2nd Gen Non-Engine/Transmission Intermittent Headlight Issue

[BMelhuish]

Intermittently, I my headlights do not work. I can hold the multi-function switch and the highs work. But when I release it, the lights go out. All other lights, except the headlights, work. For no apparent reason that I can determine the lights begin to work as normal. Now, when I say intermittent, this has happened 3 times that I can clearly remember over the last 5 years-most recently last weekend. I recall many years ago that the dealer replaced the switch. I have checked the wiring, grounds and connections and all appear to be ok.

This is a 1998.5 3500. It does not have Daytime Running Lights, Fog Lamps, remote power door locks, or security. It has a tilt wheel and a factory trailer tow package. So, what I'm dealing with is either the headlight switch or multi-function switch. The wiring diagrams do not show any other significant components.

I cannot duplicate this issue. Its occurance is totally random. On the times I clearly remember, the truck has been parked for hours-3-10. I start the truck, put the steering wheel in position ( I may or may not do this before or after I turn on the lights but probably before), and turn on the lights that do not work. I recall that the headlights were used to get to were I parked it. The lights do begin to work, but it hasn't happened often enough so that I can determine that they come on becasue of some thing I did. I also recall (although I don't recall whether it was one of the 3 times) that the lights went out while driving when I went to high beams, but a simple pull on the multi-function switch, they immediately came back on without issue.

Correcting the issue will be a total guess on my part. Several of the times that this has happened, I've been in the woods on back country roads or trails. So, I don't want to ignore the issue until the culprit becomes readily ascertainable. From what I've read here most headlight issues on the 2nd generation are caused by the headlight switch and not the multi-function switch. That would be my guess as well, but I cannot determine that there is anything wrong with the switch. The switch is only $30 from Autozone. I'm inclined to just replace it and wait a year or two for the problem to recurr, if ever. Is there anything else that I should or can check to try to isolate the problem?

Thanks for your help.

 

[JLandry]

Intermittent electrical problems are some of the most difficult to diagnose and permanently repair.

Unless this problem becomes continuos so you can track down the source, the most likely culprits are either the headlight switch on the instrument panel or the headlight relay located inside the PDC (Power Distribution Center). Since you mentioned moving the multifunction switch fixed it at least once, it's also suspect.

Because we're not talking about a lot of money and because of the intermittent nature of the problem, I'd buy all three parts (headlight switch, relay, and multifunction switch) and replace them one at a time until this stops.

Best regards,

John L.

 

[GAmes]

You use the tilt a lot? Look for loose or chaffing wires on the multifunction switch wire bundle.

 

[BMelhuish]

I do use the tilt wheel everytime I drive the truck. Now, the relay, can it get stuck open and then close when it heats up from the current? I haven't ever studied the mechanics of it. In my experience it either works or it doesn't. I'll give the wiring a more thorough examination tomorrow.

 

[TFabian]

I had a similar intermittent problem about a month ago. Headlights wouldn't turn on but all the other lights would come on. The last time, I was going to check the main fuse when I noticed the brake lights are also on the same 40 amp fuse. I depressed the brake pedal to see if my brake lights worked and my headlights came on??? I ended up replacing the headlight switch and have not had the issue again. Still perplexed why the depressing the brake pedal caused my headlights to start working or how the headlight switch could have caused it. Put about 1500 miles on the truck over the last month and have not had any issues with the headlights.

 

[seafish]

Most likely the Headlight switch is failing...older trucks had a problem with them overheating from the dash dimmer control. Pull the switch and look for melted connectors, then replace it. All that being said, once I got a bad headlight switch new in the box, and had to replace it TWICE.

 

[seafish]

The last time, I was going to check the main fuse when I noticed the brake lights are also on the same 40 amp fuse. I depressed the brake pedal to see if my brake lights worked and my headlights came on??? I ended up replacing the headlight switch and have not had the issue again. Still perplexed why the depressing the brake pedal caused my headlights to start working or how the headlight switch could have caused it.

The way it works is something like this....a bad ground (possibly from an overheated terminal) caused the brake circuit to find ground through the headlight circuit ground, thus lighting up the headlights.

