Sounds like a relay going bad.
Maybe under hood buy the drivers side battery

 

Is there a relay under the big fuse (40 amp) by the battery? I called the dealer and the service department made no mention about any relay there.

 

Do you have daytime running lights? I just looked at a wiring diagram and there is a circuit breaker in the headlight switch. If the contacts are burned, it would cause heat build up which would cause the headlights to cycle on and off. Other than that, power comes from the battery to fuse #6 and from there to the headlight switch then to the headlight dimmer switch. How long are the lights out before they come back on?

 

Thank for the research. I don't know if I have daytime running lights, I haven't looked but I will. I know that the whole dash, everything, along with "high beam light" will go off with the headlights. That is how I know during the day that they are screwing up. The headlights will go out for no more than a few seconds, then come back on. I varies sometimes, blink out, instant on, blink out, a few seconds or more before on again. Is this circuit breaker in the headlight dimmer switch itself, or is it external?

 

A few more things. When you refer to the headlight dimmer switch is that the one on the dash or on the steering wheel column? Also, what color is the wire going into that switch, there are a bunch of them?

 

From fuse #6 underhood 40A, a red and light green wire feeds the headlight switch. Inside the headlight switch there is a circuit breaker. From the head light switch two wires go to the dimmer switch. Light green with white tracer goes to the left and violet with white tracer goes to the right. Since both headlights use a separate ground, we can rule out the headlight grounds. Each headlight uses a separte circuit inside the dimmer switch so we can rule the dimmer switch out. However, if either headlight wire has chaffed and is occasionally rubbing ground, it would cause the circuit breaker to open. I would remove the headlight switch with the wires still connected, turn on the headlights and feel for any heat buildup in the switch which would indicate a poor connection inside the breaker causing it to warm then open.

My wiring diagram is from Mitchell. If I were betting, I would bet on the headlight switch but then again it could be a poor connection anywhere in the headlight system between the battery and dimmer switch or a wire anywhere touching ground.

 

myself and others have had trouble with the switch. i chose to get a 40 amp thermal breaker to feed a six circuit fuse block and install four relays and let the truck wiring activate them. i eventually did the fog lights off of the two spare fuses

 

wow i know this thread is old as dirt but any chance you could do some type of write up on how to do this. i hate wires and dont understand any of it but i'll try anything to get rid of this problem

 

Sounds like the best fix to me. Way too much current for the factory switch to handle. Engineers should know it would eventually cause problems.

 

Many thanks to all, it looks like I am getting somewhere, where, don't know yet, but at least I have a good place to start. I know what I am doing today. I feel that it is some sort of loose connection just because of the way the lights cut on and off. If it were a heat related item, the time between on and off would be longer as the relay or whatever, would need time to cool off and close the connection. BTW, the truck can be sitting in a parking lot, engine not running and the symptoms will still appear.

 

FOUND IT!!!!!!!! It was the large red wire that feeds the headlight switch. It was getting hot and had melted the plastic plug where it connects with the switch. Now, how to fix it. I can't replace the plug. Can I bypass that one connection safely? How? Can't tell how glad I am to have found the problem! I know that Dodge had a recall on the 3500 series for the headlight switch and I am pretty sure that they have the same setup. I HAVE to have the dealer fix it, they WILL NOT sell me the kit, state law. Any ideas?

 

Good. Now we have to determine where the resistance was that caused the heat. It could have been where the male terminal plugs onto the female switch terminal. Perhaps it could be coming from inside the switch where the contacts have become corroded. Visually, you would likely be able to tell if the connector terminal had the problem. If it was a terminal problem, I would scrape the switch terminal clean, solder a short wire onto the terminal then splice onto the orignial wire and solder with two layers of heat shrink tubing. If it is the switch and I needed it today, I would go to radio shack and get me toggle switch to handle at least 20 amps and solder it in. For long term, replace the orinignal switch, wire in relays under the hood for the headlights as another poster suggested.

 

This problem has been going on for a long time. One of my first moves was to replace the dash switch, very cheap, throw-a-part-at-it. I am on my second switch, so I don't think the switch is the problem. I dissected the dash switch to remove the red wire. It seemed that the female contact was dirty for the amount of currant going through it. I cleaned everything and so far have tested the lights for about 45 minutes. So far, all is well. The switch gets good and warm, but not hot. I am interested in isolating the red wire to a relay to keep the currant away from the switch, I am not sure how unless I add another switch.

 

Blinking

My brother had that on his 97, it was the switch
in the dash.
He replace it with one out of a car

 

damn i got the same problem. my lights blink on and off. all the lights. clearance lights. turn signal lights. taillights too i guess. everything inside including dash blink on and off too. Im just gonna take it to the dealership . Better be free!

 

Check the red wire going into the headlight switch, although yours will probably be different from our 2ed gens.

 

Here is a link about relays, I built my own system.

Daniel Stern Lighting Consultancy and Supply

Floyd

 

i had the same problem all you have to do is put a relay under the dash mine is a motorola brand and run a hot wire from your battery and the red and white wire that plugs in at the back of the switch bind the male end down and run your wire from your relay and plug it into that male end and your problem is solved it take about two hours to do it right but turst me it works.:thumbsup:

 

my truck had the same problem and i tried everything and got so pissed at it i took it to a dealer and they didnt even know so i bought a new switch and hasn't happened since.

 

My dad bought an updated switch and new plug from the Dodge dealership near where I live. They wanted $100 for the switch, or $45 for the updated switch with new plug?? You may check into that. my headlights are doing the same thing, but I rarely drive at night and mine only tend to do it if I turn my high beams on.

 

http://www.lmctruck.com/icatalog/de/full.aspx?Page=26 Here you go, yall should order a free catalog from lmc truck. You'd be surprised at what they have. I have used several of their parts and I can't complain- descent prices too.

 

There was a recall on this check to see if your truck has been updated. Mine just did it with the new switch in it!!! WTF!!! The stealer wanted $$144 for the updated switch new harness shrink tube and such.

 

That's crazy on the price man. My dad bought it down at the local dealer and it was $45 for the updated switch AND the plug. That's crazy. He bought it because it was half the price than it was for the non-updated plug.

 

the new one will work for a little while but trust me it will do it again i put about five switches before i got smart and put the relay.

 

Just wondering if a relay harness from a 1st gen will work. I have an extra one kicking around and might put it use in the 98.

 

I'm not a 1st Gen guy but I don't think they had headlight relays.

Floyd

 

No relays stock.
That's why the headlight switches often fail, they're overloaded.