AlanVR

I have a 1999 RX300. the Daylight Running Lights do not work at all, not in any mode that they should, even when the parking light switch is activated. The front marker lights do not work at any time either when the headlights are on.the rear tail lights and the rear marker lights do work when the parking/headlight switch is activated. there is no voltage to the #1 fuse in the front fuse/relay box and the fuse tests good. All the other lights including fog lights work as they should in all modes. is it possible that the parking brake switch for the DRL has failed or is there another problem?

salimshah

Welcome to ClubLexus.

Do the high beams work?

Salim

AlanVR

Thank you salim for the quick response. I rechecked the high beams and see that only the right one works. I hadn't noticed it before. I'll fix that now since I have a bulb. And I'll wait for your reply to this as well.

Alan

salimshah

DRL connects the high beam filament in series to run them at half the brilliance. Since one is popped, the DRL will not come on. Once you replace the blown out bulb, your DRL should come back.

Salim

AlanVR

Thank you Salim. Everything just as it should be now. I am puzzled tho, the warning light to indicate a bulb out for the high beam was not showing on the instrument panel. I noticed that when I first started to look for the problem.
Alan

salimshah

I dont think there is such a warning light. If your vehicle has factory HIDs, you may have auto-leveling warning light, but there is no warning light for headlight(s) burnt out. Had you been driving at night time and turn the high beam, your problem would have been obvious. Even spotting DRL not working is hard during the day ,,,, an observer has to inform you.

Salim

copterman

I have similar issue with Driving Lights on 2002 RX-300. Driving lights do not work, yet high beams using same bulbs do work. Instrument panel Rear Light Failure Warning Light illuminates when brake pedal is depressed - that's usually when the Driving Lights come on. Check of brake and tail lights reveal them to all be working properly. Checked #1 CB which powers DRL system; and it's good. While at it, I checked all bulbs on the car; and all work properly, except the Driving LIghts.

Must be a quirk in the circuitry, which alerts driver to the fact that "a bulb" needs replacing.

Would like to know if anyone else has had similar problem before I buy 2 new bulbs.

salimshah

Welcome to club lexus.

If your brake light waning light comes on, on first application of brake then one of the 5 bulbs is blown or at least one is out of spec.

If high beams (not the head lights) work, and DRL doers not work then the DRL relays are malfunctioning.

Salim

copterman

Thank you Salim, for the intuitive response. Could be that we have an impending brake light or tail light bulb failure, happening coincidently with a DRL relay failure. It's my wife's car; and I wasn't driving at the time the warning light first came on, so cannot say for sure which came first. Will keep close tabs on the rear lights; and replace whichever bulb when it fails. I keep spares on hand - our last bulb failure was 7 years ago.

Is there a procedure for checking the DRL relay; or is a simple multi meter continuity check good enough?

Thanks very much for your help.

salimshah

I did not write clearly for you to understand ...

Does your warning light come on when you apply the brake first time after start and does it reset when you turn off the ignition and pull the key out. If yes then it is one of the 5 brake lights.

There is no interaction of tail lights with DRL. If your parking brake is partially engaged then DRL truns off.

Salim

copterman

Salim, thank you again for your clarification message. I got it.

In the meantime the mystery has sorted itself out for the moment. Couple days ago the Rear Light Failure Warning Light went out, and stayed out; and the Daytime Driving Lights come on when the parking brake is released, as they should; and stay on. I checked everything out thoroughly several times; and all functions are back to normal.

Only thing I can think is that we have had lot of rain here in South Florida the past couple of weeks, with very high humidity; and perhaps some moisture got into the system somehow that was causing this unusual failure mode. Anyway, all the lights (and warning systems) are working normally now; so nothing to do but monitor and see if it happens again. If it does, I'll post a message.

Thanks again for your help.

copterman