2nd Gen Non-Engine/Transmission Headlights / tail lights

[SAndreasen]

On my 98 when I pull the switch clear out I have headlights but no tail lights If I pull the switch out part way I can get marker and tail lights and fog lights . I put a new headlight switch in Napa warrantied the switch . Starting to think it might be in the multi function switch . I’ve had this happen before but I can’t remember what I did to fix it

 

[brucejohnson]

On my 98 when I pull the switch clear out I have headlights but no tail lights If I pull the switch out part way I can get marker and tail lights and fog lights . I put a new headlight switch in Napa warrantied the switch . Starting to think it might be in the multi function switch . I’ve had this happen before but I can’t remember what I did to fix it

Do the brake lights, turn signals and 4-way flasher work properly in each situation? Pay attention to the brightness of the turn signal lamps. A broken element can fall across to the second element and reroute the power or ground through the alternate circuitry. Headlamps, both low and high beam functioning? Trying to narrow down the power and ground circuits. Any wiring issues/repairs lately?
The wiring is pretty much straight through. Power goes through several connectors and splices. Don't see any detours routed to the multi-function switch for tail/parking lamps, just the high elements of the bulbs.
The common connectors are the headlight switch C134, splice joint S104 and G100. Several other connectors involved but probably not an issue causing the problem observed. Check the contacts in C134, headlamp switch for condition. Could have had times of excess heat due to trailers or extra added current loads in the light circuits. That would affect both front and rear lighting though.
Switch would seem to be the most likely just looking at the wiring diagram, followed by physical bulb checks and wiring.
Since you have replaced the switch, I would start at:
1. Voltage checks at the taillight sockets to confirm voltage, or lack thereof as confirmation.
If no voltage:
2. Check taillights sockets to ground continuity.
3. Check physical condition of the bulbs and sockets.
4. If you suspect the new switch may be faulty...Take an ohm reading on the disconnected/removed headlight switch while activating and deactivating the headlight switch between Pin B2 (from Pink/Red wire connector of switch) to Pin R (from Black/Yellow wire connector of switch) to check the continuity of the switch in action and that it has a solid connection in both parking light and headlight positions.

 

[GAmes]

It is normal to get those lights with the switch part way out. The switch is not your problem.

 

[brucejohnson]

It is normal to get those lights with the switch part way out. The switch is not your problem.

I believe the "no taillights with the switch pulled all the way out" is the oddity. If position 1 (parking) works, position 2 (headlights) should also work for both head and taillights; switch unlikely defective. It's like a lost/bad ground or mis-wire with the headlights energized. Confirmation of proper functioning of high and low elements of all the bulbs may detect an anomaly in current flow through the various circuitry.
Think I'll look into the multifunction switch and high beam schematics a little deeper...

EDIT: Reviewing the schematic, the taillight circuit has its own switch within the headlamp switch assembly. Then reading the R&R instructions brought back a flickering memory, which could be corrupt after all the years that have passed...something flakey with the switch contacts anyway. The pull switch may not be pulling fully to position 2 if the switch was not fully seated in the switch assembly during change. I seem to remember the rotating instrument light variable resistor being a bit wobbly during assembly. I had to push the release button during the installation process, lightly wiggling the assembly and aligning the shaft to fully seat everything. Wasn't happy with the variable resistor function and the push/pull feel...raspy. Took it back to the parts store and got a refund. Went to dealer and the switch was $5.00 cheaper than the parts store. This was around 2003 time period. Smooth variable resistor and better pull and push function. Everything worked. Just a thought.

 

[SAndreasen]

Thanks I’m sure its the switch because I can play with it and get different results . Is it possible to change to a rotary switch

 

[SAndreasen]

Yew all the other lights work like they should it just acts like the switch mover to far or not far enough

 

[petersonj]

Does your truck have a factory tow package with a trailer tow relay? A trailer tow relay operates all trailer lights, consequently removing a large electrical load from the headlight switch. Also, if your headlights are still wired OEM and your truck does not have the Sport Package, then your headlights are not relayed, either. Without a trailer tow relay and a headlight relay, all operating exterior lighting current must pass through the headlight switch. Much heat is generated right at the switch and switch failures can occur. Usually the switch fails because heat generated by poor wiring connector / connectors at the switch cause the failure.

So, have you actually inspected the wiring connection point at the switch? Your new switches may be good, but may not work correctly if the connectors or no longer clean and tight.

- John

 

[brucejohnson]

An oops moment...see below...

 

[brucejohnson]

Is it possible to change to a rotary switch

The connectors, mounting screws and shape of the switches are different. Anything is possible IF you like the Frankenstein monster look.

Yew all the other lights work like they should it just acts like the switch mover to far or not far enough

I assume you had a problem with lighting and put a new headlight switch in, but that did not resolve the issue?
Have you done any recent wiring repairs or additions?
Look closely on the headlight switch plug in cavities B2 and R. I believe they are the taillight wires. IF the truck was pulling trailers with multiple lights, and the truck does not have load relays for the lighting circuits, the connections may have been overheated and are not making a good contact. Or try to firmly wiggle the connector wires and observe the taillights.
Just thinking...there is the possibility of a trailer plug having an issue. However, taillights are a simple circuit and if one switch position works the other should, too. Which loops right back to the headlight switch's taillight circuit through position 2 contact.

 

[brucejohnson]

Trailer Tow circuit

 

[Ozymandias]

Is it possible to change to a rotary switch

I think that one is even worse, it's all plastic. I don't know if this would be an upgrade or a downgrade after all.

