headlight problem

[mickeypowa]

Hi guys !

I have a problem with my headlights : it was working intermittently, sometimes working well as soon as I pull the light switch, sometimes not and If I drived on a pothole, the vibration could make the headlight come back !
Since few days, headlights don't work at all anymore, even when I drive on a pothole.
So I guess there is a bad electrical connection somewhere...

All the other lights work (intrument panel lights, tail light, marker lights)

I have changed the light switch 3 months ago because the previous had burnt so I guess it works fine...

I have no dimmer switch (on the column), the previous owner made a bridge between the yellow and brown wires, and with an after market switch to connect the high beam green wire.
But I have never seen the high beam working...

According to the diagram, I have checked with a multimeter, under the column, the yellow and brown wires connected together, and I have 12V there when I pull the light switch...

So what could I check now ?
Where goes the brown wire then ? under the hood ? Should I check something there ?

Thanks a lot !

Mickeypowa

 

[pontiacgp]

check the grounds, the grounds on these car are notorious for causing problems

 

[RegalBegal]

Another thing to check is the headlight plug itself. They are 30 years old and sometimes corrosion occurs on the terminals.

 

[mickeypowa]

Hi guys !!
I have made a few more tests :
I have 12V when I pull the light switch to maximum on the brown/beige wire under the hood, near the battery.
I have 0V at the headlight.

Between I have these parts : what is it ? I think it's 2 big fuses and 2 relays.. Is it stock ? because It seems to be a homemade modification of the previous owner... The relays seems to be connected to the brown wire, and also to the positive side of the battery, protected by a fuse.. ?

What should I do ?

 

[RegalBegal]

That's not stock it's what I call FUBAR. While I'm sure it can be traced it's difficult to do without seeing it first hand. If your electrical ability is limited you might do better to have it looked at by someone more knowledgeable or replace the harness with an unmolested one.

 

[pontiacgp]

if someone put relays in the headlight wiring that usually means the car's headlights have been upgraded

 

[mickeypowa]

Hello guys !!

I am thinking about pulling out these relays and fuses..

I have 2 more questions :
- in the original harness, the headlight low beam wire (brown/beige) coming from the switch only simply splits in 2, to go to the 2 center headlights
- in the original harness, the headlight high beam wire (green) splits in 4 to go to the 4 headlights ?
There is no relays or something else ?

So, normally, in low beam mode, I have only 2 headlights instead of 4 working ? (because on my car I've always had 4 headlights working regardless of high/low beam mode.)

 

[mickeypowa]

Hi guys !!
I guess I have not original headlights, I must have H4 bulbs I think.


I'm back again with some news :
I've made a few tests : there are 4 pins on the relay :


A- one connecting directly to the battery (+) -> always hot
B- one connecting to the headlight switch -> 12v when I pull the headlight switch
C- one connecting to the ground
D- one going to the headlights

I think that the relay should give 12V to D when B is hot.

But when B is hot, I have 0V to pin D... that's why my headlights don't turn on !

So I've tried to connect pin D directly to the battery and headlights turn on !!

SO I guess I have to change the relays I guess, but I don't find it alone : I only find full harness like this :
http://www.ebay.com/itm/H4-Headligh...ash=item360bbe76e3:g:8~AAAOSwo4pYEELx&vxp=mtr

Should I order that ?

 

[Texas82GP]

Hi guys !!
I guess I have not original headlights, I must have H4 bulbs I think.


I'm back again with some news :
I've made a few tests : there are 4 pins on the relay :


A- one connecting directly to the battery (+) -> always hot
B- one connecting to the headlight switch -> 12v when I pull the headlight switch
C- one connecting to the ground
D- one going to the headlights

I think that the relay should give 12V to D when B is hot.

But when B is hot, I have 0V to pin D... that's why my headlights don't turn on !

So I've tried to connect pin D directly to the battery and headlights turn on !!

SO I guess I have to change the relays I guess, but I don't find it alone : I only find full harness like this :
http://www.ebay.com/itm/H4-Headligh...ash=item360bbe76e3:g:8~AAAOSwo4pYEELx&vxp=mtr

Should I order that ?

Mickey, it sounds like it is wired correctly and sounds like the relay is bad. Here's what I think you need. Ships worldwide.
Look at this on eBay http://www.ebay.com/itm/381339520994

 

[pontiacgp]

I would try cleaning the connection tabs on the relay before changing it....