2000 explorer no taillights or dash lights

[Jay Mann]

Has anyone had this issue before? I changed the headlight switch and they worked again for a couple days and now they are out again. any help would be appreciated. thanks in advance.

 

[TsherryUSA]

I guess first look would be checking the fuse. If you have a multimeter you can start to see where power is / isn't going. So headlights are working, but tail and dash are not? Brights?

 

[J_C]

I would tackle them one at a time. A multimeter comes in handy for this sort of thing if you have one.

I'd check fuse #11 in the interior panel, that it's not blown but also that 12V is getting to it (12V between it and any chassis/ground point).

Next I'd check whether 12V is making it to the headlight switch tan/white wire. With the headlight switch on, I'd check whether 12V is making it to the tan/black wire. If it is not, or while you're at the switch anyway, you could check resistance across the switch pins that the two wire colors above connect to, which should read close to 0 ohms.

Next is the parking lamp relay, pin 4 should have minimal resistance to pin 3. You can pull the relay out to test it directly, does not need to be in the vehicle. You can also try swapping another of the same type relay into the park lamp relay position.

If you have a multimeter extension wire you can test for resistance between the brown wire coming from the parking lamp relay pin 3, and the positive lead on the left or right tail light socket light-green wire.

While you're at the socket you can check resistance between the socket black wire and any chassis ground, should read close to 0 ohms. Attached is the wiring diagram.

2nd attached diagram, "interior lights courtesy lamps" is probably showing the portion of the circuit where the dash light power is stopping, somewhere on it. You'd do similar to the above, tracing it through the interior fuse #26, battery saver relay, interior lamp relay, then the dimmer module. As above you can swap in different relays of the same size, or with the dimmer module sometimes it needs disassembled, the tracks cleaned and re-greased. There is a good forum topic here about that along with pictures.

The output of that diagram goes to the "instrument illumination circuit" to the dash lights, so you could measure whether you have 12V there, making sure you have the dimmer module wheel set to have the lights on, and by "12V" I mean the voltage will vary based on the position of that dimmer module control dial.

 

[TsherryUSA]

Might not apply to Explorers, but an ex had a Subaru Forester that had a similar issue: No dash lights, when headlights on. We kept a small flashlight by the driver so we could check speed when driving at night. If I remember, I ended up tracing the problem to a bad relay.

 

[Jay Mann]

I would tackle them one at a time. A multimeter comes in handy for this sort of thing if you have one.

I'd check fuse #11 in the interior panel, that it's not blown but also that 12V is getting to it (12V between it and any chassis/ground point).

Next I'd check whether 12V is making it to the headlight switch tan/white wire. With the headlight switch on, I'd check whether 12V is making it to the tan/black wire. If it is not, or while you're at the switch anyway, you could check resistance across the switch pins that the two wire colors above connect to, which should read close to 0 ohms.

Next is the parking lamp relay, pin 4 should have minimal resistance to pin 3. You can pull the relay out to test it directly, does not need to be in the vehicle. You can also try swapping another of the same type relay into the park lamp relay position.

If you have a multimeter extension wire you can test for resistance between the brown wire coming from the parking lamp relay pin 3, and the positive lead on the left or right tail light socket light-green wire.

While you're at the socket you can check resistance between the socket black wire and any chassis ground, should read close to 0 ohms. Attached is the wiring diagram.

2nd attached diagram, "interior lights courtesy lamps" is probably showing the portion of the circuit where the dash light power is stopping, somewhere on it. You'd do similar to the above, tracing it through the interior fuse #26, battery saver relay, interior lamp relay, then the dimmer module. As above you can swap in different relays of the same size, or with the dimmer module sometimes it needs disassembled, the tracks cleaned and re-greased. There is a good forum topic here about that along with pictures.

The output of that diagram goes to the "instrument illumination circuit" to the dash lights, so you could measure whether you have 12V there, making sure you have the dimmer module wheel set to have the lights on, and by "12V" I mean the voltage will vary based on the position of that dimmer module control dial.

I guess first look would be checking the fuse. If you have a multimeter you can start to see where power is / isn't going. So headlights are working, but tail and dash are not? Brights?

Every light in the vehicle works except the tail lights and the dash lights. I have front parking lights but nothing in the rear. Like I said everything worked for a couple days after changing headlight switch, now dash and tail lights are out again.

 

[MAS Tequila]

MFS

I had the same thing in a Thunderbird.

I'll bet that one or more of the locking tabs have broken.

 

[J_C]

^ The turn signal front & rear lamps run through the MFS (and would both fail if the MFS had this problem) but the tail light parking lamps don't go through the MFS.

Since the front parking lamps work but the rear don't, we should consider whether this Eddie Bauer has the Lamp Out Module (LOM). The LOM can fail from the internal sense resistors' heat, over time, breaking their solder joint(s). To someone who can solder it may not be hard to DIY repair that and if present it is another thing to check (is under the center console on the floor area), whether 12V is coming out the light green, and brown wires to the lights.

The wiring diagram does not make it 100% clear which of those two colors is for rear park lamps and which is for the turn signals (probably light green is turn signals since it is the color coming from the MFS) so you could put the turn signals on when doing a voltage reading of those two wires to determine that.

If the LOM does not have 12V coming out, also check whether it has 12V going into it on the light green wire (coming from MFS) and the brown wire (coming from Park Lamp Relay). If it does have 12V going in but not coming out, the LOM is bad. If it doesn't have 12V going in, you back trace to the next nearer (to battery) item and swap the relay out with a known good one or measure for whether 12V is getting to it on pins 4 or 5 of the socket it's in.

Note that if the problem is up as far (near the battery in the circuit) as the headlight switch, that the headlight switch does not need to work to turn the headlights on via the mirror slider controlled, autolamps feature. Autolamps (if we assume that circuit still works) can turn the tail lights on if everything else is working, even if there is no headlight switch present... but of course it would have to be dark enough for it to do that automatically.

See the same diagram I posted previously:
https://www.explorerforum.com/forum...hts-exterior-lamps-circuit-1-of-1-pdf.175279/

 

[Turdle]

New headlight switch or junkyard switch? ( first post)

I'm going to suggest another switch

 

[koda2000]

The dash lights and the tail/tag lights are all on the same circuit and fuse. Have you checked the fuse? Does your truck have wiring for a trailer? I've seen funky/worn trailer wiring cause issues with people's rear lighting due to frayed wires shorting out more than once.

 

[Jay Mann]

New headlight switch or junkyard switch? ( first post)

I'm going to suggest another switch

It was a brand new switch. I can't afford a new switch every couple days. Trying to find what's screwing the switch up.