 

[brucejohnson]

Yew all the other lights work like they should it just acts like the switch mover to far or not far enough

More questions:
1. What happens to the dash lights when you switch to position 1 - Parking lights position? (Dash light adjustment to full bright)
2. Then position 2 - Headlights position?
If the dash lights go out when transitioning from the parking position 1 to headlights position 2, more than likely the headlight switch is faulty.
Another test to accomplish, assuming I understand the issue is in parking light position 1 you have parking/taillights and in headlight position 2 the parking/taillights go out.
3. What happens to the parking/taillights if you turn the headlights on and switch between low and high beam?

 

[SAndreasen]

This truck is a 98 . It’s a one ton not sure if it has the towing wiring . I replaced the harness at the switch about 10 years ago so it probably doesn’t have that factory tow wiring . I’m going to order an oem switch either from genos or the local dodge place

 

[SAndreasen]

I think that one is even worse, it's all plastic. I don't know if this would be an upgrade or a downgrade after all.

I’ve had the trucks with the newer style switch and never had any problems like I have with the push pull switch but I don’t know if it’s a lot better or not ?

 

[SAndreasen]

More questions:
1. What happens to the dash lights when you switch to position 1 - Parking lights position? (Dash light adjustment to full bright)
2. Then position 2 - Headlights position?
If the dash lights go out when transitioning from the parking position 1 to headlights position 2, more than likely the headlight switch is faulty.
Another test to accomplish, assuming I understand the issue is in parking light position 1 you have parking/taillights and in headlight position 2 the parking/taillights go out.
3. What happens to the parking/taillights if you turn the headlights on and switch between low and high beam?

With the headlights on I have high and low beam . Everything works fine as far as cab lights tail lights and signals and brake lights just no tail lights and head lights at the same time

 

[brucejohnson]

With the headlights on I have high and low beam . Everything works fine as far as cab lights tail lights and signals and brake lights just no tail lights and head lights at the same time

Just thinking out loud...When did the lighting issue start? Is this on "Bumblebee"? If so, any wiring surgery during facelift?
I assume the front parking lamps are on with headlights on. So, just no taillights with both low and high beams.
Sure appears it is a faulty headlight switch contact 2 for the taillights circuit. Did you recently change a NAPA switch under warranty? The same problem before and after?
One more quick question trying to keep things aligned with the ingrained USAF KISS Principle I acquired, along with satisfying the symptomatic circuitry curious cat in me. Do you have dash/instrument lights in each of headlight switch positions, the parking light mode (1) then in the headlight mode (2)? ...cab clearance lights remain on with headlights on? Hmmm....

 

[SAndreasen]

Just thinking out loud...When did the lighting issue start? Is this on "Bumblebee"? If so, any wiring surgery during facelift?
I assume the front parking lamps are on with headlights on. So, just no taillights with both low and high beams.
Sure appears it is a faulty headlight switch contact 2 for the taillights circuit. Did you recently change a NAPA switch under warranty? The same problem before and after?
One more quick question trying to keep things aligned with the ingrained USAF KISS Principle I acquired, along with satisfying the symptomatic circuitry curious cat in me. Do you have dash/instrument lights in each of headlight switch positions, the parking light mode (1) then in the headlight mode (2)? ...cab clearance lights remain on with headlights on? Hmmm....

yes the bumblebee. This has happened a time or two in the past it’s like the switch moves to far or not far enough sometimes you can play with the stick or the knob in the switch and make them work . This time the issue happened about 6 months prior to the accident. All the lights work just not at the same time

 

[SAndreasen]

More questions:
1. What happens to the dash lights when you switch to position 1 - Parking lights position? (Dash light adjustment to full bright)
2. Then position 2 - Headlights position?
If the dash lights go out when transitioning from the parking position 1 to headlights position 2, more than likely the headlight switch is faulty.
Another test to accomplish, assuming I understand the issue is in parking light position 1 you have parking/taillights and in headlight position 2 the parking/taillights go out.
3. What happens to the parking/taillights if you turn the headlights on and switch between low and high beam?

cab lights dash lights all go out as soon as I pull the switch into any of the on positions the only way I get marker and tail lights is by pulling the switch part way to the on position and it will balance just right between on and off and get marker and tail lights no head lights

 

[brucejohnson]

cab lights dash lights all go out as soon as I pull the switch into any of the on positions the only way I get marker and tail lights is by pulling the switch part way to the on position and it will balance just right between on and off and get marker and tail lights no head lights

Thanks for the additional information.
Those indications put the headlight switch high on the suspicion (99.9%) list as the power to those circuits are supplied through the headlight switch in position 1 and 2. There are a couple splice, ground and bulb faults that could have similar results, but those would be very rare and have other obvious indications as well. Plus, those are not in keeping with the KISS principle, just my overactive and analytical organic what-if computer.
I would still check the headlight switch harness plug's contacts for heat damage and a solid connection when the switch is changed.

 

[SAndreasen]

Thanks for the additional information.
Those indications put the headlight switch high on the suspicion (99.9%) list as the power to those circuits are supplied through the headlight switch in position 1 and 2. There are a couple splice, ground and bulb faults that could have similar results, but those would be very rare and have other obvious indications as well. Plus, those are not in keeping with the KISS principle, just my overactive and analytical organic what-if computer.
I would still check the headlight switch harness plug's contacts for heat damage and a solid connection when the switch is changed.

well wouldn’t you know I pulled switch and everything is hunky dory working right again . I’m going to orde an oem switch