Electrical Challenge -Head Lights

[xRugby8]

69 C20 350 4sp stick

I have another electrical challenge. When I go to turn on the head lights I get lights every where but the head lights - Instrument panel, front and rear running lights are on and working correctly. In looking at the wiring diagram it would seem to me if there was something wrong with the switch then these other lights would not be on. It also looks like the switch is a breaker; therefore, there is no fuse to replace. Also, I bought new lights plugged them in and nothing.

Any suggestions?

Here's a little back ground -When I bought the truck (over a year ago) I believe they worked. It has just been sitting until recently while I've been making repairs. I also just replaced the old distributor with an HEI distributor, iginition, and coil.

Thanks
John

[JimKshortstep4x4]

Have yiou checked your dimmer switch? They are prone to sticking in the down position. Try working it with the light switch on.

The other suggestion is to check the grounding of the headlights and the radiator support.

Jim

[Longhorn Man]

Sounds stupid, but kick the high beam switch on the floor.
If that doesn't work, pull back the carpet and unplug the switch and look for corrosion, dammage, or a kerfagled condition in general.
Most likely your high beam switch needs replaced (very VERY common problem.

[Longhorn Man]

Sounds stupid, but kick the high beam switch on the floor.
If that doesn't work, pull back the carpet and unplug the switch and look for corrosion, dammage, or a kerfagled condition in general.
Most likely your high beam switch needs replaced (very VERY common problem).

[xRugby8]

Yes, I did try the highbeems switch and I tried turning the lightswitch but still nothing. I will retry this though.

[Maximum Overdrive]

Just had the same problem with a 68 I have and it was the dimmer switch on the floor that needed replaced.

[68 Stepside]

I had the same problem as well. It turns out my dimmer switch on the floor went out. The headlights wouldn't work in high or low. Kinda fun hitting the brights on your way to work at night, and having the headlights turn off

[thisolechevy]

Dimmer switch!!!!!!!!!!!!!!! replace and move on

[mrein3]

Or just check the connections to the dimmer switch. They tend to get furry.

[xRugby8]

I replaced the dimmer switch -Still no lights. Any other suggestions??

[BobbyK]

Probe the connection to the dimmer switch(with a test light).See if you have power going to the dimmer switch.
Make sure the connections on the back of the light switch are well seated into the prongs.
Check the grounds for the headlights.They are located right behind each light and ground to the rad. core support.
And your positive both lights are good?
As rare as it might be you could have had both lights fail at the same time.It's only happened to me once.I was luckey and saw it happen so I knew what had happend.

[mrein3]

Headlight switches do go bad. Being that the lights don't work I would turn the switch on and start at the back of the headlight with your test light.

IF your headlight switch is bad replace it then make it a headlight relay controller. It will be the last time you replace that switch and you'll see a whole lot more with your lights on at night.

By the time the current gets to the headlight through all the factory, small gauge wiring you are below 11 volts at the headlight. Using a relay to direct straight, clean voltage from the battery is the only way to fly on these old trucks. I can't believe the difference it made on my truck.

[BobbyK]

I agree with the headlight relay mod.
I put H4's in my 71 with the relays and it sure lights up the night.



But I guess one thing at a time.
We should let him get the lights actually working 1st eh?

[corvette]

hey, isn't there a circuit breaker for the headlights somewhere that would isolate them from the rest of the lights. i believe it's under the dash. best thing is start at the switch with a volt tester and work your way through. hope this helps.

[xRugby8]

Tested the voltage at the dimmer switch -no voltage. Also (possible unrelated) I leaned against my horn on the steering wheel and no horn. I tried it with the ignition on and still no horn. I'm going back over the schematics to see if there could be the light switch.

[Don R. Dodson]

Rugby, the voltage enters the headlight switch on a brown wire. The brown wire comes from the bulkhead connector. On the engine side of the bulkhead connector the wire (red) comes from a junction block somewhere under the hood. From the junction block the path is via a fusable link to the battery. Needless to say, that it is time to break out the test light or volt meter with a wiring diagram and do some checking. I hope you have the wiring diagram that has been spoken about many times here on this site. Four pages of wiring diagram. Print off all four pages and then tape them together so that you can follow the wires to the headlights. HINT: Start at the dimmer switch on the 2nd page and you will see the dimmer switch has three wires. One wire comes from the headlight switch on a light blue wire. Should have +12 volts on that light blue wire with the headlight switch pulled on. The output of the dimmer switch has two wires. A light green wire and a tan wire. Either one of these wires should have +12 volts depending on the dimmer switch being depressed, and these wires go to the bulkhead connector, and from the bulkhead connector they go to the headlights on a tan or light green wire. Have fun!

~ Don ~