Hi, New to the forum. the headlights on my 72 convertible stopped working. Vacuum is fine, headlights pop up and down nicely...just lost the actual lighting. Is there a headlight circuit on the 72 or would this be the switch? thanks, Lenny

 

Hi Lenny,
WELCOME!!!!
The headlight switch in the dash controls both the electricity to the bulbs and the vacuum to open the headlight doors.
Have you checked to see if both the regular bulbs AND brights are not working? Check the dimmer switch.
If neither works I'm afraid the problem is in the headlight switch.
The switch is difficult to replace because it requires that the dash pad be loosened and moved rearward and down to access the switch.
Sorry but not an easy way out of this one!
Regards,
Alan

 

The circuit breaker for the headlights is in the switch, so like Alan said, that's a possibility. Before anything else, check the dimmer switch like he said, it's by far the most likely to kill the lights. (Assuming that your tail and park lights still work) And they're cheap and easy (?) to replace. If your tail and park lights still work, it won't be the dimmer.

 

As already noted, start with the dimmer switch. A new dimmer switch costs $5 and is really easy to change. The old floor mounted dimmer switches have a really bad habit of corroding and causing problems.

 

Guys, Thanks for the great feedback. Tried the dimmer switch when I first noticed the lights were out...and the tail, park, brake lights work. I'll get a new headlight switch, any recommendations on tech manuals with good illustrations? I've removed and replaced complete dashes, instrument panels and all, but had a good factory tech book to use. Lenny

 

I recently replaced the headlight switch in my 1970. I believe your 72 should be the same.

Disconnect the battery.

Removed the A/C duct from under dash. Mine just slide out but I believe there is supposed to be a screw holding it in. I don't know what's under a non A/C cars dash.

Remove the drivers side kick panel (couple of screws).

Drop the steering column by removing the two bolts under the dash pad. This will allow the steering column to lower about 2".

Remove all the dash pad screws, this allows the dash pad to slide out and down to gain access to the headlight switch. You should have a couple of inches of space to work with from the left side. Be careful with the dash pad as it's brittle and will break easy. If you need more room you could remove the steering column bolts at the firewall and gain a little more room, I didn't have to do this.

At this point you should be able to reach in with a set of needle nose pliers and unplug the vacuum hoses.

Next unplug the electrical connection.

Next you remove the headlight switch ****, and there is a trick to it. Pull the headlight **** to the ON position. Reach under the switch and there is a small button. Push the button in and than you can pull the **** the rest of the way out. This is really easy if you have a new switch in your hand to see where the button is located.

After the **** is removed you will see a big retainer nut that can be removed with a large flat blade screw driver. Once the retainer nut is removed the headlight switch will slide out.

I also replaced my vacuum control lines at this time. I broke off a golf tee and plugged the new line to the old line. I than reached under the dash and pulled the new line through using the old line. I took about 10 minutes to replace the vacuum hoses.

I replaced the entire headlight switch and vacuum hoses in about an hour and I'd never done it before.

I bought a quality made in the USA switch as I didn't want to do this again. It cost about twice what the Chinese switch cost.

 

And a little more info.... I replaced my dimmer switch because it was corroded and would cause the circuit breaker in my headlight switch to trip. You never new when it was going to trip but it was always at the worst time, like driving at speed down a lonely highway late at night. That was always exciting.

The reason I replaced the headlight switch was because it had a small vacuum leak.

 

I don't know what you mean by you tried your dimmer, but you'll be making a mistake if you replace the headlight switch before the dimmer. You can short the light blue wire to the dimmer to either the lt green or to the tan. If any lights come on, you have a bad dimmer. You can also measure on the light blue with a voltmeter. If you have 12v on the light blue, your headlight switch is ok. I've never been a fan of parts swapping until you know they're bad. You could cause unnecessary problems by accident, and by using an aftermarket switch that may or not be up to standards. First step should be measure for voltage on the dimmer switch with headlight switch on. You should have it on the light blue all the time with the switch on, and on one of the other two wires no matter which position the dimmer is in. If you don't have it, you can check your wiring and connection to the headlight switch. I'd also pull the connector off and plug it on to the new switch before I changed it out if you don't have the voltage on the dimmer. If you had the switch out before, it could be a loose connector or broken light blue wire.