High-beams but no headlights

[adam_cook]

The headlights in my 2003 TJ won't come on, but the high beams will. With the multi-function switch in the headlight position both the tail lights and dashboard light up so I don't think it's a switch issue. I know that's a common problem, but I'm not sure replacing the switch should be plan A here. The side marker lights also won't come on, unsure if this is related.

The high beams are pretty dim so I can drive around without blinding anyone, but I'd like to get this figured out now that it's getting dark earlier. Any suggestions/ideas would be appreciated.

 

[06GEEP]

Check fuses and relays. Could be wiring or connections. There are so many things it COULD be, just start checking the easiest things first, maybe you'll get lucky. Try switching the relays for the high and low beams. If it changes which lights work, there's your problem. I'm old school, and dim headlights tell me a bad ground, but that doesn't fit with no low beams, so again, check everything light related. I'm thinking the MFS may be the culprit, tho. Good luck

 

[Feralkid]

The multi-function switch is the most likely culprit. It could also be the multi-function switch connector. The power for the headlights goes from the battery, through the multi-function switch, and then to the headlights. 18 gauge wire, no relay. This creates heat in the circuit which degrades plastic and causes the switch and connector to disintegrate causing an open circuit at the plug contacts.

The way you fix this is to replace the switch and connector. Also it's a good idea to run some 14 gauge wire fused directly from the battery through relays to power the headlights using the factory headlight power wires to operate the relay coils.

 

[KennethS]

Also it's a good idea to run some 14 gauge wire fused directly from the battery through relays to power the headlights using the factory headlight power wires to operate the relay coils.

This can be easily accomplished with the $25 Toyota headlight kit.
https://toyotaparts.lakelandtoyota.com/oem-parts/toyota-headlamp-assembly-8111060p70


Oh, and by the way high beams are headlights. Headlights have high beams and low beams.

 

[Feralkid]

This can be easily accomplished with the $25 Toyota headlight kit.
https://toyotaparts.lakelandtoyota.com/oem-parts/toyota-headlamp-assembly-8111060p70


Oh, and by the way high beams are headlights. Headlights have high beams and low beams.

Damn, $18.20 x 2, that's an outstanding price. If I still had the OEM sealed beams this would be a no brainer. I replaced the sealed beams with the KC H4 housings a while back.

 

[macleanflood]

Check and clean the grounds on the grill next to each headlight bucket.

-Mac

 

[KennethS]

Damn, $18.20 x 2, that's an outstanding price. If I still had the OEM sealed beams this would be a no brainer. I replaced the sealed beams with the KC H4 housings a while back.

That price is for 2 H4 headlight housings, 2 H4 bulbs, the relay wiring harness, and a bag full ‘o zip ties. If you don’t have a relay setup, that alone is well worth the $18 price.

 

[ItchyDong]

Unplug the multifunction switch and jump the supplied 12v to whatever wire runs the low beams. This bypasses the switch and will give you more direction.

Be the switch, my friend. Think “switchy” thoughts.

 

[CharlesHS]

Check fuses and relays. Could be wiring or connections. There are so many things it COULD be, just start checking the easiest things first, maybe you'll get lucky. Try switching the relays for the high and low beams. If it changes which lights work, there's your problem. I'm old school, and dim headlights tell me a bad ground, but that doesn't fit with no low beams, so again, check everything light related. I'm thinking the MFS may be the culprit, tho. Good luck

Unless the OP installed a stand alone headlight harness such as the Toyota H4 headlight kit; there is no relay in the headlight circuit.
Other than the MFS; there is only a circuit breaker and a 40A fuse.

 

[CharlesHS]

The multi-function switch is the most likely culprit. It could also be the multi-function switch connector. The power for the headlights goes from the battery, through the multi-function switch, and then to the headlights. 18 gauge wire, no relay. This creates heat in the circuit which degrades plastic and causes the switch and connector to disintegrate causing an open circuit at the plug contacts.

The way you fix this is to replace the switch and connector. Also it's a good idea to run some 14 gauge wire fused directly from the battery through relays to power the headlights using the factory headlight power wires to operate the relay coils.

According to the '03 FSM 8W-50-4 the headlights do not have 18 ga wiring; the parking and side markers have 18 ga wiring.
The headlights have 14 ga wiring to and from the MFS with 12 ga wiring from the 40 A fuse (10).
Your '06 also has factory 14 ga wiring.

 

[adam_cook]

Thank you everyone!

 

[B1Toad]

Have you considered burned out lamps? People will say unlikely that both would go at the same time but what happens is one burns out and is not noticed till the other fails. (the lamps are dual filament)

 

[06GEEP]

Unless the OP installed a stand alone headlight harness such as the Toyota H4 headlight kit; there is no relay in the headlight circuit.
Other than the MFS; there is only a circuit breaker and a 40A fuse.

Huh...my bad.

 

[B1Toad]

Did you see this? https://wranglertjforum.com/threads/low-beam-failure-that-wasn’t-the-switch.86405/

 

[adam_cook]

To anyone following this, it ended up being the switch. Thanks all!

 

[KennethS]

To anyone following this, it ended up being the switch. Thanks all!

Install the Toyota relay system and take the load off that headlight switch. $20 and never replace the headlight switch again.

 

[06GEEP]

To anyone following this, it ended up being the switch. Thanks all!

THANK YOU!!
Lol. I was just checking to see if you figured it out.

 

[azrattler]

Check and clean the grounds on the grill next to each headlight bucket.

-Mac

Must say mac, you are one well grounded individual!