No Headlights, unique situation

Hello All.

1998 XJ 4.0 Auto 221,000 miles, good condition. minor lift, off-road a few times per year. No mudding.

Driving home last night in the rain and lost my headlights, high and low beam.

Here is what makes me say unique after reading for a couple of hours trying to find someone with the common problem.

Lamps went out suddenly, hi and low
No blown fuses
no beams when pulling on the high beam arm
hazard switch makes signal and high beam indicators turn on and not flash
turn signal switch in either direction will make all turn lamps flash in super fast mode.
shut the jeep off when I got home and with all the lights off... the parking light mode looked like it was still on and had only about half voltage running to it, even with switch all the way off.
MAJOR UNIQUE CURVEBALL: The AC/Heat selector switch being turned on will do the exact same thing as the hazard switch.

Only electrical issue ever occured on Tuesday when the factory 221,000 mile alternator stopped charging.. I changed it and had no issues since.

Normally I would grab the multi meter and jump right in but I'm at work and hopeful I can just throw a few parts at it and cruise on.. Not having lights is a pretty serious issue going into the weekend.

Thanks for any assistance. I don't mind the multimeter work later today, I'm just hopeful some regulars will say the AC selection knob making the dash lights change is a common problem and I need "xxxxxx" part.

Hank

grounds.

when my front harness ground went wonky my front turn signals would not flash and turning on the headlights would make the turn signal indicators turn on.

checks the front harness throughly, especially where it connects to the mains in the engine compartment.

Remove your headlight switch and check for a melted connector.

Got both the turn and headlamp switch and I'm ready to throw parts at it. I will check the connector very first thing when I get out of work then move to grounds. I'm curious if my Alternator swap on Tuesday is at all related, maybe I messed with the ground at the battery.

Things just got really confusing when the AC knob started turning on dash lights. I'm nervous something was either wet or quit all the way now because the AC knob no longer makes the signal lights come on.

I hate electrical problems. Like mentioned above, check grounds.

fyi, I'm parting a 98 now, if there's other parts you need, let me know.

I don't know much about the 97+ interiors...actually nothing at all, but what I do know about the prior generation is that some of the switches do like to melt and cause issues. So I would say that Bryan C might be on to something, I'd check that blower switch too.

It may not be related to the alternator but if the alternator did something funny on its way out and back fed a ground, it could have melted something.

mac 'hates grounds too' gyvr

So far....

Realized that pulling the arm back for temp highbeams will make the signal and highbeams indicators turn on but the digital odometer goes blank.

All fuses good.

Power making it to the fuses

New headlight switch

New turn signal switch

Found out that its only in the AC circuit that it lights the dash not the vent modes.

Also found out that disconnecting the aux. fan will keep the AC selector from having any ill effect on the instruments.

Checked the headlights with a jumper to verify the bulbs are good.

All harnesses look good under dash.

ANYONE know anything about the light timer when you shut the jeep off? Can this thing be a pain in the butt? Just screwed up and left my Haynes at work, time to google what this thing looks like.

Also due to the issue with the high and low beams causing the indicator lamps. I think I read about a high/low beam switch.

Any thoughts.

Thanks!

grounds
grounds
grounds

BTW did you check all the grounds?

Problem solved.... Grounds.... Pictures to follow. Thanks to all who pushed the grounds! It was the two by the washer fluid filler neck, hiding under the heavy wire loom.

And there was another hiding in the shadow...



Thanks again. Hope this helps someone down the road.

Youth camp road shook the bolts right out of it! sweet deal dude!