Only hi beams work ...no low beams . Lamps and fuses are good. Replaced relay, no change. Keep reading about ground wire from lights can not find it

PAWEL IS A BOT. HE POSTS GENERIC ANSWERS. AND OVERLAYS NAME OF YOUR CAR. 82 GENRIC ANSWERS HIM
AND LIES ABOUT IGN SWITCH.
NOW YOUR CAR.! FACTS, ONLY, 1 CAR
LEARN TO USE THE DMM , CORRECTLY;
HEAD LAMPS ON.(SWITCH) NO KEY IS NEEDED FOR HL.
IS DRIVER LEFT OR RIGHT,? IN USA LEFT.
IS HIGH AND LOW BEAMS DEAD LEFT? No TOLD AT ALL.
PUT METER BLACK LEAD TO THE BATTERY NEG LUG
THEN PROBE RED TO ALL WIRES OF DEAD LAMP 1 BY 1.
12VDC IS GOOD 0 BAD
IF LAMP GROUND PIN READS 12VDC <<< GROUND FAILS.

LEFT LAMP USES GROUND LUG G101. IF R

CAR HAS DRL. SO DRL AND MANUAL LAMPS FAIL
HIGH , LOW , AND FLASH HIGH>? NOT TOLD
DOES ENGINE RUN? OMG NOT TOLD.
THIS CAR RUN HL RELAYS BY BCM CONTROLLER BRAIN


FUSE ARE ON THE OUTPUT OF ALL HL RELAYS
SO IF ALL FUSES INPUT(TOP) ARE DEAD,THAT MEANS
BCM IS FAILING. OR THE SWITCH TO IT.
OR FUSES BLOW TO BCM
WE SCAN THE PCM/BCM TO SE WHY.


HEAD LAMPS ON THE 4 FUSES ALL 4 RIGHT SIDE ARE
12VDC, IF NOT BCM IS MESSED UP, OR RELAY DEAD.
HE LOW BEAM RELAY RUNS BOTH SIDE
SAME WITH BEAM. A RELAY FOR IT.
DRL HOT ONLY IN DRL MODE.
DRL; HAS A SUN SENSOR (AUTO MODE)


BOTTOM HERE IS HEAD LAMPS.SIDE.

HEAD LAMPS ON USA WORK EVEN KEYOFF
SO DOES BCM TO DO THAT, MAIN BATTERY NOT DEAD

If you have already replaced the switch and checked the connections, there could be a few other possible reasons for the low beams not working:

1. Relay issue: The headlight relay controls the low beams. Check if the relay is functioning properly, if not, replace it.
2. Fuse issue: Check if the headlight fuse is blown, if so, replace it.
3. Wiring issue: There may be a problem with the wiring between the switch, relay and lights. Inspect the wiring for any damage, such as frayed wires, loose connections, or melted insulation.
4. Ground problem: Make sure that the ground connection to the headlight is secure.
5. Light bulb problem: Finally, check if the low beam light bulbs themselves are functioning.

If these checks do not solve the problem, it may be necessary to take your truck to a professional mechanic for further diagnosis and repair.

This is for your head lamps. Hope you can read it? There is hi and lo beam relays. The top terminals in diagram for relays, hot all the time, use a test light to check for voltage, unplug the relay. At the actual head lamps in diagram, the top wires are voltage for hi or lo beam, the bottom wire is ground.
At either relay, the load side of relay is that line with arrowhead, terminals 30 and 87. The control side of relay needs voltage and ground, terminals 85 and 86. Your bcm grounds either one of those relays depending on signal from headlamp/dimmer switch.

