goofy headlights!

[Deleted User]

Something is goofy in my headlight system. When I turn the headlights on, they stay on for a minute or so, then blink out again. A few seconds later, they come on, stay on for maybe 20-30 seconds, then out again. This seems to get more pronounced as the motor and wiring gets warmed up a bit. This goes on continuously all the while I have the switch turned to headlights.
I'm thinking - bad headlight switch, but not sure. Also if I turn the switch to first notch, I get keyhole light but no dash lights. Park lights do come on with first notch, and go out on second notch - as per normal I think. Signals seem to work ok.
??? Any ideas? (I'm using the original six volt system)

silverone

Unknown

I believe this intermittent on-off condition is caused by the circuit breaker which is located under the dash (possibly near the light switch). Not owning a Step-Down, I can't tell you precisely what remedy to pursue, but I wanted you to rest assured that at least there are not ghosts in the system.

Unknown

You either have a short in your wiring or a bad headlight switch. Try replacing the switch first & if that does not do it, start checking for a short. What year Hudson are you working on?

Unknown

That's the correct sequence for the parking lights. Sounds like a short, switch problem or maybe even a bad ground wire. Also, if your wiring harness is the original, or has some age on it, you could have a bad or frayed wire somewhere between the switch and headlights that is grounding out. Check the continunity with a multi-meter. What about the tail lights and tag lights? What's going on with them?

[Deleted User]

Check the wiring close to the horn relay on the fire wall.

Randy

Unknown

The car is a '53 Hornet Coupe. That's an interesting question as to what's happening at the other end when the headlights are doing their thing. Could be another clue as to where the problem is, as I think if the tailights were going out also at the same time, then one would suspect the switch more than a relay, would one not? I'll check this out as soon as I can, and we'll soon see.
Anyone know a source for a new headlight switch?
The comments are much appreciated --- thanks.

silverone

Unknown

Also, while I was poking around under the dash, I discovered a white plastic knob that protudes down through the housing on the side where the ignition key is, that feels like some sort of reostat. Turning it fully one way or the other makes no difference at all in anything I can see, but then again -- I have no dash lights yet, so I can't see if they are dimming down or not.
Is that what this thing does --- dims the instrument lights?

silverone

Unknown

Yes, that is the instrument light dimmer. The on / off problem - are the headlights glowing brightly when they are on, or rather dull? If dull, you will have a ground in the wiring loom to the headlamps or the Tail-lamps. The rear wiring is the prime suspect here - check for shorts to ground where the wires run around the trunk, particularly where they are clipped to the frame. If all the lights are glowing brightly when on, it could be the switch overheating. These things can drive you crazy, particularly if you are trying to trace coloured wiring, as by the time they are 50 years old they all appear the same yellowy brown colour! Good luck,
Geoff, N.Z.

Nevada Hudson

My '51 Hornet was doing the same thing. Found that the wire to the hood emblem light was bare in one spot, and grounding. I taped the wire up, and the headlights worked great! If your Hudson has the original wiring, check for bare spots that could be grounding.

Unknown

Yes, this is the dash light dimmer rheostat. On the circuit breaker problem, check that the head lights and tail lights are glowing brightly when they are on. If they are not full brightness it is most likely a short to ground in the harness somewhere causing the circuit breaker to trip. Check the wiring harness, particularly in the trunk, where the wires are clipped to the body. It could be a faulty headlight switch, but I doubt it. Good lulck,
Geoff, N.Z.

Unknown

Thanks Geoff --- I'll check it out from that perspective too.

silverone

Unknown

Sorry, I repeated myself, thought the first one had gone astray! Sorry 'bout that chief!
Geoff.