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Headlight switch problems - Midlife?

984 Views 8 Replies 5 Participants Last post by  C0V3R
I've finally got the car back on the road after a respray, and now the headlights and tail lights are doing odd things. When I pull the light switch on, the headlights flicker regularly (ie in a consistent pattern). The lights on the front fenders flicker on when the headlights dim. The tail lights no longer light at all, but the globes are good, no fuses are blown and the brake lights work. To finish off, I think its probably the light switch, as I noticed, and checked that the headlight switch almost sounds like a blinker relay when its turned on (it makes a spring/spark noise in time with the flickering). Do you think the switch is reparable? Dodgey earth? Or? I presume this problem is linked to the tail lights not working. Thanks in advance!
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I had the same identical thing happen to me recently, but mine was in my 72 Ranchero. I to thought it was my headlight switch, and went ahead and replaced it. It didn't help, the tail lights still didn't work, but the brake lights did, kept hearing clicking noises down around the switch, headlights flickered, etc. I started tracing wires under the dash and came across one that was really hot, just behind the glove box. followed it until it disappeared above the ashtray, but below the radio. I had to pull the instrument bezel off just so I could barely get to it. Everything was by feel with my arm stretched through the opening of the instrument panel. I moved what felt like a relay about a half inch, that was attached to the hot wire. After that I haven't had anymore problems with it. I think it was shorting out against the bottom of the radio chasis. I've been wanting to remove the radio and see exactly what it was that I moved, but I haven't had time to get after it lately, and haven't really driven it much since.

You might want to check if there is a connector or relay that might be shorting out, I'm no expert on trouble shooting the problem, but your problems are exactly what mine was doing. I guess I should get out there and see what the culprit was!
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You have a short somewhere, that is drawing excess current. The headlight switch has a circuit breaker in it, and that is the sound you are hearing.

Best way to diagnose these types of things is to disconnect wiring at various places along the path. For example, headlights: disconnect headlights and test. If still there, disconnect harness at firewall and test. You get the idea. Eventually, you'll find the area where the short is occuring and then you can inspect the wiring more closely.

Some people find that the high-beam switch causes this problem, so I'd start there, as it is close by and simple to get at.
The clicking sound you are hearing is a built in circuit breaker. It is of the re-setting variety. It appears you've created a short somewhere after the switch. The breaker will close and then when the current is too high, re-open - thus the clicking sound. This is used in place of a fuse so you don't get caught out in the "boonies" without a fuse and then no lights!

Start pulling apart connectors and tracing back until the breaker stops clicking. Then start looking for a short somewhere.

It wasnt the high beam switch (disconnected), and I disconnected all the front lights and rear lights, but its still doing it. The wires coming from the headlight switch are getting warm, but I couldnt work out which one - they all seemed to be getting warm.
My 66 did the exact same thing, I replaced the switch too, dident help, after doing some searching and tracing some wires down, I finally got in the truck and "heard" where my short was, it was one of the pigtail connection boots that connect to the tail lights, actually my whole connecter was held on by electrical tape because the boot part tore away, replaced the connectors and havent had a problem since. Good luck. James.
If you say the wires at the switch feel warm, I would follow the wire until it gets cold and then move over to the next warm wire until you find a connector that is in bad shape, or is shorting itself out against other wires or metal. It can be a pain in the but, but I found mine that way directly under the radio.

I did check out the other areas first as the other guys have suggested, but all of my wiring was in great shape so it didn't take long to realize it wasn't at any of those points. Yours may be different.
Thanks for you help guys, Im going to have another go at it tomorrow, I've got a sore neck now /forums/images/icons/wink.gif
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