I have a 1998 Grand Cherokee 5.9, with all the good stuff, including automatic headlights. Recently when they come on, they've started flashing, alternating with the dashboard lights. That is, the headlights go off, and the dash lights go on, then the headlights go on while the dash lights go off. It happens rapidly, at a pace similar to police flashers. I can only wonder what passing motorists think.

When you flip the switch to "On" all the time, it quits. Last night I experimented while driving around. Sometimes when I switched it to automatic, it would behave, but only for a little while.

I vaguely recall chancing out the headlight switch once, but it's been a couple of years ago, at least. Still, I'm a little puzzled that it would go bad…again?

Suggestions? Time for another switch, or should be looking elsewhere?

Thomas

P.S. I'm only 400 miles from 200k! Wish me luck!

 

I'm well over 200k now, but the headlights still flash on automatic. I know using Rock Auto to diagnose vehicle malfunctions is a poor method, but I looked up parts there and discovered an Automatic Headlamp Control Relay and a Multi-Function Relay.

I looked them up because I've discovered that when the headlights are flashing (on the automatic setting) there's a loud clicking coming from under the dashboard above and to the left of the front passenger's feet. Is there a relay under there that's gone bad? Could that be my Automatic Headlamp Control Relay? A new one is only $5. I'd almost be ashamed to "just throw money at" the problem, but five bucks is way cheaper than an hour of diagnostic time with a mechanic, or a community college course in auto electrical theory and diagnosis.

Thomas

 

If you have the fuse block to the right of the passenger foot well like I do in the 4.0, you might want to examine it for green funk oozing from the connectors on the bottom. I got a new one at the bone yard for $15. Still have the old one, it was so corroded from a leak by the wheel well that the layers of it were separating.