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So for some reason, suddenly both my low beams dont work.
High beams / DRLs work fine
Park Lights work fine
Tail lights work fine
Turn Signals work fine
Fogs work fine
But my low beams wont fire on?! My car is a factory halogen, no afs. Previous owner had an aftermarket hid kit installed, Checked all fuses relating to low beams, also checked the HD LP relay in the fuse box right below the battery, checks out good. Whats weird is the diagram for that fuse box says there is a 30a fuse for the low beams and a bunch of other fuses on the top middle portion, but the physical fusebox only has a clear plastic that runs across the top portion of the fusebox, with no fuses whatsoever (Will attach a picture). Also checked fuses for left and right low beams from the fusebox on the driver side, all aren’t blown. Tried disregarding the hid kit and plugging in a regular halogen bulb, still no avail. Im lost right now and I work night shifts, so having low beams is a big deal for me. Any input will be greatly appreciated.
*Below is the picture of the fuse box, as you can see there is a long white plastic piece that runs across the top, while the diagram states there should be fuses there. confused
The clear panel has a slew of fuseable links. Look at the underside of the lid. It is marked and all have a purpose.
The left side of the car has the fuses and relays for the headlamps.
If I read that right, you inserted a known good bulb into the connector feeding the HID conversion kit and the bulb did not power on, is that correct?
Step one is to take that same connector and verify one side goes to ground. A) use an ohm meter to ground. Should be 0.5 ohms or less. B) use test lamp from connector ground to Battery positive. The lamp should light.
Next you test the relay. Remove the relay and verify it has 12V present. Turn the lights off and on and FIND the signal wire that toggles ON to power the relay.
Hint - the bottom of the relay has the pin out. Look it.
Yes I tried basically removing the hid kit and plugging in a halogen bulb the same way it was wired to from factory. Will try your suggestion, the hid kit basically has the ballast and I believe a relay, both of which just plug into the factory harness, I didnt notice any splicing.
The clear panel has a slew of fuseable links. Look at the underside of the lid. It is marked and all have a purpose.
The left side of the car has the fuses and relays for the headlamps.
If I read that right, you inserted a known good bulb into the connector feeding the HID conversion kit and the bulb did not power on, is that correct?
Step one is to take that same connector and verify one side goes to ground. A) use an ohm meter to ground. Should be 0.5 ohms or less. B) use test lamp from connector ground to Battery positive. The lamp should light.
Next you test the relay. Remove the relay and verify it has 12V present. Turn the lights off and on and FIND the signal wire that toggles ON to power the relay.
Hint - the bottom of the relay has the pin out. Look it.
So I just tested the bulb socket (factory harness) and im getting 12v out of the power wire and im getting ground, but when I test for continuity(shorts) I have little resistancw, but no enough to make my multimeter beep to suggest a short. tested the bulb directly to the battery and it lights up. im lost now since i know the socket is getting power
So I just tested the bulb socket (factory harness) and im getting 12v out of the power wire and im getting ground, but when I test for continuity(shorts) I have little resistancw, but no enough to make my multimeter beep to suggest a short. tested the bulb directly to the battery and it lights up. im lost now since i know the socket is getting power
That leaves you with two paths. OK, maybe others....
As you know, a DMM draws no current so we need a load like a lamp. That is, the plug may show 12V but when asked to deliver 4 amps, it fails.
Does the bulb light even a little?? If yes, measure from Connector Ground to Battery Ground with bulb connected as listed. The DMM voltage should read zero volts. What is it?
Now do the same with the lights on and use the connector +12V.
Connector +12v >> 55w bulb >> Battery Ground.
Does it light?
Connect DMM to connector +12 and Battery +12V. What is the voltage?
That leaves you with two paths. OK, maybe others....
As you know, a DMM draws no current so we need a load like a lamp. That is, the plug may show 12V but when asked to deliver 4 amps, it fails.
Does the bulb light even a little?? If yes, measure from Connector Ground to Battery Ground with bulb connected as listed. The DMM voltage should read zero volts. What is it?
Now do the same with the lights on and use the connector +12V.
Connector +12v >> 55w bulb >> Battery Ground.
Does it light?
Connect DMM to connector +12 and Battery +12V. What is the voltage?
Make sense?
I only have basic knowledge and some, what you stated is a little complicated for me, but I will try to figure it out tomorrow when I get home from work. I was working with an led conversion kit (just purchased since I thought the hid kit was shot). So should I buy some test leads from walmart to help me with testing out the circuits and such? I’ve been driving home with only fogs on ane fingers crossed haven’t been pulled over yet, I’ll have the next 3 days off so I will try to figure it out from there. Will update asap
Buy a socket for bulb and any 55w bulb that matches the socket as well as some 14 to 16 gage wire.
A 12v incandescent test lamp not an LED.
A DMM. I'm not sure what you'll find there but hit an automotive store or even Lowes / Home Depot has to better than Wally World.
Maybe some butt connectors 14/16 gage (blue) and electrical tape should do it. And crimp tool.
Buy a socket for bulb and any 55w bulb that matches the socket as well as some 14 to 16 gage wire.
A 12v incandescent test lamp not an LED.
A DMM. I'm not sure what you'll find there but hit an automotive store or even Lowes / Home Depot has to better than Wally World.
