Benjamin T

iTrader: (2)

our canadian-spec 00 rx300 just experienced problems with it's factory-installed DRL system.

it used to activate the high beams at low power once the e-brake is disengaged, but it has since stopped working. it was also discovered that when manually turning on the hi-beams via the switch, only the driver's side hi-beam comes on, not the passenger side. inspection of the passenger side hi-beam bulb shows that it is still in working condition.

a check of the fuses for the DRL setup shows power going through them, using a voltage tester, but i don't know how to test the 3 relay packs (located in the DRL module mounted about the radiator in the engine compartment).

i'm at a total loss... dealer wants straight time to diagnose. can someone please help?

lexus114

My heart goes out to you my friend,unfortunately my electrical knowledge is weak. Although it sounds like something simple (from what I do know) hopefully,someone on here can be of more help.The other alternative would be an independent shop have a look.

bob2200

It turns out that the USA models also have DRL (daylight running lights). Looking at the diagram, it looks like there are separate 15 amp fuses for the right and left highbeam (one labeled H-LP R UPR and the other H-LP L UPR).

salimshah

Before getting in to more details ..

try swapping the the right high beam bulb with the left and if the problem moves with the bulb, buy a new one. [if the check you mentioned was other than the swap]

For lot of electrical stuff the test procedure needs a thorough understanding of the instrument.

case: My neighbor had a boat-trailer and he was using voltmeter to test availability of 12v ... guess what, he had a corroded joint .. the voltmeter would dutifully report 12v but the bulb would not light up as the corroded joint would not support the current. Had he checked with the load or with an actual bulb (low tech test procedure) he would have found out.

Salim

Benjamin T

iTrader: (2)

i just tried swapping bulbs... no effect.

it seems like the canadian models don't have the same setup... i can only find a single 15amp fuse and 3 drl relays, but the relays are not marked as to what they do.

lexus114

That seems strange,it doesnt tell you on the lid of the fuse box? How about in the manual? is it listed in their?

bob2200

Again, from the diagram, there is DRL relay #3, which has the coil on pins 3 & 5. Pin 2 is switched between pins 4 and 1. Pin 4 is attached to the DRL resistor, but in Canada the resistor is shorted out by a "short connector". So, I suppose in Canada you have full power highbeams in DRL mode.

DRL Relay #2 has the coil coming off the body ECU (maybe a reset is in order??). Pin 4 goes to the ECU and pin 3 is the other coil lead. The contacts are pins 1 & 2.

DRL Relay #4 has the coil on pins 3 & 4 and contacts are pins 1 & 2.

There is no DRL Relay #1, but perhaps relay #1 is considered the headlight relay.

If I had to guess, I'd say DRL relay 3 activates the DRL dropping resistor (in the USA model case), DRL relay #2 activates, based on a signal from the Body ECU computer, and DRL relay #4 takes power from the DRL fuse and applies power to the highbeams.

Good luck.

bob2200

Thinking about it some more, it looks like you can rule out the relays, since they are supposed to control both left and right DRL functions. Ditto with the body ECU.

salimshah

Next step would be to examine sockets and wires .. I hope you dont have ultra brights that could have drawn more current (meltdown etc). Then I would look at the relays ... you can swap identical relays ..failing all that you will need the wiring diagram and I would recommend using test bulb instead of voltmeter.

Salim

Benjamin T

iTrader: (2)

the hi-beams run at 1/2 intensity with the DRL on. they turn off when the parking brake is applied, or the low beams are turned on.

Benjamin T

iTrader: (2)

here's a pic

Benjamin T

iTrader: (2)

another pic

salimshah

Super Clean ... Lexmex are you envious!

Salim

Lexmex

Benjamin T

iTrader: (2)

meh... did i miss something? am i the only one who cleans the engine bay?