 

[hsmith]

As Gary said, check the wiring at the multifunction connector. I just repaired one with the same issue and it was a broken wire. It was on a Chebby, but still the same principal.

 

[BMelhuish]

I found it, I think. I decided to replace the headlight switch. I found one suspect terminal. The one with the blue wire that has the fuse link. The connector is somewhat melted too. My bet is that the contact was loose and sometimes lost contact. As it got hot it made the connection. I'll use a little dilectic grease and put the new one in and see what happens. I believe that is the problem. I did not find an issue with the multi-purpose switch.

As an aside the lower dash has a lot of cracks and broken pieces. I'm epoxying several spots and reinforcing parts of it with little pieces of cut aluminum. I had the top of the dash replaced several years ago. Apparently, the lower dash has the same issues. Two of the spots that I had to epoxy and reinforce are where the headlight switch and A/C controls attach.

 

[Crowhurst]

I had a related problem last month when the gauge illumination failed. I followed the diagnostic procedures in the Factory shop manual, and the headlight switch and gauge light dimmer circuits passed all the tests. In desperation I bypassed the switch, and the gauge lights illuminated. The first two headlight switches I purchased on-line failed almost immediately. I made some enquiries, and was informed that a superior quality switch, now fitted by Dodge as original equipment, is part ECH HL6559 from Echlin Ignition. It has a 3 year or 36,000 mile warranty, and cost me $25 from my local NAPA store. It works perfectly, and the pull action feels more positive than the previous switches. I will still keep the gauge illumination at maximum to avoid overheating the switch.
Nick.

 

[Crowhurst]

I had a related problem last month when the gauge illumination failed. I followed the diagnostic procedures in the Factory shop manual, and the headlight switch and gauge light dimmer circuits passed all the tests. In desperation I bypassed the switch, and the gauge lights illuminated. The first two headlight switches I purchased on-line failed almost immediately. I made some enquiries, and was informed that a superior quality switch, now fitted by Dodge as original equipment, is part ECH HL6559 from Echlin Ignition. It has a 3 year or 36,000 mile warranty, and cost me $25 from my local NAPA store. It works perfectly, and the pull action feels more positive than the previous switches. I will still keep the gauge illumination at maximum to avoid overheating the switch.
Nick.

 

[seafish]

The first two headlight switches I purchased on-line failed almost immediately. I made some enquiries, and was informed that a superior quality switch, now fitted by Dodge as original equipment, is part ECH HL6559 from Echlin Ignition. It has a 3 year or 36,000 mile warranty, and cost me $25 from my local NAPA store. It works perfectly, and the pull action feels more positive than the previous switches. I will still keep the gauge illumination at maximum to avoid overheating the switch.
Nick.

All good info...echlin still makes quality electrical parts IMO...not a bad idea to keep dimmer switch up all the way to keep from overheating, but also kind of a bummer not to be able to turn it down for better night vision...I wouldn't worry myself about it necessarily.

 

[GAmes]

One way to keep the switch cool is to drill some holes in the duct that is below the switch, there isn't enough circulation up in that little corner. I have also replaced every outside bulb except the front parking lights to leds, including the license plate lights. I have relays sending power to the headlights, one each for low and high beam. Turning the dash lights down is a matter of safety, something I learned while flying low level night missions in the Army.

 

[Crowhurst]

One way to keep the switch cool is to drill some holes in the duct that is below the switch, there isn't enough circulation up in that little corner. .

Is this duct only visible when the plastic dash surround is removed, and is it an air duct? I had considered drilling some holes in the plastic surround, above and below the switch.
Nick.

 

[GAmes]

Is this duct only visible when the plastic dash surround is removed, and is it an air duct?

It is the vent duct on the left side of the dash. Remove the facia and it is easily accessed. Also, attempt to have the selector in one of the dash vent positions at night.

 

[Crowhurst]

Thanks for that. I'll get at it.
Nick.

 

[sg5054]

Couple years ago I was booking down the back roads of NH at 50 or so and changed from low to high beams. What I got instead was low to dark! Clicked again to go back to low, what I got was dark. Oh crap! Click, click click at least a a hundred time in ten seconds and then they came back on. Never happened again. Searched all over and couldn't find anything. Never happened again.
I think the ex wet her pants though...