2000 Corolla CE: Headlights wont turn on, lock/window control switches non functional

Hello everyone,

My father drives a 2000 Corolla CE. Recently the headlights stopped working. All the fuses appear to be okay according to a multimeter. The failure was not immediate; the headlights would turn on sometimes and not other times. This went on for a period of time and now they will not turn on. Does anyone have suggestions as to where I can begin troubleshooting this?

Also as you know there are switches embedded in the armrests on the doors which control the power windows and power door locks. All of the switches in the car stopped functioning. Again the failure was not immediate sometimes we could get a window down or the doors locked / unlocked and now they simply don't function. I believe the actuators and power window motors are fine. When the key is placed in the drivers side door the locks will unlock / lock appropriately. Also I would not think all 4 window motors would die at the same time. Does anyone have suggestions as to where I can begin troubleshooting this also?

Regards, Andrew

Reply to
Andrew Budwill
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I would check for voltage at the headlights and work backwards to the relay. If the relay is good, then you will need an electrical wiring diagram to check the combination switch and harnesses.

You can get online access to U.S. factory service manuals ar techinfo.toyota.com for $10/day.

Again, you will need an electrical wiring diagram to diagnose. Most likely, the master switch is bad so start by checking there.

Reply to
Ray O

I appreciate your response Ray. I will troubleshoot accordingly and if I think to stop back in I'll post what was broken.

Andrew

Reply to
Andrew Budwill

Hello Ray,

So I had was visiting my parents tonight and had my multimeter. I checked for voltage at the headlight harness. The headlight harness would put out

6v when the normal beams were on and 4v when the high beams were on. This made zero sense to me. The bulbs light up when I hook them to a 12v power source. It seems not enough voltage is being supplied to the headlight harness.

I am not quite sure what to check yet. I checked all the relays and they are functional. I checked all the fuses for continuity and they are good.

Not being very familiar with Toyotas, I assume the headlight harness should be receiving 12v not 6v/4v.

Do you have any advice on how I should proceed?

Regards, Andrew

Reply to
Andrew Budwill

When you checked the voltage at the headlight harness, how did you ground the meter? Did you use the ground at the headlight connector or did you ground the meter to a nearby chassis ground?

If you used the headlight connector's ground, then check to make sure that wherever the that wire is grounded, the cocnnection is good. You can also check continuity between the headldight connector ground wire and the chassis - you should have continuity with the chassis at the point where the connector is grounded. If the ground connection is good, then check the voltage passing through the headlight relay and check for a loose connection somewhere.

If you used a nearby chassis ground to check voltage at the headlights, then check for a cut or chafed wire somewhere in the circuit.

Reply to
Ray O

Hello Ray,

This evening I stopped by my parents house. Mysteriously I measured the voltage at the headlight harness again (using the ground in the harness) and this time read 12 volts. I tried to turn the headlights on, all the relays clicked (headlight relay near the battery, DRL relay near passenger side fender, dimmer relay when I tried to brights) but the lights did not respond. I hadn't eaten dinner yet so headed inside to grab some food. When I came back out NONE of the relays would respond at all when I flipped the headlight switch in the car.

I removed the relays 1 by 1 and hooked them up to a 12 volt source, they all work properly.

I tested for voltage where the headlight relays plugs in, I used the battery as a ground and read 12 volts. I then checked for continuity between where the relay should have been grounded to the battery and continuity was not present.

According to the schematic in my shop manual the grounds for all the relays run to the DRL main relay harness. I am beginning to suspect the DRL relay which if I understand correctly is located behind the glove box.

Do you have any thoughts?

Andrew

Reply to
Andrew Budwill

I'm running out of thoughts. You can check the DRL relay, and since the combination switch (headlight switch) has been problematic on these vehicles in the past, I would check that as well.

Reply to
Ray O

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