Having headlight/fog issues
Thread Starter
Senior Member
Joined: Apr 2009
Posts: 301
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1994 E420
Having headlight/fog issues
ok so i recently installed low beam hids in my car. I have a couple questions that maybe you guys can answer for me.
1. Are the fog lights supposed to turn on when i turn the headlights on?
2. Does the fog lamp circuit and the drivers side headlight circuit use the same ground?
Symptoms:
When I turn my headlights in the on position they both flick on and work good for about 5 seconds. Also the fog lamps come on but are they are dim. After about 5 seconds the drivers side headlight begins to flicker sometimes cutting right out. With the headlight switch on, the fog lamps are doing the same thing as the headlights (flickering, sometimes dimming out). When i pull the fog light switch out the fog lights both turn on and work perfectly, but the drivers side headlight cuts out completely. (I am having no problems with the passenger side headlight, it has a steady beam, but as i said before both fog lamps are doing the same thing as the drivers side headlight) I measured voltage at the 4 pin connector on my headlight and im getting a constant 14v. But when i move the DMM to where the HID plugs into the headlight harness im getting voltage spikes (sometimes reading as low as 7-8v and sometimes reading as high as 16-17v)
Any help here guys im stuck. Im not sure that the fog lamps are supposed to be on at all?? Almost seems as if the fog lamps are taking voltage away from the headlights
Really like to get this issue resolved. Thanks in advance.
Oh, p.s.--- I swapped around the HID ballasts and bulbs and everything just to make sure it wasnt that and everything checked out. The passenger side headlight is operating properly.
1. Are the fog lights supposed to turn on when i turn the headlights on?
2. Does the fog lamp circuit and the drivers side headlight circuit use the same ground?
Symptoms:
When I turn my headlights in the on position they both flick on and work good for about 5 seconds. Also the fog lamps come on but are they are dim. After about 5 seconds the drivers side headlight begins to flicker sometimes cutting right out. With the headlight switch on, the fog lamps are doing the same thing as the headlights (flickering, sometimes dimming out). When i pull the fog light switch out the fog lights both turn on and work perfectly, but the drivers side headlight cuts out completely. (I am having no problems with the passenger side headlight, it has a steady beam, but as i said before both fog lamps are doing the same thing as the drivers side headlight) I measured voltage at the 4 pin connector on my headlight and im getting a constant 14v. But when i move the DMM to where the HID plugs into the headlight harness im getting voltage spikes (sometimes reading as low as 7-8v and sometimes reading as high as 16-17v)
Any help here guys im stuck. Im not sure that the fog lamps are supposed to be on at all?? Almost seems as if the fog lamps are taking voltage away from the headlights
Really like to get this issue resolved. Thanks in advance.
Oh, p.s.--- I swapped around the HID ballasts and bulbs and everything just to make sure it wasnt that and everything checked out. The passenger side headlight is operating properly.
MBWorld Fanatic!
Joined: Mar 2005
Posts: 2,647
Likes: 8
Youngtimer
if your fogs are coming on with your headlights then it sounds like something is wired up wrong. are you using the OEM lights or aftermarket? i.e. did you have to do a 4pin to 6 pin conversion?
are your hid ballasts plug and play with the headlight plugs, or did you have to do any manual wiring?
it might be a good idea to try and go back to the halogens and make sure they work okay, and then re-do the hid's...
are your hid ballasts plug and play with the headlight plugs, or did you have to do any manual wiring?
it might be a good idea to try and go back to the halogens and make sure they work okay, and then re-do the hid's...
Thread Starter
Senior Member
Joined: Apr 2009
Posts: 301
Likes: 0
1994 E420
Figured out the problem...
Car was in a small accident before i owned it and the drivers side headlight was ruined. The shop that put it back together put the headlight connector back together the wrong way.
Car was in a small accident before i owned it and the drivers side headlight was ruined. The shop that put it back together put the headlight connector back together the wrong way.