Maybe some butt connectors 14/16 gage (blue) and electrical tape should do it. And crimp tool.
Brought my car to a buddy this morning, he has a better dmm (device that conects to your battery positive and negative, and you can also probe sockets while giving power and also checking ground). What he noticed was my passenger side hid kit was put on reversed, basically the kit had negative on positive, and positive on negative. which is weird since the lights still worked. but I was having issues on that specific side, sometimes it wont turn on right away, so I had to switch off my lights and switch on again. He checked everything, and both my low beam fuses arent getting power, but when he gave power to it from the fuse box voila! my low beams were turning on. He ruled out that it was probably my multi function switch (stalk on the left side with headlight functions). Im kind of confused since when I turn on my low beams, the indicator on the dash for the low beams work, just the bulbs on the headlight dont. I just wanted some input on it before I go out and purchase it.
Just out of curiosity, how did you test the Head LP relay? Did you swap another working one or test it on a bench with a meter and power supply? It sounds like the Head LP relay is not engaging or there is broken wire somewhere between the relay and the low beam fuse.
Check and confirm the followings:
1. Check #2, #5 pin on the HEAD LP relay socket, Both should have +12v. If there is no +12, possible blown 30A fuse in the fusible link.
2. Turn on low beam and use a DMM to test pin #1 on the Head LP relay socket for ground. If pin 1 doesn't go to ground, the body ecu is not sending the signal to turn on the relay. Possible bad body ecu or wire short.
Just out of curiosity, how did you test the Head LP relay? Did you swap another working one or test it on a bench with a meter and power supply? It sounds like the Head LP relay is not engaging or there is broken wire somewhere between the relay and the low beam fuse.
Check and confirm the followings:
1. Check #2, #5 pin on the HEAD LP relay socket, Both should have +12v. If there is no +12, possible blown 30A fuse in the fusible link.
2. Turn on low beam and use a DMM to test pin #1 on the Head LP relay socket for ground. If pin 1 doesn't go to ground, the body ecu is not sending the signal to turn on the relay. Possible bad body ecu or wire short.
Any chance the MPX box plays a role in this? I think you posted in this thread before...
Since op mentioned the low beam indicator does come on on the dash, the stalk switch seems working, and the mpx is sending out the proper low beam signal. But there is still chance that one of the mpx box is faulty somewhere there.
Just out of curiosity, how did you test the Head LP relay? Did you swap another working one or test it on a bench with a meter and power supply? It sounds like the Head LP relay is not engaging or there is broken wire somewhere between the relay and the low beam fuse.
Check and confirm the followings:
1. Check #2, #5 pin on the HEAD LP relay socket, Both should have +12v. If there is no +12, possible blown 30A fuse in the fusible link.
2. Turn on low beam and use a DMM to test pin #1 on the Head LP relay socket for ground. If pin 1 doesn't go to ground, the body ecu is not sending the signal to turn on the relay. Possible bad body ecu or wire short.
I tested out this method and on pin # 1, I get resistance, but not enough ground to make my dmm beep for continuity, so does that suggest a wire short? If so, why isnt my low beam fuses blown? And where can I start looking for the short? Should it be somewhere inbetween the fusebox and the relay itself?
P.S. swapped out the stalk switches, same result. No low beams. Now I’m out $75 for nothing 😞
I tested out this method and on pin # 1, I get resistance, but not enough ground to make my dmm beep for continuity, so does that suggest a wire short? If so, why isnt my low beam fuses blown? And where can I start looking for the short? Should it be somewhere inbetween the fusebox and the relay itself?
P.S. swapped out the stalk switches, same result. No low beams. Now I’m out $75 for nothing 😞
Do you know how a mechanical relay works?
In short a low energy circuit gets a signal, this signal drives an electromagnet, the electromagnet closes a switch connecting the battery +12V to your headlights in this case.
Pin #1 is part of the electromagnet circuit. When off, it floats. When triggered by the body computer, it goes to ground making a circuit. Place your test lamp ground to Batt Neg. Stick the probe in pin#1 and turn the lights on. Do NOT use a 55w lamp. Just a low voltage/low current test lamp.
Google schematics for relays. It will help. Many systems use high level logic (+12v) to trigger subsystems. Others like this one use low level logic -12v = ground to complete the circuit and trigger the relay.
Do you know how a mechanical relay works?
In short a low energy circuit gets a signal, this signal drives an electromagnet, the electromagnet closes a switch connecting the battery +12V to your headlights in this case.
Pin #1 is part of the electromagnet circuit. When off, it floats. When triggered by the body computer, it goes to ground making a circuit. Place your test lamp ground to Batt Neg. Stick the probe in pin#1 and turn the lights on. Do NOT use a 55w lamp. Just a low voltage/low current test lamp.
Google schematics for relays. It will help. Many systems use high level logic (+12v) to trigger subsystems. Others like this one use low level logic -12v = ground to complete the circuit and trigger the relay.
I apologize as I dont have very much knowledge when it comes to electrical components. I do have a low voltage test lamp I purchased from walmart a few days ago, will test this to see if I get ground. Basically the lamp should light up for ground when I switch the low beams on? (Tester probed in pin #1).
Both Low Beams not working
