Low Beam Light Goes Out When High Beams Turned On

[Jimbarry]

I have an 83 C30 Quad Headlights. Both low beams go out when I hit the bights. I always thought that was normal, am I wrong???

 

[TotalyHucked]

I have an 83 C30 Quad Headlights. Both low beams go out when I hit the bights. I always thought that was normal, am I wrong???

Yep, all 4 should stay on with the highs. You either have 1 filament in each bulb burned out or you have high beams in all 4 locations

 

[KSSB]

I have an 83 C30 Quad Headlights. Both low beams go out when I hit the bights. I always thought that was normal, am I wrong???

Also, check the sockets that connect to the bulbs. There could be corrosion on the plug, or something.

 

[Jimbarry]

Yep, all 4 should stay on with the highs. You either have 1 filament in each bulb burned out or you have high beams in all 4 locations

Thanks, one more list item.

 

[89GMCJimmy]

Squarebody quad headlights often only work one beam (high or low) because of original wiring design where high beams cut off the low beams, or due to common failures in the dimmer switch (on the column) or headlight relays, causing power interruptions to one circuit, leading to issues like only highs working or low beams cutting out when highs are activated. The classic setup grounds low beams when high beams are on, so a bad relay or wiring breaks this, or a faulty dimmer switch sends power to the wrong place.

LMC harness easy well worth the 35
Heavy-Duty Headlight Harness
Part #: 36-3581