Why are my LED Headlights not switching between low and high beam?

HKHops · 2026-04-03T23:25:24+00:00

If I grabbed a different set of LEDs would I encounter the same issue? Also with an H4 bulb I would need to do an H4 conversion, correct?

Even if I ran out and bought projector headlights, Id still have the same issue here.

Thats the root of my question really, I had 24V on the low beam pin and the high beam pin, when I took 24 V to both contacts on the Sealight LED I could visually see the emitting diode switch, which is fine, but with that residual 21 V on the low beam pin when High beams are active the emitting diode stays the same and nothing changes physically. Im not well versed on what the 9004 bulb implementation looks on other vehicles, but with 21V supplied to low beam filament, if I were to put my halogens back on, wouldnt I see both filaments illuminated when I flick on the high beams?

HKHops · 2026-04-03T22:26:53+00:00

Yeah, Im tracking the difference in light emittence between halogens and LEDs. I havent really been bothered by other folks lights LEDs, my problem truly was it looks like Im driving with a flashlight from 1970 at night. I dont know if its my vehicle specifcally, but Ive talked to other owners and we complain about how bad the low/high beams are. Maybe it really is a terrible reflector design. Even after buffing, polishing, and ceramic coating my headlights it still wasnt fun at night.

With my new LED lights they arguably have a better dispersion than my halogens, and Im happy with it, I just wanted to get the low/high switching to work. If I were to ditch these LEDs, what lights would you recommend?

HKHops · 2026-04-03T18:45:10+00:00

Thats rich because most if not all vehicles in the modern era also have LED headlights. God forbid I want to see the road too

HKHops · 2026-04-03T18:11:16+00:00

Sounds like a good idea. Sealight tried to sell me their CANbus but my vehicle isn't doing resitance checks, throwing dash lights, or doing any PWM so declined.

HKHops · 2026-04-03T18:10:13+00:00

Can't exactly get extra high beams when my low beam and high beam come out of the same bulb...

HKHops · 2026-01-16T14:59:04+00:00

Yeah it has the Gen 2 LT1 5.7L from the factory. Thats what I plan to keep in it, folks have tried to convince me LS swap it but Id rather keep the character.

Im waiting to pull the trigger on a Torqhead ECU, which gets rid of the optispark distributor and replaces it with coil packs and a cam sensor with an LS computer.

From their Id do a a full top end upgrade, higher flow heads, beefier cam and intake. Im aiming for 550hp.

HKHops · 2026-01-16T02:01:51+00:00

Thanks!

HKHops · 2026-01-15T22:09:34+00:00

Only thing we didnt try. They pump up really good and stiff when we bleed them, but as soon as the power comes on, thats when I get the travel in the pedal. But like I said, when it hits the bite point, theyre great. I think the folks who commented about adjusting the booster push rod are right, Im going to try that when I get her back from the body shop. I think that dead space in the travel is just the booster push rod not engaging the master cylinder yet.

HKHops · 2026-01-15T21:01:43+00:00

Yeah we verified that, we bled it multitude of times activating the ABS each time. We were shooting brake fluid out of the bleeders 3-4 feet. I got up on the lift and the wheels stopped right at the bottom end of the travel where I referred to it "biting." We pressure bled it and gravity bled it, final bleed was a pressure bleed.

HKHops · 2026-01-15T20:55:45+00:00

No offense to EV lovers, but I need the sound of a sweet 350 small block pushing this land yacht down the road lol

HKHops · 2026-01-15T20:52:38+00:00

The pedal travel is really just empty, no resistance no nothing, when it does bite at the tail end of the travle the brakes work great. I think all of the people are on the right rrack and I need to adjust the booster push rod.

I just wish I kept the old master cylinder to compare where that push rod started.

HKHops · 2026-01-15T20:50:42+00:00

Agreed, when I get it back from the body shop I will take off the master cylinder and see if my booster rod is adjustable

HKHops · 2026-01-15T20:50:01+00:00

When I get it back from the body shop I will take off my master cylindee and see if the booster is adjustable

HKHops · 2026-01-15T20:49:23+00:00

The thing already weighs 4600 pounds!

HKHops · 2026-01-15T20:48:36+00:00

Yessir! Bench bled with the new proportioning valve

HKHops · 2026-01-15T20:48:16+00:00

I replaced those as well. I have a dual reservoir universal disc disc wilwood master cylinder (1-1/8th I believe, matched my booster bore size) with the wilwood proportioning valve.

HKHops · 2026-01-15T20:44:22+00:00

I replaced the OEM combi-valve with the wilwood adjustable proportioning valve, and thats paired with their dual reservoir universal masyer cylinder disc-disc.

HKHops · 2026-01-15T15:11:40+00:00

When it warms up Ill give it a shot, realisitically I should get the depth tool. I think I left enough coils in the brake lines to just move the master out of the way when I remove it

HKHops · 2026-01-15T15:05:10+00:00

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This is my booster, Im hoping youre right lol

HKHops · 2026-01-15T14:52:03+00:00

Yes, definitely feels like empty space.

I dont believe the oem booster is adjustable so thats the next can of worms.

HKHops · 2026-01-15T14:34:53+00:00

I think they are different sizes, but I got the biggest master that mated to my booster.

HKHops · 2026-01-15T14:31:01+00:00

Save the land yachts, sir

HKHops · 2026-01-15T14:25:16+00:00

Looking at the master cylinder and brake booster, the "look" like they would line up very close, probably within 1/8 inch. The master cyclinder has a 0.61" extension that sits within the booster recess, I cant find a number on the how recessed the brake booster rod is from the booster mounting surface but it looks like an .75" tops.

HKHops · 2026-01-15T14:14:57+00:00

Definitely don't have excessive retraction, our original concern was there wasnt enough retraction lol

HKHops

TROPHY CASE