Here's a weird one. Headlights dim on left turn

[wegngis]

Just like it sounds, last night my headlights (and everything else electrical, come to think of it) were dimming, the fan ran slower, blinkers slowed down. This happened only on left turns, and I had to be going at least 10mph for it to happen. My battery is not flopping around. The only thing I can think of is water somewhere is sloshing and causing this. Any ideas?

 

[asinor]

Loose connection somewhere.

 

[Dave]

Power steering?

 

[wegngis]

Power steering?

Nope. Human steering. ;D

 

[DuctTape]

Was the previous owner's last name zoolander?

 

[DuctTape]

Loose connection somewhere.

Kidding aside, that would be my bet. I suppose it's possible your bulb socket is corroded and the inertia causes it to come loose a bit.

I had weird problems with both headlights and taillights. I r and r'd everything, redid the grounds, and they work fine now.

 

[Bronco_Rider]

It is a grounding issue. Check the ground wires at the turn signals front and rear tail light area. I would also check head light grounding wires and make sure the body is grounded to the engine-frame.
Should be simple

 

[wegngis]

You know what, I just replaced my ground battery cable. Through some weird coincidence, I ended up with the wrong color wires on my battery, so I took the red that had been on negative, put it on positive where it belonged, then I took a new negative and installed that. Everything went right where the old stuff had gone. I wonder if it's related?

(Don't worry, I wasn't installing things backwards, I just had the colors goofed up from a couple rounds of "hey, I just need this fixed" sort of stuff)

 

[matts70]

A corroded dimmer switch will make the instrument gauge lights fail. I could see it as a potential culprit. It's quick and easy to check and clean too.

 

[DirtDonk]

When you made your new ground cable, did you make sure that you reinstalled (if there was one that is) the body ground?

Try this as a test. Make up a jumper wire and connect it from the battery negative to the core support or right to the stud/screw where the headlights are grounded.
See if this changes things.

While you're doing that, make sure that the existing grounds from the headlights and turn signals are still in good shape and connected to the core support.

Paul

 

[wegngis]

Just to update this issue, last night I was driving and the lights decided to just go crazy on me. The dash lights would turn off, then on, then off, then dim, then on, then off, etc. The headlights would dim, then flash, then on, then OFF (exciting at night, let me tell you) then on again, independent of the dash lights. I arrived home a very frustrated man, let me tell you. I'm going to start digging into grounds & such.

DirtDonk, I'm not sure where the negative should ground from the cable. There is a pigtail on the new cable, I thought it was for accessories or something, but I guess I'm supposed to attach it to the body?

 

[Fireball05]

Should run a ground wire from negative cable directly to body. That's quick and easy - do that first and if that doesn't work start chasing individual connections as noted above.

 

[ryansbronco]

its sounds like a bad dimmer switch
but if its only when turning left it could be a short in the column

 

[brianstrange]

It is a grounding issue. Check the ground wires at the turn signals front and rear tail light area. I would also check head light grounding wires and make sure the body is grounded to the engine-frame.
Should be simple

+1 I bet you have a poor headlight ground.

 

[ransil]

sheet metal screw make shitty grounds......

 

[wegngis]

+1 I bet you have a poor headlight ground.

I've found that my headlight plugs are just corroded and really messed up. Not the headlight, the plug. Is there a good way to clean these? I worry about breaking them trying to take the connectors out, and I don't want to replace them since then I'll have to splice everything back together, just not good.

 

[Viperwolf1]

No good way to clean them and the wires are probably corroded a few inches back. I would just get some replacement connectors/pigtails.

 

[wegngis]

Hmmm. I have to agree. Is this a regular part, or a Bronco specialty part?

 

[Justafordguy]

Standard part, any part store will have them.