The headlamps are controlled by the BCM - body control module , do you know what that is ? The headlamp switch is a input to the BCM ,the BCM energizes relays to turn on the headlmps , low beam relay , high beam relay , DRL relay . These relay's are PCB - printed circuit board relay's ( non - serviceable ) If found to be bad the whole under hood fuse box would need to be replaced .
Low Beam Headlamp Operation
The low beam headlamps may be turned ON in 3 different ways:
• When the headlamp switch in the HEAD position for normal operations
• When the headlamp switch is in the AUTO position, for automatic lamp control (ALC)
• When the headlamp switch is placed in the AUTO position, with the windshield wipers ON in daylight conditions, after a 6 second delay
Battery voltage is applied at all times to the coil and switch sides of the LOW BEAM PCB Relay located in the underhood fuse block. When the headlamp switch is placed in the HEAD position, ground from G202 is applied through headlamps ON switch signal circuit to the body control module (BCM), signaling the headlamps ON request. In response to this signal, the BCM applies ground through the headlamp low beam relay control circuit energizing the low beam relay. With the relay energized, battery voltage is applied through the switch side of the relay, the left and right low beam fuses, and the low beam supply voltage circuits illuminating the low beam headlamps. Ground for the left headlamp is provided at G101 and the right headlamp at G100.

Do you know what B codes are ? BCM - DTC'S - diagnostic trouble codes , need a factory scanner or professional one to view these codes , not autozone or advance etc....Having a qualified repair shop check your vehicle would be your best bet.

DTC B2575 00: Headlamp Control Circuit

Circuit/System Description
The vehicle headlamps are controlled by the body control module (BCM) based on inputs from the headlamp switch and the turn signal/multifunction switch. The headlamp switch has four positions: Off, Auto, Park, and Headlamps. The default headlamp switch position is Auto, in which the BCM uses the ambient light sensor to determine when headlamps are needed. The Off portion of the headlamp switch is a momentary switch which overrides the automatic headlamps and will turn off the vehicle headlamps. When in the Off position, the headlamp switch grounds the headlamp switch headlamps off signal circuit, prompting the BCM to turn off the headlamps. The Park position of the headlamp switch will only illuminate the vehicle parking lamps. The Headlamp position of the headlamp switch will illuminate both the parking lamps, as well has the headlamps. With the headlamp switch in the Headlamp position, the headlamp switch headlamps on signal circuit is grounded, prompting the BCM to turn on the headlamps, regardless of other factors such as ambient light.
The headlamp high beams are controlled through the flash to pass switch and the headlamp dimmer switch, both located in the turn signal/multifunction switch. The flash to pass switch is a momentary type switch, designed to illuminate the high beams as long as the switch is held. With the switch closed, the flash to pass switch signal circuit is grounded, prompting the BCM to turn on the high beam lamps. The headlamp dimmer switch allows the operator to select between full time high or low beam operation. Unlike the flash to pass switch, it is not a momentary switch. When the headlamp dimmer switch is in the high beam position, the headlamp dimmer switch high beam signal circuit is grounded. This prompts the BCM to turn on the high beam lamps.
The BCM controls the headlamps based on the inputs explained above. When a low beam request is received, the BCM grounds the headlamp low beam relay control circuit. This energizes the coil in the LOW BEAM PCB relay, causing the relay switch to close. This then applies B+ to both low beam headlamps through the LT LO BEAM and RT LO BEAM fuses, illuminating the low beam headlamps. When a high beam request is received, the BCM grounds the headlamp high beam relay control circuit. This energizes the coil in the HIGH BEAM PCB relay, causing the relay switch to close. This then applies B+ to both high beam headlamps through the LT HI BEAM and RT HI BEAM fuses, illuminating the high beam headlamps

I can only help with testing. You have to do the testing. Hope you can read diagram. You have a hi beam and lo beam relay in under hood fuse box, because there are no terminal numbers on the relays, it makes me think the relays are soldered into the fuse box and you can't pull it out, which makes testing a little harder. You can try to pull out, don't damage it. See the top wires to relays, hot all the time, I want to know if that voltage is there? There are also, right/left hi/lo fuses for head lamps, turn on headlamp switch, check fuse circuits for voltage, use a test light. The headlamp/dimmer switch is input to bcm, the bcm grounds the control side of headlamp relay.
In the diagram for headlamps, the top wire is voltage, the bottom wire is ground.

