Headlight switch gone bad?

[dmw319]

here are the pics of the rust under the battery area. its the inner fender that is rusted.

[randy500]

The bottom picture with, the small hole to the left is the one for the ground strap.

[randy500]

Turn on the headlights and run a ground wire from the headlight ground to the negative terminal then check your turn signals, that will get rid of the headlight false ground which I think is occurring through the turn signal lamps.

[randy500]

You only need to ground one of the headlights, the other will get its ground through the core support.

[randy500]

To summarize...your missing 2 ground straps, so fix that first,
1. Ground the core support to the frame, forget about the inner fender because its rusty and the ground is needed on the core support which originally was through the inner fender
2. Ground the cab firewall to the engine.

Then check all your lights again, headlights on and off.

[dmw319]

So run a ground strap cable from negative battery terminal to the headlight ground immediately behind the battery?

Then also the 2 from valve covers to firewall?

[randy500]

Yes that will get you ground where they are needed. I sent my phone number to you via PM, you can text me if you like. That will be quicker.

[randy500]

BTW, to make the ground you can use speaker wire, an old extension cord, whatever you have handy, then fix it up better later. Just don't forget to fix it up later because it will look cheesy if you dont

[dmw319]

Originally Posted by randy500

BTW, to make the ground you can use speaker wire, an old extension cord, whatever you have handy, then fix it up better later. Just don't forget to fix it up later because it will look cheesy if you dont

I added a ground strap between battery and the headlight ground behind the battery and still nothing. I'll give it a go another day wen it's light out and add that engine to firewall ground as well.

I hate this problem!

[randy500]

I figured that would fix it, since it didn't then its no ground at the turn signal housings, either corrosion, bad bulbs or bulbs not making contact. Forgot to say bulb pins in sockets are spring loaded and those springs can corrode and not make contact with the bulb one the bulb is installed, check each by pushing on them with a tool, lights off so no sparks.

[dmw319]

Hey Randy. I could try that. But Why would the turn signals work correctly with the headlights off? Seems if it was anything with the bulbs it wouldn't work either way?

[randy500]

I think the headlights are getting a ground through the turn signal lights but now that you grounded the headlights, if the problem hasn't changed then that's probably not the problem. Poor grounds do create weird problems though, the electricity will take the path of least resistance.

[randy500]

I would say try this too, turn on the headlights and unplug the headlight bulbs from the socket, see how that effects the turn signals. That will isolate the headlight bulbs which is a large electrical load, and it will put the headlight switch into the equation.

[dmw319]

Just tried. With headlights unplugged, I still get the same result.

[randy500]

So that makes it seem like the headlight switch is the problem, let me read the symptoms again,

[dmw319]

Cool. I have videos and pics of all of it if you need.

I might just need to buy a new headlight switch and try it

[randy500]

Left rear blinker is intermittently working
Brake lights fine with headlights off
No brake lights with headlights on

Is that everything?

The turn signal in the dash will usually glow when a bulb is not working on that side. NOt sure why but think its always like that.

[dmw319]

Yeah, Left blinker only works when headlights are off.

I immediately thought a light would be out too, but both blinkers work fine when headlights are iff

[dmw319]

Now my radio doesn't work and neither do my reverse lights (mine are wired to a separate switch the previous owner installed). So, I've definitely got some electrical gremlin somewhere.

My wife was driving behind me at night the other day and said that when I went over any rough bumps, my taillights would come on momentarily and then turn off. Sounds like a bad ground is loose somewhere? I've checked everywhere I know where to look but something isn't right.

[dmw319]

anyone else have any ideas?

[El Dorado Jim]

disconnect all of your old grounds and take some sand paper, clean them up,so you see shiny metal and reattach them....this will assure you have good grounds, sounds like that is your problem....there are several underneath the truck,body to frame,etc................I know it is frustrating, but these are old trucks..

[dmw319]

Originally Posted by El Dorado Jim

disconnect all of your old grounds and take some sand paper, clean them up,so you see shiny metal and reattach them....this will assure you have good grounds, sounds like that is your problem....there are several underneath the truck,body to frame,etc................I know it is frustrating, but these are old trucks..

thanks. I've done this to most of the places I know of...

[slikside]

My left blinker would glow at times like yours is doing, I think it was with the lights on as well. But I think the blinker worked when called upon. Anyway, I ended up running a new, separate ground wire from the left front blinker housing to front bumper bracket (which is bolted to the frame). Problem solved.

But it sounds like you have a couple problem areas if all your tail lights are intermittent as well.

[dmw319]

Originally Posted by slikside

My left blinker would glow at times like yours is doing, I think it was with the lights on as well. But I think the blinker worked when called upon. Anyway, I ended up running a new, separate ground wire from the left front blinker housing to front bumper bracket (which is bolted to the frame). Problem solved.

But it sounds like you have a couple problem areas if all your tail lights are intermittent as well.

yeah I feel like I have a major ground issue somewhere seeing how not even my radio works now.. but I can't find the issue! I'm far from an electrical guru..

[dmw319]

Well this weekend I found a bad ground. The one on the passenger side that connects to the frame under the cab. I replaced it.. but still have the current issue.

Gaaaah!!!