headlight issues

[fgross2006]

I have an 84 LX convertible. About 2 years back I started having issues with the headlight function. The normal functionality is if you pull one notch the park lights come on, pule to the end and the headlights come on with the park lights.

If I pull my headlight knob all the way I get headlights but no park lights or dash lights. If I slightly push the knob back inward I can find the sweet spot and I get my park/dash lights on with headlights. But, the headlights flicker now when they didn't used to do that.

I assumed it was the headlight switch. I tried two new switches 2 summers back. Both performed the same way so I returned them and put the original back in thinking I'd try again some other time. Well now it's time. This quirk irritates me. The aftermarket switches I tried were Standard, I was thinking to order one from LMR. They have a headlight switch that is supposed to function with or without fog lights. It might be worth a try but I still keep thinking its a bad ground.

Speaking of fog lights, I installed a front bumper cover from an 84 GT on my LX so I did a fog light set up although not stock. I first noticed this issue at the same time I noticed my fog lights stopped working. After having a stereo shop install a stereo and subwoofer for me around 2 years ago. The shop refused to look at the fog light and swore he didn't touch anything not radio related, but I always attributed the fog light failure and the headlight issue with happening right after I had a stereo installed.

Anybody have insight on this issue?

[bob85gt]

look at your ignition switch. i have had several open up and cause weird problems.

if that is ok a VOM is your best bet.

[fgross2006]

look at your ignition switch. i have had several open up and cause weird problems.

if that is ok a VOM is your best bet.

I actually had an ignition switch issue last summer. First I noticed the AC was intermittently switching on and off, then I noticed I had no directional lights. I replaced it with a Standard because a Motorcraft was real expensive but it solved all the problems I was having last summer except for the headlight issue. So I'm still searching for a fix.

[fgross2006]

Just to update, this is still an issue. I ordered a headlight switch from LMR that supposed to be universal to fog light/non fog light cars. It did not solve the problem and it made finding the sweet spot to get the dash and park lights to come on more difficult so I put the original headlight switch back in. I also replaced the headlight switch connector with an LMR replacement since mine had broken tabs, but I still have an issue with my dash and park lights not switching on when the headlight switch is pulled to first position. Headlights come on with no dash or park lights when the switch is fully pulled. If I slowly push the switch back in and find the spot between 1st and 2nd positions I can get the dash and park lights to come on.

This was never an issue and its been this way for about 2 years. A visual inspection of the wires in the original connector showed all the connections are clean and no dry rot . I cleaned the contacts and pinched them slightly with needle nose pliers to make sure they all bite down on the prongs in the headlight switch. I removed all the wires and transferred them to the new connector. I didn't see any reason to cut and splice.

So far this is the 4th head light switch I have attempted to swap and I'm convinced it's not the switch. Also, when headlights are on they flicker which to me means a bad ground somewhere.

[scenarioL113]

Do you think it could be a ground issue? Bad grounds can cause some stupid gremlins to come out... Instrument clusters can have some green crap growing in the bulb sockets and actually all the electrical connections for that matter

[fgross2006]

Do you think it could be a ground issue? Bad grounds can cause some stupid gremlins to come out... Instrument clusters can have some green crap growing in the bulb sockets and actually all the electrical connections for that matter

the flickering headlights makes me think its a bad ground. The only other thread I found about this issue was on another forum and he describes the symptoms exactly as mine are. He says he determined his issue was a bad switch but how many bad brand new switches can I go through before I determine its not the switch?

https://stangnet.com/mustang-forums/....740474/page-2

[Chuck W]

Well, the headlight ground is up by the lights on the top of the radiator support. Check those out.

[fgross2006]

another update on this issue. I returned the universal headlight switch to LMR and got a stock Motorcraft NOS headlight switch W/O fog lights. No change in headlight behavior. Still doing the same thing. Pull to first position and no dash or park lights. Pull to second position I get headlights with no dash or park lights. Push the knob in slowly between position 1 and 2 till I get the dash and park lights to come on with headlights that flicker.

This is beyond me. I'm gonna have to have an auto electric guy look at it. This is 4 different headlight switches I have tried. And I replaced the pigtail connector.

[85GTGuy]

I think you've proven that the switch isn't your problem. Like previously said, a ground issue sounds like the next avenue to investigate. Have you checked, or even redone, the headlight grounds?

[fgross2006]

I think you've proven that the switch isn't your problem. Like previously said, a ground issue sounds like the next avenue to investigate. Have you checked, or even redone, the headlight grounds?

I dont even know where the headlight grounds are.

[Bentley]

reread post #7... Small black wire on both sides of radiator on top of the radiator support... Held on by some small screws...

[85GTGuy]

Make sure they are making a good connection.... that they are tight and have no corrosion where they make contact.

[fgross2006]

Make sure they are making a good connection.... that they are tight and have no corrosion where they make contact.

Well I found that they had been painted over by the body shop. I pulled both grounds and found the bolts rusty, the contacts bad and painted on so I cleaned the contacts to the bare metal, wire wheeled the bolts and I was really hoping that would fix it but it didn't. Still the same condition. I have to find the sweet spot between the pull knobs first and second position to get headlights and dash/park lights.

[ukravit]

You stated "I first noticed this issue at the same time I noticed my fog lights stopped working. After having a stereo shop install a stereo and subwoofer for me around 2 years ago. The shop refused to look at the fog light and swore he didn't touch anything not radio related, but I always attributed the fog light failure and the headlight issue with happening right after I had a stereo installed".

Have you looked at the fog light and stereo connections to see if they tapped into any wires that may go to the light system for power or ground? Seems easy enough to just follow the wires from the fog lights and radio and see where they go and when you see a splice or wad of electrical tape look closer. May be something simple.

[massacre]

I agree with using a volt meter. Just to see if the switch is sending 12v to the correct wires when the switch is in the different positions. That should give a starting point. Then you can follow the circuit from the switch to the end of the circuits.
Good luck, i have seen a lot of strange things happen with hidden corrosion and/or broken wires internally. Sometimes wires look fine from the outside but are damaged inside.

[fgross2006]

You stated "I first noticed this issue at the same time I noticed my fog lights stopped working. After having a stereo shop install a stereo and subwoofer for me around 2 years ago. The shop refused to look at the fog light and swore he didn't touch anything not radio related, but I always attributed the fog light failure and the headlight issue with happening right after I had a stereo installed".

Have you looked at the fog light and stereo connections to see if they tapped into any wires that may go to the light system for power or ground? Seems easy enough to just follow the wires from the fog lights and radio and see where they go and when you see a splice or wad of electrical tape look closer. May be something simple.

I did fix the fog light issue and the stereo installed did break 1 line that connected to the fog light switch. I had to remove the switch to see where it detached from but I did fix that and got my fog lights working again.

As for the stereo, I set up the amp and sub woofer after the stereo was installed so I don't know where he got his voltage connection.