Could it be faulty lamps? Well worth replacing IMHO

No on the fuse . The LH HDLP and RH HDLP fuse in the fuse block - under hood, supply battery positive voltage to both low and high beam lamps at all times. For manual operation, when the headlamp switch is in the ON position, the headlamp switch supplies ground directly to the headlamps and to the body control module (BCM) on the headlamp low or high beam signal circuit, depending on the position of the headlamp dimmer switch. The BCM uses this signal to determine if the conditions are present to illuminate the daytime running lamps or park lamps.
The headlamps may be turned on 2 different ways. First, when the driver places the headlamp switch in the ON position, for manual operation. Second, with the headlamp switch placed in the OFF position activating automatic lamp control (ALC).For ALC operation, the BCM receives a signal from the ambient light sensor indicating a low or high ambient, outside, light level. Under low light conditions the BCM grounds the headlamp relay control circuit energizing the headlamp control relay. The now closed relay supplies ground through the headlamp switch to the headlamps and the BCM on the headlamp low or high beam signal circuit, depending on the position of the headlamp dimmer switch. When the BCM grounds the headlamp relay control circuit it also grounds the park lamp relay control circuit illuminating the park lamps. The headlamp relay is grounded at G203.
Daytime Running Lamps (DRL)
The low beam headlamps operate at reduced intensity when in daytime running lamps (DRL) mode. The ground circuit to the switch side of the DRL relay has a resistor in-line to reduce the intensity of the low beam headlamps for DRL operation. The body control module (BCM) receives a signal from the ambient light sensor indicating a low or high ambient, outside, light level. Under daylight conditions the BCM grounds the DRL relay control circuit energizing the DRL control relay. The now closed relay supplies ground directly to the low beam headlamps and to the BCM on the headlamp low beam signal circuit. The low beam headlamps now illuminate with reduced intensity. The DRL relay is grounded at G203. Any time the headlamps are illuminated the DRL will not illuminate. Manual park lamps do not effect DRL operation.

There are several reasons why your headlamps an running lights don't work , the headlamp switch is a good one ,plus relays an the DIM - dash integrated module an associated wiring ! Here is how the headlamps work , right out of Buick factory service info !
The dash integration module (DIM) provides battery positive voltage to the signal circuits of the headlamp switch. The signal circuits include the headlamp switch headlamps on signal, the flash to pass switch signal and the high beam input. With the headlamp switch in the ON position, a ground path is available for the headlamp switch headlamps on signal circuit of the DIM through the headlamp switch. The DIM provides ground to either the headlamps high beam relay control circuit or the headlamps low beam relay control circuit of the low beam circuit. The position of the headlamp dimmer switch determines which relay control circuit has ground. The DIM supplies battery positive voltage to the relay control circuits, if the headlamps are necessary. The fuse block - underhood supplies battery positive voltage to both relay switch circuits. When the low beam relay control circuit is energized, current flow is to both low beam fuses and to the low beam headlamps. The headlamps have ground at G103 and at G401. When the headlamp high beam relay control circuit is energized, current flow is to both high beam fuses and to the high beam headlamps. The high beam circuit is divided into a left and right side circuit. The current flow of the left high beam is from the fuse to the left high beam lamp. From the lamp, the current flows to the normally-closed contact of the DRL relay to G103. The current flow of the right high beam is from the fuse to the right high beam lamp. From the lamp, the current flow is to ground at G401. When the headlamp dimmer switch lever is pulled toward the driver, the flash-to-pass switch closes. This grounds the DIM flash to pass switch signal circuit. In response to this input, the DIM energizes the HDLP HI BM relay. Both high beams remain on until the driver releases the switch handle. If the low beam headlamps were on during a flash to pass operation, the low beams remain on. The headlights may be switched to high beam with the opposite movement of the headlamp dimmer switch lever.
By running lights , do you mean park lamps or day time running lamps ?
Park, Tail, License and Marker Lamps
The park lamps, including the license lamps, are turned on when the headlamp switch is placed in the PARK or ON position or anytime the headlights are requested. The fuse block - rear supplies battery positive voltage to the switch contacts of the Park LP relay. When the headlamp switch is in PARK or in ON, the park lamp switch on signal circuit of the DIM has a ground path. The DIM provides battery positive voltage to the control circuit of the Park LP relay. When the park lamps and/or the tail lamps are ON, the DIM energizes the park lamp relay control circuit. This closes the switch contacts. Current flows from the Park LP relay to the LH PARK LP and the RH PARK LP fuses. From the fuse, the current flows to the park lamps. The left park lamps are grounded at G103, G401 and G402. The right park lamps and the right tail lamps are grounded at G103 and G401. The DIMR fuse supplies battery positive voltage to the license lamps and to the DIM instrument panel lamp fuse supply voltage - 1 circuit, for interior lamps dimming. The license lamps are grounded at G401.
The best advice I can give is that you take this to a ASE certified professional repair facility unless your a qualified automotive electric repair person !
Diagnostic Starting Point - Lighting Systems
Begin the system diagnosis with the Diagnostic System Check - Lighting Systems . The Diagnostic System Check will provide the following information:
?€¢
The identification of the control modules which command the system

