headlight/interior/marker light issues

[Huntervf]

Ok, here's the symptoms:

93 ATX: all lights function a-ok with the autolamp turned on. However, turn the autolamp off and ONLY the headlights will turn on with the switch. Turn the switch to parking lamps and nothing at all, no markers, no interior, no fogs, but the warning chime will still sound. Turn the switch to headlights and only the headlights come on. No interior lights, no marker lights, no fog lights, no tail lights, only headlights.

Leave the switch alone and engage autolamp however, and everything works as it should, provided it's dark enough for the autolamp to engage.

Here's what I know:

In the past year there have been a couple times where this same situation has happened, but it mysteriously fixed itself within a minute or so each time. It happened so infrequently that I didn't put much thought into it.

The car has had an intermittent MFS since I got it two years ago. For the most part it's been fine, however sometimes when engaging the turn signals they won't blink unless you wiggle the stalk. High-beam operation is fine. Wiper delay only works on the quickest setting.


Here's what I've done:

I replaced the headlight switch about a year ago, the old one was getting hot for some reason when the switch was turned on. With the replacement switch (salvaged from an unknown year SHO) the heat issue went away and everything was working fine.

Foglight mod.

Fishtank lamps.

In searching I saw reference to a bad MFS causing problems, but none of the symptoms covered everything I have going on. I have not checked fuses at this point... figured before I start looking I'd see what the forum has to say about it.

So, what say you? Bad MFS? Another bad headlight switch? Or some other goofy problem I have no idea about?


TIA

 

[EMB2580]

Have you check your fuses? I have an occasional problem with my auto lamp, sometimes it works, sometimes it doesn't. but they majority of the time it does (about 80%)

 

[Huntervf]

Have you check your fuses?

I have not checked fuses at this point... figured before I start looking I'd see what the forum has to say about it.

 

[etc1006]

The MFS can do squirrley stuff sometimes. IIRC mine was doing some "non typical" stuff before I cleaned it. Take it apart and clean it real good. That'll probably do it.

 

[Tommy's SHO]

Symtom:
Needed DRL's (Daytime running lights).

Here's what I've done:
Took out the headlight switch and cut the brown wire. What that does is eliminates the power to the parking lights. So when the switch is turned to the headlights, only the headlights turn on. With the switch turned to the parking lights, nothing happens. So now I use my headlight switch as a DRL switch.

Furthermore:
The Auto Lamp works perfectly with all the lights on at night......or when going through a tunnel/bridge

So with that said it looks like the brown wire on your car is not connected properly to the headlight switch or it is unfortunately cut somewhere behind the dash.

Let us know what happens.

 

[SuperHO]

ummm...had the same problem in the 92 a couple of years ago...turns out the auto-lamp switch was shorted. Replaced that, and the problem never repeated itself (I had replaced the MFS at that point, with no results whatsoever). Give that a whirl...they're dirt cheap at the pick-n-pull (free if you have big enough pockets).

 

[EMB2580]

...they're dirt cheap at the pick-n-pull (free if you have big enough pockets).

LOL I've done that a time or two myself, not like they'd keep track of piddly sh*t like that anyways

 

[Huntervf]

Looks like we can add my 93 to the list of repair jobbers this Saturday then

I have a MFS, but I don't have an autolamp or headlamp switch. Here's a question, if I disconnect the autolamp switch will the headlight switch still function?

 

[Huntervf]

Ok, checked the autolamp with a known, good working unit and no change. Installed my replacement MFS and no change. I've not yet checked fuses or the headlight switch.

Any other thoughts?

 

[SHOtimer]

I was going to post my own thread, but figured I might tag along here. I just started getting the same symptoms. I will only get headlights with my headlight switch.....and everything will work perfectly with the autolamps.

I'm intrigued to see if a new headlamp switch is what is needed.

Doug