Here is a nice tutorial on the inner workings of the rollover switch posted by Dave Zuberer several years ago. It’s possible you might be able to clean yours up, re-bend some of the contacts and get it to work again, but they are usually pretty worn after 50+ years of use. The reproductions aren’t that great but should give you a few good years of service.

 

Assuming my photo shows this as being the circuit breaker, no, it does not heat up after holding rocker switch either in up or down position. Does breaker occur before or after rocker switch?

Both lugs turn on test light when grounded. So I'm assuming circuit breaker OK

 

Ed:

Time to get serious about this issue. Start at the headlight motors. Open the hood and pin it open. Use a mirror and a good small flashlight and observe the motor electrical connectors. Take your time and remove them. I believe they have a connector that requires you to pinch it and then pull the connector off.

Hookup a separate 12 volt battery (car or drill/tool battery etc or use jumper cables from your own car battery to front of car) and then use 12 AWG gage electrical wire with alligator clips and connect 12 volt hot to one of the electrical tangs on the motor. If using a separate battery from car connect this battery negative to headlight motor ground wire.

The headlight motor should run and either open or close the headlight. Now move the 12 volt test wire to the second headlight motor terminal. The motor should reverse.

If nothing happens, motor or headlight bucket is bad or binding. If motor runs you have a problem with the firewall fuse block or circuit breaker or headlight rollover switch.

With car battery connected and car wiring powered up, use a multimeter and check the voltage at the disconnected headlight motor connector terminals when a helper moves the rollover switch from inside the car. One multimeter lead to test connector and second multimeter lead to chassis ground. Meter set on DC volts, and should read about 12 volts as switch is activated.

Also check voltage at both terminals of the small 30 amp switch circuit breaker. Each terminal should have 12 volts with multimeter connected to terminal and a chassis ground.

Report what you find from these tests.



Larry

 

Before switch.

Larry

 

Thank you. Electrical has always been "mystery magic" for me but yes, time to seriously learn. I'll try your tests. Need some time.

BTW, when I ground out either lug of the circuit breaker my test light illuminates. I would think this indicates circuit breaker is OK.

 

I wouldn't touch anything up front until I verified the switch under the dash. You have 12 volts going in on a red wire from that breaker and then when you hold the switch up it comes out on 1 wire, hold it down it comes out on the other. Use your test light and see if that switch is putting the 12 volts out on the two other wires. You can even unplug that connector off the back of the switch, and short the red wire to either one of the other two wires and the motor should turn one way or the other. That's the only point the up-and-down motor wires are tied together if both directions stop, you would have to have multiple problems up front for both to fail.

 

Precisely, positively, absolutely correct.

 

Ed can start at one end of this circuit or the other...........it doesn't matter. I chose for him to start at the motors and work back to the switch. You advised him to go the opposite way. Either way will work out.

Long ago I had a similar headlight rollover problem. I rebuilt the switch thinking it was bad. Then replaced the circuit breaker. Still no go.

Jumped to the headlight motors as I described and they worked perfectly. Found my issue to be the firewall connector blocks had slightly separated.

Testing the motors first to me is best and easiest..........but maybe that's just me. My car has factory AC and switch access was a bit difficult and I found the switch block connector (3 wire at switch) to be rather fragile. So I thought OP might be better starting at the motors and also verify circuit breaker was energized and working properly.

The main thing for the OP is to pick a place to start and work from that point to the other, testing each electrical component for proper operation as he goes. He can decide where to start.

OP needs to be advised that motors (if working correctly) will pull quite a few amps of (low voltage) current so he should expect some sparking when connecting/shorting/testing things. Quick on/off for jumper wires or making live connections.

Larry

 

They also go thru the same 8-pin firewall connector block..............does that count??

Larry

 

Hey guys, unfortunately I've only had time to get into this on Sundays. Plus I'm splitting Sunday's between this 66 headlight issue and detailing my 64 motor compartment. Excellent time to get in there to detail the compartment since motor is at a rebuilder and will be done soon. Let's see what today brings to the puzzle. I also think starting at the switch is best. As mentioned earlier the buckets rotated slightly as I played with both the switch and firewall connector

 

I should add the reason I'm splitting time between the motorless 64 and this 66 problem is the 64 motor came out and will go back in at my son's high school auto shop which has facilities I don't have at home. I'd like to get motor back in before school is out for the summer. Time..........a luxury I don't have

 

That's true, but they don't tie together there. The 12v on motor up and motor down are on two different wires. The plug could be cocked so the other connections work, but not likely. The first place to start is where both symptoms could be caused by the same issue, the switch. If you don't have 12v going in and out, you're wasting your time up front messing with wiring and introducing extra problems that may not be there now. After you eliminate the switch, you can start anywhere you like, but you'll find more than one problem to cause both motors, and both up and down functions to stop working at the same time. Before I did ANYTHING else, I would measure the 12v on the red wire at the switch and hold the switch one way or the other and see what happens to that 12v. If it stays constant and the lights don't roll, hold the switch up and check for 12v on the yellow wire, or down and see if it's on the green wire. You can replace anything you want, lube anything you want, etc. Without that 12v in and out of the contacts nothing will work.

 

Yep, unplugged connector, jumped connector and bucket up/down works. Continuity tested the switch and that works also. Plugged switch back in and does not work??? Right now have to stop but perhaps contacts in connector dirty??? Switch posts look OK.

 

Right. Dirty contacts might show continuity but have too much resistance to permit sufficient current flow.

Refer back to post #7.

 

My 2 cents; The motors require voltage AND current. The roll over switch contacts have to be clean and making good contact to deliver the current required. The switch may pass the continuity test but may not be able to carry the current. [pitted contacts]. Refer to Bun's info. Keep us informed.

 

Who is Buns? How would you clean female contacts in connector? They're .15" ID but step down to .070" Dia part way down.

But also contacts inside the switch could be pitted, right?

 

Post #10 = Buns. He shows how to take the switch apart.

 

Inside switch is more likely. Take switch apart and clean and try again.

 

OK found Buns. Apparently I've never gone beyond a page 1 post. Did not realize there were multiple pages. Thought Forum at some point deletes earlier threads.

Hey guys, thanks again.

 

Hey Guys, Getting wacked here. While in the midst of the headlight switch repair, detailing the motorless 64 engine bay before motor is rebuilt, and a bad miss in the 85, I contract pneumonia. That put me out of action for 2 weeks. As recuperating I now develop an umbilical hernia requiring an operation. Plus I'm in a one man business and need work time catch up.

I may never get the switch resolved. I appreciate all your previous input. I'll be back at some point.