pharmboy1995

I'm having trouble figuring out what is going on with my headlights. When the low beams are turned on, the high beams glow at about 1/3 brightness and the high beam indicator light dimly glows as well. When I switch to high beams, everything works as it should.
This has been a problem ever since I bought the car, and I have changed to an old foot operated high beam switch, checked the headlight switch in the dash, and taken apart the connectors and grounds and cleaned them/packed them with dielectric grease.
The car originally had fog lights but they have been removed along with the relay that was on the drivers side of the engine compartment. The wiring connectors are still there and I assume this is part of the problem but am scratching my head on how to fix it.
I have searched the forums but can't find this exact problem with anyone else.
Any help would be greatly appreciated!

pwdbychevy

I would say your light switch is bad.

Fuzzman17

A bad or missing ground would do the same thing. It couldn't hurt to clean the grounds. Check the battery to chassis and engine to Chassis Ground if you haven't already.

Check the harness for the fog lights for voltage with the low beams on then with the high beams. The last owner may have installed higher wattage fog lamps and melted the harness.

You could also do a voltage drop test on the headlights. go from the ground of the low beams to the neg battery terminal. A High voltage indicates a bad ground somewhere, Even if it can't be seen.

Hope this helps and good luck.

pharmboy1995

Thanks for the help, I'll check these things out.

JamesC

iTrader: (5)

Whether the following will be helpful or not, I'm unsure:

Headlights
Circuit Operation:

Voltage is applied to the light switch at all times. The light switch includes a self-resetting circuit breaker which opens and closes if the headlight circuit draws too much current. When the light switch is in "Head," the headlight dimmer switch directs current to either the lo beams or the hi beams. Current to the hi beams also flows to the high beam indicator.

Troubleshooting Hints:

If only one headlight doesn't work in both "hi" and "lo", check the ground wiring.

If headlights don't work in just "hi" or just "lo", check headlight dimmer switch.

If headlights flash on and off with switch in "head," isolate short to ground. Operate the headlight dimmer switch to find if the short to ground is in tan or lt grn wires.

If only the "hi'" headlights flash on and off, check lt grn wires for shorts to ground.

If only the "lo" headlights flash on and off, check tan wires for shorts to ground.

If both "hi" and "lo" headlights flash on and off, check the yel wire for a short to ground.

JamesC

pharmboy1995

There must be a short somewhere in the front harness between the high and low beam (green and tan wires). I am getting feedback voltage all through the green wire all the way to the dimmer switch of around 5 volts with the headlight switch/dimmer switch on low beams. I had the entire harness out last year when I painted the engine compartment and changed engines and did a quick inspection in the loom but didn't see anything. I might end up rewiring the whole headlight system.

pharmboy1995

I found the problem: the previous owner had rewired the headlight connectors on the low beams with the common ground in the wrong place (center spade), so on low beams the current was feeding some current through the high beam circuit instead of straight to ground. I popped the wires for low beam and ground out of the connector and reversed them, and now everything works fine. After 3 years of tinkering off and on with this problem, I never thought of that! Thanks for the replies!

darkhorse91

what colors were the wires you switch as I am having the same problem. maybe some pictures?

pharmboy1995

If you're looking at the plug from the wire end (behind the headlight), the ground would be on the left side (black), low beams would be in the middle on the plug perpendicular to the other two (tan wire), and the high beams would be on the right (green wire). My car had the ground on the center (low beam) plug and was wreaking havoc with the lights.

Hope that helps!

darkhorse91

thanks I'll check it when i have light again. damn late night internets

darkhorse91

so i checked the wiring, green and tan were mixed up on both sides. reversed them so tan was in the middle and green was on the right. same thing. headlights full blast, brights glowing, turn on brights, no lights (except parking lamps) time to fix the switch i guess

camarosource

iTrader: (1)

This is interesting. I'm experiencing the same thing with a h4 Kit.. But my factory wire harness is SWAPPED on my 1992 and never had an issue.

According to this forum it's stated it should be:

LEFT = BLACK
RIGHT = GREEN
MIDDLE = TAN


However my 1992 Camaro Z28 with factory sealed low beam is:

LEFT = BLACK
RIGHT = TAN
MIDDLE = GREEN

The middle and right are SWAPPED but I never had any issues. Is that a typo??

camarosource

iTrader: (1)

I have the same issue and yet my factory wiring is the same as yours..

MIDDLE is GREEN and RIGHT is TAN.. Yet it's said this is wrong?

RBob

iTrader: (1)

An H4 bulb is not wired the same as the stock headlights.

RBob.