?€¢
The ability of the control modules to communicate through the serial data circuit

?€¢
The identification of any stored diagnostic trouble codes (DTCs) and their status

The use of the Diagnostic System Check will identify the correct procedure for diagnosing the system and where the procedure is located.

The

old post.(day)
low beams, they are.
both low beam lamps.dead but are PARK/tail dead too?. (a key fact needed here to save time finding cause)
there are more that one cause.
but fuses are first, some cars have 2 fuse.
one for highs and lows.
or for left and right.
they do that so at least some lights work and not all go out at once, on a dark rainy night on a country road (or cliff road)
GEO, the car brand GEO is sold mostly in USA and Canada
if in CANADA the law says its DRL lamps.
in canada they have a Drylight Running lamps and laws and have a unique controller for that (DRL module) and can fail and mess up lamps. so GOT DRL>?
on this car the fues box shows, left and right HL
the next question is does it run a relay.
answer,
DRL, the DRL module runs low beams totally so that be first.
and its DRL relay.
non DLR metro, works like this
im reading the online schematics for you, and so could you.
the no-DRL is brutally simple.
the fuse runs the lamps direct, means lamps hot all the time.
the park and head light switch, grounds the low beam wire feed.
no relays , magic , DRL just a simple switch, in the combo switch.
for you or others seaching Metro head lamps.
here is the schemo.
red/wht wire must be 0v on low beams if not switch bad.
if g200 is good, but g200 is used in highs so can NOT BE BAD.
as you can see the switch grounds the HL lines below.
to make the lamps GLOW,

good luck to metros

Power flows from the battery to the main fuse. Then it flows to the control coil and contact side of the headlight relay. When you turn on the headlights, the headlight switch provides ground to the control coil in the headlight relay and that operates the contacts. The contacts allow power to flow to the right and left hand headlight fuses. Power flows to the headlights. The headlight switch is what provides ground to the high and low beams on the headlights.

To diagnose, remove the headlight relay. Using a voltmeter, check for battery voltage on terminals 3 & 4 in the socket with the key in the RUN position. Then turn on the low beams. Test for good ground on terminal 1 in the socket. If you're not getting ground, then you've got a problem with either a bad headlight combo switch or a bad ground. If you get good ground on terminal 1, reinstall the relay, turn on the low beams and test for power in the headlight sockets. If you get battery voltage, that confirms you've got good fuses and wiring up to that point. Next, check for good low beam ground on the red/green wire in the bulb socket. If you're not getting good ground, it's either a bad combo switch or bad ground from the combo switch. Then turn on the high beams and check for good ground on the red/yellow wire in the bulb sockets.

It wouldn't hurt to clean the ID ground on the left side of the instrument panel, but based on everything you've said so far, this sounds like a bad combo switch