if it is quiet you can easily hear when it operates. When you get the relay out you can check it with jumper wires. Virtually all relays have the schematic on the side and if you have any mechanical or electrical knowledge or even common sense, it's easy to figure how to jump it to see if it works. Maybe i shouldn't make it quite that simple... I have worked with them for way too many years, but they are really a simple device and since almost everything on a car is run through a relay anymore, it's not a bad idea to know how to diagnose them. The good part is they are rather trouble free, most of them lasting the life of the vehicle.

 

On thing I might mention concerning those of you who are or will wrestle with electrical problems that at some times can be rather maddening. I have a rule... ALWAYS try the simplest things first! Check fuses 1st. if the circuit has fuses. That doesn't mean simply looking at them. Buy a cheap test light and test the juice going in and coming out of a fuse. Seems pretty simple...right? If that tests OK and the device still doesn't work, remove the fuse and "reset" it a couple of times. Sometimes something that simple will fix the problem. Fuses often build oxidization on them which manifests itself as a slightly "smokey" discoloration (slight blackening) as the result of the transfer of electricity through it. (this is on the blades) It normally doesn't give any problem, but a fuse might carry the juice from that test light and not be able to carry the 5-7 amps that it is required to carry. Next, try to go to the end user of that voltage and check backwards from there. I.E., test the voltage coming into the socket (with the test light) and test backwards from there as much as possible. I have a short and open circuit tester that makes it easier, especially to find a broken wire in the insulation (notice I didn't say damaged, sometimes it's corroded) Doesn't happen often but I have seen it happen and it can drive you nuts. These are some very basic and simple principal (there are a whole lot more of them) but they may save you hours of chasing your tail. Not fun!

 

Had the same problem, checked fuses and bulbs..appeared fine. Read this thread and just for grins I replaced the DRL 7.5A (which looked fine) and it worked...sigh...had me stumped for 1 week

 

I'm retarded, thought it was fixed but turns out that I had the high beams on and thought it was the low beams...still looking for a solution.

How can I testthe DRL relay itself?

Every other light in the unit works, just the low beams