Another headlight thread

[RF600]

I have searched and looked over the inter webs and not found a similar issue.

 

My headlights will not turn on. Dash lights, park lights work. I pulled the switch and cleaned up the contacts. Still no headlights. I can jump the lights at the connector at the headlight switch and I can get the lights to come on.

Thinking that jumping the lights at the connector, would make the switch bad. I purchased a new switch. No headlights. I have cleaned up body grounds. The plugs at the headlights are not melted. I am getting 12v at the connector.

I don't know where else to check. Could it be as simple as needing to relay the headlights with a new harness?

It is a 95 pathfinder 4x2, manual transmission.

[Slartibartfast]

The light sockets showing power but not running the bulbs tells me there's high resistance somewhere in the circuit. I ran into this putting a fish finder on a neighbor's boat once; the meter said the circuit was good, but the fish finder wouldn't come on until we fixed the weak spot in the wiring. The meter doesn't draw enough current for the resistance to come into play, but your headlight filament sure does.

 

It's surprising that the new switch didn't fix it. It's also surprising that it's on both sides. When my switch started to crap out, it only lost one beam on one side. The fact that you've got nothing on either side with either switch tells me it's probably not the switch. The fact that the lights work when you jumper the switch says that the wiring up to that connector is okay.

 

How does the connector for the switch look? If a pin or socket is bent/corroded/crooked, it could be making poor contact with the switch, but work just fine when you put an alligator clip on it to jumper it. The + feeds for the headlights are separate from the ones for the markers/tails/dash lights, so it makes sense that the headlights would go and not take the other lights with them. The hitch is that the right and left light circuits are separate from each other as well (two fuses under the hood), which means that for neither side to work, both have to be bad.

 

The problem can't be further down the line in either direction, since the lights work with the switch jumped over, which rules out wiring, fuses, and grounds. I guess this comes down to a question of which is more likely: an oddly failed stock switch and a DOA replacement, or two contacts in the plug that apparently went bad at the same time.

 

I'd start with the switch plug. You could've had one side go and not noticed until the other side followed suit. When one of my low beams became intermittent, I only knew there was a problem because something was going on and off--and my first guess was that the high beam on that side was sticking.

 

Anyone got a more probable guess?

 

I would hold off on relaying it until you've sorted out the underlying problem. Expecting a dodgy circuit to keep sorta working well enough to trigger the thing that means you can see where you're going seems like a bad idea.

[RF600]

The connector at the switch looks good. No corrosion, nothing bent or broken.

 

Something I forgot to mention. When I checked power at the headlight plug, both sides had power with low beam on. I thought that only 1 leg had power at a time. When switching over to high beam it would drop one side and power up the other side.

[RF600]

I can't edit my previous post.

 

When I'm checking power at the headlight plugs. For clarification when the low beam is on I have power at both legs on the passenger side. On the drivers side only 1 leg has power.

 

When the high beam is on there is power on both sides of each plug.

[Slartibartfast]

This is a weird one.

 

The test was with the switch you cleaned, right? Sounds like the switch contacts aren't adjusted right. It took me a couple tries to get mine so they touched when they were supposed to and not otherwise after cleaning them out. Cycling the switch with the back off and watching the contacts moving around helped. I think I ended up plugging it in with the back off, messing with the contacts to figure out which did what, and then fiddling with them until both sides high/low worked properly. Or just put the new switch in and test again.

 

Even with the misadjustment, it seems like something should be coming on, even if it's not what's supposed to. I suppose it's possible that it's trying to power more filaments than it has the current capability to do, but it seems like that'd be blowing fuses, and it sounds like the driver's low beam should work then anyway. I'm also wondering if you used a cleaner that left some kind of residue on the contacts, but that seems like a long shot. It also seems like the new switch should've fixed it either way!

 

How did this issue start? Might shed some light on it.

[RF600]

This pathfinder I picked up for my brother. I have no history on it. I didn't use any cleaners on the switch. I did move the arms on the switch down some before putting it back together. All contacts are making contact.

 

I have checked the fuses and they are fine.

[RF600]

OK it's fixed.

 

I started from scratch. Making in sure power was getting from the battery to the fuse. It wasn't getting juice.

 

The block that the fusible links hook up to was not making good contact. I pulled it off and it was a bit nasty. (Not Janet Jackson nasty).

 

I cleaned it up and reconnect it to the battery. Headlights work.

 

I guess the moral of this story is always start at the beginning.

 

Thanks for the assistance.

[Slartibartfast]

Good to hear you got it! Odd that the lights worked when you jumped the switch, with a bad + side.

Edited September 29, 2014 by Slartibartfast

[RF600]

That's what I was thinking. Maybe the hot at the switch was for the turn signals?

 

I'm happy that is one thing off my list of things to do.

[Slartibartfast]

That would explain it! Thanks for that, I'll sleep easier.

[RF600]

I slept better.